The paper was to explore the effect of trace and secondary elements on scab of cucurbits ( Cladosporium cucumerinum) and their effects on enzyme activities of cucumber plants. [ Method ] Indoor antifungd experiment ...The paper was to explore the effect of trace and secondary elements on scab of cucurbits ( Cladosporium cucumerinum) and their effects on enzyme activities of cucumber plants. [ Method ] Indoor antifungd experiment and pot test was carried out to study the control effect of different trace and secondary dements on scab of cucu.rbits; after trace and secondary element compounds were sprayed for 7 d, the content of soluble protein and malondialdehyde (MDA) and the activities of peroxidase (POD) and superoxide dismutase (SOD) of cucumber leaves during seedling stage were simultaneously detected. [ Result] The inhibi- tion effects on scab of cucurbits were found in the three trace and secondary dements, especially for the CaC12 (66.9%), and about 54.6% and 24.1% for ZnSO4 and H3 BO3 , respectively. When cucumber plants were infected by scab of cuea.rbits, the contents of MDA for all treatments were significantly decreased in cucum- ber leaves after spraying the three trace and secondary elements compared with control. The contents of soluble protein in cucumber seedling were increased by Zn- SO4 and H3 BO3 application, while the contents of POD and SOD were increased on ZnSO4 and CaCI2 treatments. The defense system of cucumber was induced and strengthened by application of the three trace and secondary elements. [ Conclusion ] The results provided the theoretical basis for practical application and research on resistance mechanism of using trace and secondary dements to control scab of eueurbits.展开更多
In 2010, a foliar and stem-lesion disease that produced moderate to severe defoliation of watermelon was observed in the southern Great Plains. The disease was ultimately determined to be caused by Myrothecium roridum...In 2010, a foliar and stem-lesion disease that produced moderate to severe defoliation of watermelon was observed in the southern Great Plains. The disease was ultimately determined to be caused by Myrothecium roridum. The objective of this study was to compare the susceptibility of the vegetation and fruit of a broad range of commercially important cucurbits to three isolates obtained from these foliar lesions on watermelon. In greenhouse foliar inoculation experiments, cantaloupe, honeydew, cucumber, squash, and watermelon were susceptible to the fungus with cantaloupe and honeydew being the most susceptible and watermelon the most resistant. Furthermore, greenhouse inoculations supported earlier field observations as differential resistance was exhibited among the watermelon cultivars as well as the cucurbit types. All tested cucurbit fruit exhibited interior lesions when inoculated sub-epidermally with M. roridum isolates. However, natural infection of watermelon and pumpkin fruit has never been reported.展开更多
Phenylalanine ammonia-lyase (PAL), the first enzyme of phenylpropanoid pathway, is always encoded by multigene families in plants. In this study, using genome-wide searches, 13 PAL genes in cucumber (CsPAL1-13) an...Phenylalanine ammonia-lyase (PAL), the first enzyme of phenylpropanoid pathway, is always encoded by multigene families in plants. In this study, using genome-wide searches, 13 PAL genes in cucumber (CsPAL1-13) and 13 PALs in melon (Cm- PALl-13) were identified. In the corresponding genomes, ten of these PAL genes were located in tandem in two clusters, while the others were widely dispersed in different chromosomes as a single copy. The protein sequences of CsPALs and CmPALs shared an overall high identity to each other. In our previous report, 12 PAL genes were identified in watermelon (CIPAL1-12). Thereby, a total of 38 cucurbit PAL members were included. Here, a comprehensive comparison of PAL gene families was performed among three cucurbit plants. The phylogenetic and syntenic analyses placed the cucurbit PALs as 11 CsPAL-CmPAL-CIPAL triples, of which ten triples were clustered into the dicot group, and the remaining one, CsPAL1-CmPAL8-CIPAL2, was grouped with gymnosperm PALs and might serve as an ancestor of cucurbit PALs. By comparing the syntenic relationships and gene structure of these PAL genes, the expansion of cucurbit PAL families might arise from a series of segmental and tandem duplications and intron insertion events. Furthermore, the expression profiling in different tissues suggested that different cucurbit PALs displayed divergent but overlapping expression profiles, and the CsPAL-CmPAL-CIPAL orthologs showed correlative expression patterns among three cucurbit plants. Taken together, this study provided an extensive description on the evolution and expression of cucurbit PAL gene families and might facilitate the further studies for elucidating the functions of PALs in cucurbit plants.展开更多
Viral diseases are among the most critical damaging factors that impose a global threat to the cucurbit industry.China is the world’s leading country for the production and consumption of cucurbits.Guangdong,a provin...Viral diseases are among the most critical damaging factors that impose a global threat to the cucurbit industry.China is the world’s leading country for the production and consumption of cucurbits.Guangdong,a province in southern China dominated by the tropical and subtropical climate,favors the survival of different plant viruses and their vectors.Five main cucurbit crops showing various disease symptoms were surveyed and collected to identify viruses infecting cucurbits in Guangdong during 2018–2020.In the field,the incidence ranged from 5-30%,or even 60-100% in the case of severely infected cucurbits.A total of 357 symptomatic samples were collected and subsequently screened for cucurbit viruses by small RNA deep sequencing and assembly(sRSA).Seventeen virus species belonging to 10 genera were identified in the five main cucurbit crops.The most common viruses were papaya ringspot virus(PRSV;Potyvirus),zucchini tigre mosaic virus(ZTMV;Potyvirus),zucchini yellow mosaic virus(ZYMV;Potyvirus),and watermelon silver mottle virus(WSMoV;Orthotospovirus),with infection rates of 24.4,19.0,17.1,and 14.3%,respectively.Notably,the most prevalent viruses were melon yellow spot orthotospovirus(MYSV)in cucumber,PRSV in squash,cucumber green mottle mosaic virus(CGMMV;Tobamovirus)in bottle gourd,WSMoV in white gourd,and ZYMV in luffa.Mixed infections were prevalent,and the types of mixed infections varied substantially in different cucurbit crops.Moreover,the full-length nucleotide sequences of watermelon green mottle mosaic virus(WGMMV),CGMMV,and watermelon virus A(WVA;Wamavirus)identified in bottle gourd were cloned and analyzed.This study is the first reporting WGMMV infecting bottle gourd in China mainland.In summary,the results demonstrate that in Guangdong,the most prevalent viruses belong to potyviruses,orthotospoviruses,and tobamoviruses groups.The findings will facilitate agricultural researchers and farmers to plan and implement effective disease control strategies aiming at timely detection and management of cucurbit-infecting viral pathogens.展开更多
The insecticide cartap (CP) is non-fluorescent in aqueous solutions. This property makes its determination through direct fluorescent method difficult. In acidic medium and at room temperature, palmatine (PAL) can...The insecticide cartap (CP) is non-fluorescent in aqueous solutions. This property makes its determination through direct fluorescent method difficult. In acidic medium and at room temperature, palmatine (PAL) can react with cucurbit[7]uril (CB[7]) to form stable complexes, and the fluorescence intensity of the complex is greatly enhanced. Significant quenching of the fluorescence intensity of the CB[7]-PAL complex was observed with the addition of cartap. Based on the significant quenching of the supramolecular complex fluorescence intensity, a new spectrofluorimetric method with high sensitivity and selectivity was developed to determine cartap in aqueous solution. The fluorescence quenching values (AF) showed good linear relationship with cartap concentrations from 0.009 to 2.4 ~tg mL-~ with a detection limit 0.0029 ~tg mE-x. The proposed method had been successfully applied to the determination of cartap residues in grain and vegetable with recoveries of 87.4-103%. In addition, the association constants of the complexes formed between the host and the guest were determined. The competing reaction and the supramolecular interaction mechanisms between the cartap and PAL as they fight for occupancy of the CB[7] cavity were studied using spectrofluorimetry, xH NMR and molecular modeling calculations.展开更多
The inclusion interaction between berberine hydrochloride (BRH) and cucurbit[7] (CB[7]) has been studied by spectrofluorimetry. The result showed that CB[7] interaction with BRH to form a stable inclusion complex ...The inclusion interaction between berberine hydrochloride (BRH) and cucurbit[7] (CB[7]) has been studied by spectrofluorimetry. The result showed that CB[7] interaction with BRH to form a stable inclusion complex with an association constant of 9.57 × 10^4 L/mol and the fluorescence intensity of the complex was enhanced in 17 times higher than that of the studied drug itself. Based on the significant enhancement of fluorescence intensity of BRH in inclusion complex, a spetrofluorimetric method with high sensitivity and selectivity was developed for the determination of BRH in aqueous solution. The linear range of the method was 3.2- 2 × 10^3 ng/mL with a detection limit of 1.1 ng/mL. The proposed procedure could be applied successfully to determination of BRH remained in pharmaceutical dosage forms, spiked human plasma and urine with satisfactory results.展开更多
A new cucurbit[6]uril bridsed binuclear complex {[Gd(H2O)6]2[Q6(H2O)]}C16·4H2O, where Q6 represents cucurbit[6]uril, has been synthesized and characterized by X-ray diffraction. The crystal structure shows th...A new cucurbit[6]uril bridsed binuclear complex {[Gd(H2O)6]2[Q6(H2O)]}C16·4H2O, where Q6 represents cucurbit[6]uril, has been synthesized and characterized by X-ray diffraction. The crystal structure shows that the complex has an extended cucurbit[6]uril-bridged structure consisting of two gadolinium(Ⅲ) ions, in which each gadolinium(Ⅲ) ion is coordinated with two neighboring carbonylic oxygen atoms of Q6 and six oxygen atoms of water molecules that leans toward one side of the portal. One disordered guest water molecule resides in the Q6 molecule cavity and occupies two different positions. Hydrogen bonds assemble the complcx to threedimensional supramolecular structure.展开更多
DNA barcoding is a supplementary tool in plant systematics,extensively used to resolve the species level controversies.This paper details the identification of DNA barcodes for seven species of Momordica,using the chl...DNA barcoding is a supplementary tool in plant systematics,extensively used to resolve the species level controversies.This paper details the identification of DNA barcodes for seven species of Momordica,using the chloroplast gene mat K.Since the species M.cymbalaria has been confused as a member of the genus Luffa,26 accessions of Momordica belonging to seven Indian species and two accessions of Luffa acutangula were included in this study.Analysis of mat K sequences has yielded distinct barcodes in M.charantia var.charantia,M.subangulata subsp.renigera,M.cochinchinensis,M.balsamina,M.cymbalaria and also in Luffa acutangula.Evolutionary status of each species was reflected as nucleotide polymorphisms in each sequence.The wild species M.dioica and M.sahyadrica have yielded one barcode but failed to get differentiated.Further,this study provides conclusive proof that M.cymbalaria is a member of Momordica genus.The phylogram generated was successful to distinguish the monoecious species of this genus,M.charantia,M.balsamina and M.cymbalaria,from the dioecious species M.dioica,M.sahyadrica,M.subangulata subsp.renigera and M.cochinchinensis.Thus,mat K locus,by accumulating the evolutionary sequence variations,is proven efficient to differentiate the Momordica species and to reveal their relatedness.展开更多
pH and temperature responsive copolymers PNAM4VBCB of N-isopropyl acrylamide(NAM) and complex pseudorotaxane monomer N 1-(4-vinylbenzyl)-1,4-diaminobutane dihydrochloride with cucurbit[6]uril(CB[6]) threaded(4V...pH and temperature responsive copolymers PNAM4VBCB of N-isopropyl acrylamide(NAM) and complex pseudorotaxane monomer N 1-(4-vinylbenzyl)-1,4-diaminobutane dihydrochloride with cucurbit[6]uril(CB[6]) threaded(4VBCB) were prepared via free-radical polymerization in aqueous solution.The copolymers were characterized by 1 H NMR,Fourier transform infrared(FTIR) spectrometry,elemental analysis,and static light scattering.The thermodynamic properties of the copolymers were studied by thermogravimetric analysis(TGA),and the effects of pH and the concentration of the copolymer on the average hydrodynamic radius(R h) were studied by dynamic light scattering(DLS).In addition,the thermal sensitivities of the copolymers were studied by DLS and UV-Vis.The experiment data show that CB[6] beads are localized on 1,4-diaminobutane units in the side chains of the copolymer.TGA data show that thermal stability of the copolymers increases with the adding of CB[6] threaded because of the enhanced rigidity and the bulky steric hindrance of 4VBCB in the side chain of PNAM4VBCB.DLS data show that the average hydrodynamic radius of copolymer increases with the increase of the copolymer concentration and has a jump with adjusting pH due to the existing of the small size CB[6] dethreaded from the copolymer with increasing pH.Both pH and electrical conductivity curves of the solution of PNAM4VBCB-4 have a jump because CB[6] could dethread from the copolymers with the addition of NaOH.In addition,the copolymers have thermal sensitivity and their phase-change temperatures could be controlled by adjusting the molar ratio of NAM to 4VBCB in the copolymers.展开更多
Cucurbitaceae family contains important economic and medical crops, they can be divided into two categories according to the worldwide consumption, use, and production. The Cucurbit Popular Crops (CuPoC) are comprised...Cucurbitaceae family contains important economic and medical crops, they can be divided into two categories according to the worldwide consumption, use, and production. The Cucurbit Popular Crops (CuPoC) are comprised of cucumber, the Cucurbita group (pumpkin and squash), melon and watermelon. On the other hand, Neglected and Underutilized Cucurbit Species (NUCuS) group has been used as food sources, medicinal properties and elements in the elaboration of different types of items. The NUCuS is represented in this review work by bitter gourd, bottle gourd, chayote, ridge gourd, and snake gourd, which are recognized mainly in Asia. The center of origin of the majority of NUCuS was proposed to be in the Old World. In contrast, the origin of chayote or Sechiumedule (Jacq.) Sw. was suggested in the New World, precisely in Mesoamerican region based on linguistic uses and distribution of wild relatives. The environmental factors along with artificial selection, production systems and traditional knowledge have been influenced the evolutionary history of NUCuS, Infraspecific variation of chayote has been reported in Mexico over-described varietal groups. These descriptors were determined based on biochemical and morpho-structural traits;however, cytogenetic analyses are scarce. Specifically, chromosome and nuclear content analyses are important to support botanical groups, analyze artificial selection history, developing breeding and conservation programs. The present review paper discusses agronomic and evolutionary importance based on cytological evidence in NUCuS, mainly in the prominent chayote;with the perspective to prompt breeding, conservation, cytology, structural and functional genomics research for its sustainable utilization.展开更多
Enhancing the proton conductivity of proton exchange membranes(PEMs)is essential to expand the applications of proton exchange membrane fuel cells(PEMFCs).Inspired by the proton conduction mechanism of bacteriorhodops...Enhancing the proton conductivity of proton exchange membranes(PEMs)is essential to expand the applications of proton exchange membrane fuel cells(PEMFCs).Inspired by the proton conduction mechanism of bacteriorhodopsin,cucurbit[n]urils(CB[n],where n is the number of glycoluril units,n=6,7,or 8)are introduced into sulfonated poly(ether ether ketone)(SPEEK)matrix to fabricate hybrid PEMs,employing a nature-inspired chemical engineering(NICE)methodology.The carbonyl groups of CB[n]act as proton-conducting sites,while the host–guest interaction between CB[n]and water molecules offers extra protonconducting pathways.Additionally,the molecular size of CB[n]aids in their dispersion within the SPEEK matrix,effectively bridging the unconnected proton-conducting sulfonic group domains within the SPEEK membrane.Consequently,all hybrid membranes exhibit significantly enhanced proton conductivity.Notably,the SPEEK membrane incorporating 1 wt.%CB[8](CB[8]/SPEEK-1%)demonstrates the highest proton conductivity of 198.0 mS·cm^(−1) at 60°C and 100%relative humidity(RH),which is 228%greater than that of the pure SPEEK membrane under the same conditions.Moreover,hybrid membranes exhibit superior fuel cell performance.The CB[8]/SPEEK-1%membrane achieves a maximum power density of 214 mW·cm^(−2),representing a 140%improvement over the pure SPEEK membrane(89 mW·cm^(−2))at 50°C and 100%RH.These findings serve as a foundation for constructing continuous proton-conducting pathways within membranes by utilizing supramolecular macrocycles as fuel cell electrolytes and in other applications.展开更多
Fluorescent poly(N-isopropylacrylamide-co-Nile blue)(pNIPAm-co-NB)microgels were synthesized that exhibited fluorescence intensity changes in a water temperature-dependent fashion.NB is well known to exhibit fluoresce...Fluorescent poly(N-isopropylacrylamide-co-Nile blue)(pNIPAm-co-NB)microgels were synthesized that exhibited fluorescence intensity changes in a water temperature-dependent fashion.NB is well known to exhibit fluorescence intensity that depends on the hydrophobicity of the environment,while pNIPAm-based microgels are well known to transition from swollen(hydrophilic)to collapsed(relatively hydrophobic)at temperatures greater than 32℃;hence,we attribute the above behavior to the hydrophobicity changes of the microgels with increasing temperature.This phenomenon is ultimately due to NB dimers(relatively quenched fluorescence)being broken in the hydrophobic environment of the microgels leading to relatively enhanced fluorescence.We went on to show that the introduction of cucurbit[7]uril(CB[7])into the pNIPAm-co-NB microgels enhanced their fluorescence allowing them to be used for polyamine(e.g.,spermine[SPM])detection.Specifically,CB[7]forms a host–guest interaction with NB in the microgels,which prevents NB dimerization and enhances their fluorescence.When SPM is present,it forms a host–guest complex that is favored over the CB[7]-NB host–guest interaction,which frees the NB for dimerization and leads to fluorescence quenching.As a result,we could generate an SPM sensor capable of SPM detection down to~0.5µmol/L in complicated matrixes such as serum and urine.展开更多
Tomato leaf curl New Delhi virus(ToLCNDV),a bipartite begomovirus,was first reported to infect tomato and has recently spread rapidly as an emerging disease to Cucurbitaceae crops.To date,the virus has been reported t...Tomato leaf curl New Delhi virus(ToLCNDV),a bipartite begomovirus,was first reported to infect tomato and has recently spread rapidly as an emerging disease to Cucurbitaceae crops.To date,the virus has been reported to infect more than 11 cucurbit crops,in 16 countries and regions,causing severe yield losses.In autumn 2022,ToLCNDV was first isolated from cucurbit plants in Southeastern coastal areas of China.Phylogenetic analysis established that these isolates belong to the Asian ToLCNDV clade,and shared high nucleotide identity and closest genetic relationship with the DNA-A sequence from the Chinese tomato-infecting ToLCNDV isolate(Accession no.OP356207)and the tomato New Delhi ToLCNDV-Severe isolate(Accession no.HM159454).In this review,we summarize the occurrence and distribution,host range,detection and diagnosis,control strategies,and genetic resistance of ToLCNDV in the Cucurbitaceae.We then summarize pathways that could be undertaken to improve our understanding of this emerging disease,with the objective to develop ToLCNDV-resistant cucurbit cultivars.展开更多
Programming microscopic assembly mode to control macroscopic property is an attractive research objective.In particular,controlling molecular assembly to control fluorescence is of considerable interest for developing...Programming microscopic assembly mode to control macroscopic property is an attractive research objective.In particular,controlling molecular assembly to control fluorescence is of considerable interest for developing smart fluorescent materials.Herein,a color-tunable supramolecular emissive system was developed based on cucurbit[8]uril mediated host-guest assembly.Chemical designing for the molecular structures with minimized change resulted in different assembly modes and hence generating distinctive fluorescence,including green,yellow and orange with the addition of cucurbit[n]uril.Taking advantage of this feature,the advanced information encryption material(4D code)with multiple encryption levels and time-dependent encryption feature was developed.Such a code was dynamic on time scale,generating a series of 3D codes with time.The encrypted information only can be recognized by integrating time-coursed codes.This work provides a new insight for designing intelligent fluorescent materials for information encryption with high level of security.展开更多
Photoresponsive supramolecular systems have merited extensive attention for their applications in materials science and life science.Here,we synthesized a water-soluble stiff-stilbene molecular photoswitch,exhibiting ...Photoresponsive supramolecular systems have merited extensive attention for their applications in materials science and life science.Here,we synthesized a water-soluble stiff-stilbene molecular photoswitch,exhibiting outstanding photoisomerization reaction between its(E)-and(Z)-configurations upon irradiation at distinct light.The photoswitch can assemble with cucurbit[7]uril(CB[7])to form a superior fluorescent supramolecular complex(compared to the only guest)with excellent water solubility,which manifested dramatic photoluminescence enhancement caused by restriction of intramolecular rotation and remained good photochromic characteristics.Furthermore,introduction of CB[7]influence photoreaction quantum yield(Φ)of the stiff-stilbene,leading to reduction ofΦ_(E→Z) and increase ofΦ_(Z→E) of the stiff-stilbene.Importantly,the photoadjustable supramolecular assembly can act as a fluorescence switch,and the phototunable guest further selectively modulate G-quadruplex structure of Tel22 upon light irradiation or with addition of CB[7].The study provides a new simple way for accurately regulating photochromic properties of molecular switches and developing smart materials with potential applications in controlled modulation of G-quadruplex,targeted biological imaging and so on.展开更多
The binding interactions between 4-aminopyridine(4-AP) and a series of cucurbit[n]urils(Q[5], Q[6],TMe Q[6], Q[7], Q[8]) have been studied using1H NMR spectroscopy, UV–vis absorption spectroscopy,isothermal titration...The binding interactions between 4-aminopyridine(4-AP) and a series of cucurbit[n]urils(Q[5], Q[6],TMe Q[6], Q[7], Q[8]) have been studied using1H NMR spectroscopy, UV–vis absorption spectroscopy,isothermal titration calorimetry(ITC) and X-ray crystallography. The data indicates that the Q[5]@4-AP complex exhibits exo binding, which is not observed in the other four host-guest complexes. Furthermore,X-ray crystallography clearly reveals how the Q[n]s bind with 4-AP to form complexes, for example Q[5]forms an outer-surface complex, whilst Q[6], TMe Q[6] and Q[7] formed 1:1 host and guest type complexes, and Q[8] formed a stable 1:2 ternary complex due to its large cavity, which can accommodate two 4-AP molecules.展开更多
Developing efficient and stable electrocatalyst to hydrogen evolution reaction adaptable for electrolytes with different p H is a big challenge.In this work,a hierarchically structured ternary nanohybrid composed of f...Developing efficient and stable electrocatalyst to hydrogen evolution reaction adaptable for electrolytes with different p H is a big challenge.In this work,a hierarchically structured ternary nanohybrid composed of flower-like Ru nanoparticles,rigid macrocyclic cucurbit[6]uril(CB[6])and carboxylated multiwalled carbon nanotubes(MWCNTs)was successfully prepared by chemical wet method.Benefited by the structural merits of flower-like Ru nanoparticles exposed abundant active sites supported by the MWCNTs holding superior mass transport and electrons transfer ability as well as the existence of CB[6],the obtained catalyst exhibited outstanding HER activities with overpotentials of 27,37 and 70 m V at-10 m A/cm^(2) in alkaline,acidic,and neutral electrolytes,respectively.Under the same electrocatalytic operation conditions,the HER performance is comparable or superior to commercial Pt/C catalyst(47,27and 49 m V).Besides,chronopotentiometric and accelerated stability test also revealed its extraordinary stability,which could be further employed for electrocatalytic procedure in a broad pH range.展开更多
In this paper, cucurbit[7]uril(CB[7])-mediated three-dimensional gold nanoassemblies were successfully prepared to increase the loaded amount of CB[7] and enhance the electrochemical detection of amino acids. Particle...In this paper, cucurbit[7]uril(CB[7])-mediated three-dimensional gold nanoassemblies were successfully prepared to increase the loaded amount of CB[7] and enhance the electrochemical detection of amino acids. Particle sizes of gold nanoparticles(Au NPs) significantly affect stability and detection sensitivity of nanoassemblies. The volume of gold nanoassemblies first increased and then decreased with the increase of CB[7] concentration. The 3D gold nanoassemblies composed of 16 nm Au NPs and 100 μmol/L CB[7]had excellent stability and maximum volume, exhibiting more sensitive detection for a variety of amino acids. And the detection limits of aromatic amino acids are lower in virtue of the higher binding constant between aromatic amino acids and CB[7]. This study will develop and deepen our understanding of molecular recognition in amino acids detection.展开更多
The macrocyclic family comprising pillar[n]arenes and cucurbit[n]urils have received much attention recently. However, studies on the construction of supramolecular complexes formed directly with derivatized pillar[n]...The macrocyclic family comprising pillar[n]arenes and cucurbit[n]urils have received much attention recently. However, studies on the construction of supramolecular complexes formed directly with derivatized pillar[n]arenes and cucurbit[n]urils are scant. Given the interest in such systems, herein we have synthesized a new type of naphthalene-derivatized pillar[n]arene NTP5 and selected Q[10] as the host molecule. The 4-[2-(1-naphthalenyl)ethenyl]pyridine of NTP5 is encapsulated by Q[10] and formed a hostguest complex in water-acetic acid(1:1) solution accompanied by enhanced fluorescence, which changed the morphology of NTP5 from a sphere to a porous form. In addition, the fluorescence of Q[10]-NTP5 can be quenched by the addition of the highly toxic pesticide paraquat(PQ), and the mechanism was shown to be the formation of a new charge transfer ternary system of Q[10]-NTP5-PQ. This work provides new ideas for the contribution of supramolecular assemblies based on derivatized pillar[n]arenes and their combination with cucurbit[n]urils and reveals their potential applications.展开更多
Photodynamic therapy(PDT)agents may accumulate in skin and cause severe skin cytotoxicity.We report a pro-guest-based supramolecular strategy to selectively activate PDT in the reactive oxygen specie(ROS)overexpressed...Photodynamic therapy(PDT)agents may accumulate in skin and cause severe skin cytotoxicity.We report a pro-guest-based supramolecular strategy to selectively activate PDT in the reactive oxygen specie(ROS)overexpressed microenvironment,which is often existing in tumor and inflammatory tissues.PDT agents methylene blue(MB)and basic blue 17(BB17)are used as model drugs.When encapsulated by acyclic cucurbit[n]uril(CB[n]),the efficacy of PDT agents is significantly inhibited.By contrast,in the presence of ROS(H_(2)O_(2))and pro-guest,PDT agents are displaced and reactivated to show a dramatically enhanced PDT efficacy in cells.展开更多
基金Supported by Liaoning Natural Science Foundation Project(20062124)~~
文摘The paper was to explore the effect of trace and secondary elements on scab of cucurbits ( Cladosporium cucumerinum) and their effects on enzyme activities of cucumber plants. [ Method ] Indoor antifungd experiment and pot test was carried out to study the control effect of different trace and secondary dements on scab of cucu.rbits; after trace and secondary element compounds were sprayed for 7 d, the content of soluble protein and malondialdehyde (MDA) and the activities of peroxidase (POD) and superoxide dismutase (SOD) of cucumber leaves during seedling stage were simultaneously detected. [ Result] The inhibi- tion effects on scab of cucurbits were found in the three trace and secondary dements, especially for the CaC12 (66.9%), and about 54.6% and 24.1% for ZnSO4 and H3 BO3 , respectively. When cucumber plants were infected by scab of cuea.rbits, the contents of MDA for all treatments were significantly decreased in cucum- ber leaves after spraying the three trace and secondary elements compared with control. The contents of soluble protein in cucumber seedling were increased by Zn- SO4 and H3 BO3 application, while the contents of POD and SOD were increased on ZnSO4 and CaCI2 treatments. The defense system of cucumber was induced and strengthened by application of the three trace and secondary elements. [ Conclusion ] The results provided the theoretical basis for practical application and research on resistance mechanism of using trace and secondary dements to control scab of eueurbits.
文摘In 2010, a foliar and stem-lesion disease that produced moderate to severe defoliation of watermelon was observed in the southern Great Plains. The disease was ultimately determined to be caused by Myrothecium roridum. The objective of this study was to compare the susceptibility of the vegetation and fruit of a broad range of commercially important cucurbits to three isolates obtained from these foliar lesions on watermelon. In greenhouse foliar inoculation experiments, cantaloupe, honeydew, cucumber, squash, and watermelon were susceptible to the fungus with cantaloupe and honeydew being the most susceptible and watermelon the most resistant. Furthermore, greenhouse inoculations supported earlier field observations as differential resistance was exhibited among the watermelon cultivars as well as the cucurbit types. All tested cucurbit fruit exhibited interior lesions when inoculated sub-epidermally with M. roridum isolates. However, natural infection of watermelon and pumpkin fruit has never been reported.
基金supported by the Young Scientists Fund of the National Natural Science Foundation of China (31101548)the Special Fund for Agro-Scientific Research in the Public Interest, China (201303014)+1 种基金funded by the China Agriculture Research System (CARS-25)the Science and Technology Innovation Program of Chinese Academy of Agricultural Sciences (CAAS-ASTIP-IVFCAAS)
文摘Phenylalanine ammonia-lyase (PAL), the first enzyme of phenylpropanoid pathway, is always encoded by multigene families in plants. In this study, using genome-wide searches, 13 PAL genes in cucumber (CsPAL1-13) and 13 PALs in melon (Cm- PALl-13) were identified. In the corresponding genomes, ten of these PAL genes were located in tandem in two clusters, while the others were widely dispersed in different chromosomes as a single copy. The protein sequences of CsPALs and CmPALs shared an overall high identity to each other. In our previous report, 12 PAL genes were identified in watermelon (CIPAL1-12). Thereby, a total of 38 cucurbit PAL members were included. Here, a comprehensive comparison of PAL gene families was performed among three cucurbit plants. The phylogenetic and syntenic analyses placed the cucurbit PALs as 11 CsPAL-CmPAL-CIPAL triples, of which ten triples were clustered into the dicot group, and the remaining one, CsPAL1-CmPAL8-CIPAL2, was grouped with gymnosperm PALs and might serve as an ancestor of cucurbit PALs. By comparing the syntenic relationships and gene structure of these PAL genes, the expansion of cucurbit PAL families might arise from a series of segmental and tandem duplications and intron insertion events. Furthermore, the expression profiling in different tissues suggested that different cucurbit PALs displayed divergent but overlapping expression profiles, and the CsPAL-CmPAL-CIPAL orthologs showed correlative expression patterns among three cucurbit plants. Taken together, this study provided an extensive description on the evolution and expression of cucurbit PAL gene families and might facilitate the further studies for elucidating the functions of PALs in cucurbit plants.
基金supported by the grants from the National Natural Science Foundation of China(31801712)the Key Research and Development Program of Guangdong Province,China(2018B020202006)+1 种基金the Agricultural Competitive Industry Discipline Team Building Project of Guangdong Academy of Agricultural Sciences(202103TD and 202105TD)the Development Program for Guangdong Province Modern Agricultural Science and Technology Innovation Alliance(2020KJ113)。
文摘Viral diseases are among the most critical damaging factors that impose a global threat to the cucurbit industry.China is the world’s leading country for the production and consumption of cucurbits.Guangdong,a province in southern China dominated by the tropical and subtropical climate,favors the survival of different plant viruses and their vectors.Five main cucurbit crops showing various disease symptoms were surveyed and collected to identify viruses infecting cucurbits in Guangdong during 2018–2020.In the field,the incidence ranged from 5-30%,or even 60-100% in the case of severely infected cucurbits.A total of 357 symptomatic samples were collected and subsequently screened for cucurbit viruses by small RNA deep sequencing and assembly(sRSA).Seventeen virus species belonging to 10 genera were identified in the five main cucurbit crops.The most common viruses were papaya ringspot virus(PRSV;Potyvirus),zucchini tigre mosaic virus(ZTMV;Potyvirus),zucchini yellow mosaic virus(ZYMV;Potyvirus),and watermelon silver mottle virus(WSMoV;Orthotospovirus),with infection rates of 24.4,19.0,17.1,and 14.3%,respectively.Notably,the most prevalent viruses were melon yellow spot orthotospovirus(MYSV)in cucumber,PRSV in squash,cucumber green mottle mosaic virus(CGMMV;Tobamovirus)in bottle gourd,WSMoV in white gourd,and ZYMV in luffa.Mixed infections were prevalent,and the types of mixed infections varied substantially in different cucurbit crops.Moreover,the full-length nucleotide sequences of watermelon green mottle mosaic virus(WGMMV),CGMMV,and watermelon virus A(WVA;Wamavirus)identified in bottle gourd were cloned and analyzed.This study is the first reporting WGMMV infecting bottle gourd in China mainland.In summary,the results demonstrate that in Guangdong,the most prevalent viruses belong to potyviruses,orthotospoviruses,and tobamoviruses groups.The findings will facilitate agricultural researchers and farmers to plan and implement effective disease control strategies aiming at timely detection and management of cucurbit-infecting viral pathogens.
基金supported by the Research Fund for the Doctoral Program of Higher Education of China(20091404110001)
文摘The insecticide cartap (CP) is non-fluorescent in aqueous solutions. This property makes its determination through direct fluorescent method difficult. In acidic medium and at room temperature, palmatine (PAL) can react with cucurbit[7]uril (CB[7]) to form stable complexes, and the fluorescence intensity of the complex is greatly enhanced. Significant quenching of the fluorescence intensity of the CB[7]-PAL complex was observed with the addition of cartap. Based on the significant quenching of the supramolecular complex fluorescence intensity, a new spectrofluorimetric method with high sensitivity and selectivity was developed to determine cartap in aqueous solution. The fluorescence quenching values (AF) showed good linear relationship with cartap concentrations from 0.009 to 2.4 ~tg mL-~ with a detection limit 0.0029 ~tg mE-x. The proposed method had been successfully applied to the determination of cartap residues in grain and vegetable with recoveries of 87.4-103%. In addition, the association constants of the complexes formed between the host and the guest were determined. The competing reaction and the supramolecular interaction mechanisms between the cartap and PAL as they fight for occupancy of the CB[7] cavity were studied using spectrofluorimetry, xH NMR and molecular modeling calculations.
基金supported by the Natural Science Foundation of Shanxi(No.2007011027).
文摘The inclusion interaction between berberine hydrochloride (BRH) and cucurbit[7] (CB[7]) has been studied by spectrofluorimetry. The result showed that CB[7] interaction with BRH to form a stable inclusion complex with an association constant of 9.57 × 10^4 L/mol and the fluorescence intensity of the complex was enhanced in 17 times higher than that of the studied drug itself. Based on the significant enhancement of fluorescence intensity of BRH in inclusion complex, a spetrofluorimetric method with high sensitivity and selectivity was developed for the determination of BRH in aqueous solution. The linear range of the method was 3.2- 2 × 10^3 ng/mL with a detection limit of 1.1 ng/mL. The proposed procedure could be applied successfully to determination of BRH remained in pharmaceutical dosage forms, spiked human plasma and urine with satisfactory results.
基金supported by the National Natural Science Foundation of China(No.20471056)
文摘A new cucurbit[6]uril bridsed binuclear complex {[Gd(H2O)6]2[Q6(H2O)]}C16·4H2O, where Q6 represents cucurbit[6]uril, has been synthesized and characterized by X-ray diffraction. The crystal structure shows that the complex has an extended cucurbit[6]uril-bridged structure consisting of two gadolinium(Ⅲ) ions, in which each gadolinium(Ⅲ) ion is coordinated with two neighboring carbonylic oxygen atoms of Q6 and six oxygen atoms of water molecules that leans toward one side of the portal. One disordered guest water molecule resides in the Q6 molecule cavity and occupies two different positions. Hydrogen bonds assemble the complcx to threedimensional supramolecular structure.
基金Department of Biotechnology(DBT),Govt.of India,for the fellowship and financial assistancefor his M.Sc.(Ag.)in Plant Biotechnolo gy research work(Grant No.CPBMB/CoH/DBT-HRD/12)。
文摘DNA barcoding is a supplementary tool in plant systematics,extensively used to resolve the species level controversies.This paper details the identification of DNA barcodes for seven species of Momordica,using the chloroplast gene mat K.Since the species M.cymbalaria has been confused as a member of the genus Luffa,26 accessions of Momordica belonging to seven Indian species and two accessions of Luffa acutangula were included in this study.Analysis of mat K sequences has yielded distinct barcodes in M.charantia var.charantia,M.subangulata subsp.renigera,M.cochinchinensis,M.balsamina,M.cymbalaria and also in Luffa acutangula.Evolutionary status of each species was reflected as nucleotide polymorphisms in each sequence.The wild species M.dioica and M.sahyadrica have yielded one barcode but failed to get differentiated.Further,this study provides conclusive proof that M.cymbalaria is a member of Momordica genus.The phylogram generated was successful to distinguish the monoecious species of this genus,M.charantia,M.balsamina and M.cymbalaria,from the dioecious species M.dioica,M.sahyadrica,M.subangulata subsp.renigera and M.cochinchinensis.Thus,mat K locus,by accumulating the evolutionary sequence variations,is proven efficient to differentiate the Momordica species and to reveal their relatedness.
基金Supported by the National Natural Science Foundation of China(No.20674045)the Natural Science Foundation of Shandong Province,China(No.ZR2011BM002)
文摘pH and temperature responsive copolymers PNAM4VBCB of N-isopropyl acrylamide(NAM) and complex pseudorotaxane monomer N 1-(4-vinylbenzyl)-1,4-diaminobutane dihydrochloride with cucurbit[6]uril(CB[6]) threaded(4VBCB) were prepared via free-radical polymerization in aqueous solution.The copolymers were characterized by 1 H NMR,Fourier transform infrared(FTIR) spectrometry,elemental analysis,and static light scattering.The thermodynamic properties of the copolymers were studied by thermogravimetric analysis(TGA),and the effects of pH and the concentration of the copolymer on the average hydrodynamic radius(R h) were studied by dynamic light scattering(DLS).In addition,the thermal sensitivities of the copolymers were studied by DLS and UV-Vis.The experiment data show that CB[6] beads are localized on 1,4-diaminobutane units in the side chains of the copolymer.TGA data show that thermal stability of the copolymers increases with the adding of CB[6] threaded because of the enhanced rigidity and the bulky steric hindrance of 4VBCB in the side chain of PNAM4VBCB.DLS data show that the average hydrodynamic radius of copolymer increases with the increase of the copolymer concentration and has a jump with adjusting pH due to the existing of the small size CB[6] dethreaded from the copolymer with increasing pH.Both pH and electrical conductivity curves of the solution of PNAM4VBCB-4 have a jump because CB[6] could dethread from the copolymers with the addition of NaOH.In addition,the copolymers have thermal sensitivity and their phase-change temperatures could be controlled by adjusting the molar ratio of NAM to 4VBCB in the copolymers.
基金the Japanese Government(Monbukagakusho)Scholarship.
文摘Cucurbitaceae family contains important economic and medical crops, they can be divided into two categories according to the worldwide consumption, use, and production. The Cucurbit Popular Crops (CuPoC) are comprised of cucumber, the Cucurbita group (pumpkin and squash), melon and watermelon. On the other hand, Neglected and Underutilized Cucurbit Species (NUCuS) group has been used as food sources, medicinal properties and elements in the elaboration of different types of items. The NUCuS is represented in this review work by bitter gourd, bottle gourd, chayote, ridge gourd, and snake gourd, which are recognized mainly in Asia. The center of origin of the majority of NUCuS was proposed to be in the Old World. In contrast, the origin of chayote or Sechiumedule (Jacq.) Sw. was suggested in the New World, precisely in Mesoamerican region based on linguistic uses and distribution of wild relatives. The environmental factors along with artificial selection, production systems and traditional knowledge have been influenced the evolutionary history of NUCuS, Infraspecific variation of chayote has been reported in Mexico over-described varietal groups. These descriptors were determined based on biochemical and morpho-structural traits;however, cytogenetic analyses are scarce. Specifically, chromosome and nuclear content analyses are important to support botanical groups, analyze artificial selection history, developing breeding and conservation programs. The present review paper discusses agronomic and evolutionary importance based on cytological evidence in NUCuS, mainly in the prominent chayote;with the perspective to prompt breeding, conservation, cytology, structural and functional genomics research for its sustainable utilization.
基金supported by the Royal Society(No.RGS\R2\202203Lan_4824933)the Engineering and Physical Sciences Research Council(Nos.EP/N509577/1,EP/T517793/1,and EP/S03305X/1).
文摘Enhancing the proton conductivity of proton exchange membranes(PEMs)is essential to expand the applications of proton exchange membrane fuel cells(PEMFCs).Inspired by the proton conduction mechanism of bacteriorhodopsin,cucurbit[n]urils(CB[n],where n is the number of glycoluril units,n=6,7,or 8)are introduced into sulfonated poly(ether ether ketone)(SPEEK)matrix to fabricate hybrid PEMs,employing a nature-inspired chemical engineering(NICE)methodology.The carbonyl groups of CB[n]act as proton-conducting sites,while the host–guest interaction between CB[n]and water molecules offers extra protonconducting pathways.Additionally,the molecular size of CB[n]aids in their dispersion within the SPEEK matrix,effectively bridging the unconnected proton-conducting sulfonic group domains within the SPEEK membrane.Consequently,all hybrid membranes exhibit significantly enhanced proton conductivity.Notably,the SPEEK membrane incorporating 1 wt.%CB[8](CB[8]/SPEEK-1%)demonstrates the highest proton conductivity of 198.0 mS·cm^(−1) at 60°C and 100%relative humidity(RH),which is 228%greater than that of the pure SPEEK membrane under the same conditions.Moreover,hybrid membranes exhibit superior fuel cell performance.The CB[8]/SPEEK-1%membrane achieves a maximum power density of 214 mW·cm^(−2),representing a 140%improvement over the pure SPEEK membrane(89 mW·cm^(−2))at 50°C and 100%RH.These findings serve as a foundation for constructing continuous proton-conducting pathways within membranes by utilizing supramolecular macrocycles as fuel cell electrolytes and in other applications.
文摘Fluorescent poly(N-isopropylacrylamide-co-Nile blue)(pNIPAm-co-NB)microgels were synthesized that exhibited fluorescence intensity changes in a water temperature-dependent fashion.NB is well known to exhibit fluorescence intensity that depends on the hydrophobicity of the environment,while pNIPAm-based microgels are well known to transition from swollen(hydrophilic)to collapsed(relatively hydrophobic)at temperatures greater than 32℃;hence,we attribute the above behavior to the hydrophobicity changes of the microgels with increasing temperature.This phenomenon is ultimately due to NB dimers(relatively quenched fluorescence)being broken in the hydrophobic environment of the microgels leading to relatively enhanced fluorescence.We went on to show that the introduction of cucurbit[7]uril(CB[7])into the pNIPAm-co-NB microgels enhanced their fluorescence allowing them to be used for polyamine(e.g.,spermine[SPM])detection.Specifically,CB[7]forms a host–guest interaction with NB in the microgels,which prevents NB dimerization and enhances their fluorescence.When SPM is present,it forms a host–guest complex that is favored over the CB[7]-NB host–guest interaction,which frees the NB for dimerization and leads to fluorescence quenching.As a result,we could generate an SPM sensor capable of SPM detection down to~0.5µmol/L in complicated matrixes such as serum and urine.
基金supported by a grant from the Key Research and Development Program of Hainan Province(ZDYF2021XDNY166)the Key Science and Technology Program for Agricultural(Vegetable)New Variety Breeding of Zhejiang Province(2021C02065)the Earmarked Fund for Modern Agro-Industry Technology Research System of China(CARS-26-17).
文摘Tomato leaf curl New Delhi virus(ToLCNDV),a bipartite begomovirus,was first reported to infect tomato and has recently spread rapidly as an emerging disease to Cucurbitaceae crops.To date,the virus has been reported to infect more than 11 cucurbit crops,in 16 countries and regions,causing severe yield losses.In autumn 2022,ToLCNDV was first isolated from cucurbit plants in Southeastern coastal areas of China.Phylogenetic analysis established that these isolates belong to the Asian ToLCNDV clade,and shared high nucleotide identity and closest genetic relationship with the DNA-A sequence from the Chinese tomato-infecting ToLCNDV isolate(Accession no.OP356207)and the tomato New Delhi ToLCNDV-Severe isolate(Accession no.HM159454).In this review,we summarize the occurrence and distribution,host range,detection and diagnosis,control strategies,and genetic resistance of ToLCNDV in the Cucurbitaceae.We then summarize pathways that could be undertaken to improve our understanding of this emerging disease,with the objective to develop ToLCNDV-resistant cucurbit cultivars.
基金supported by the National Natural Science Foundation of China(22025503,22220102004)the Shanghai Municipal Science and Technology Major Project(2018SHZDZX03)+3 种基金the Fundamental Research Funds for the Central Universitiesthe Programme of Introducing Talents of Discipline to Universities(B16017)the Science and Technology Commission of Shanghai Municipality(21JC1401700)the Starry Night Science Fund of Zhejiang University Shanghai Institute for Advanced Study(SN-ZJU-SIAS-006)。
文摘Programming microscopic assembly mode to control macroscopic property is an attractive research objective.In particular,controlling molecular assembly to control fluorescence is of considerable interest for developing smart fluorescent materials.Herein,a color-tunable supramolecular emissive system was developed based on cucurbit[8]uril mediated host-guest assembly.Chemical designing for the molecular structures with minimized change resulted in different assembly modes and hence generating distinctive fluorescence,including green,yellow and orange with the addition of cucurbit[n]uril.Taking advantage of this feature,the advanced information encryption material(4D code)with multiple encryption levels and time-dependent encryption feature was developed.Such a code was dynamic on time scale,generating a series of 3D codes with time.The encrypted information only can be recognized by integrating time-coursed codes.This work provides a new insight for designing intelligent fluorescent materials for information encryption with high level of security.
基金We thank Top-Notch Talents Program of Henan Agricultural University(No.30501049)Project supported by the Science and Technology Department of Henan Province(No.212102310332)the Merit Funding for the Oversea Staff of Henan Province for financial support.
文摘Photoresponsive supramolecular systems have merited extensive attention for their applications in materials science and life science.Here,we synthesized a water-soluble stiff-stilbene molecular photoswitch,exhibiting outstanding photoisomerization reaction between its(E)-and(Z)-configurations upon irradiation at distinct light.The photoswitch can assemble with cucurbit[7]uril(CB[7])to form a superior fluorescent supramolecular complex(compared to the only guest)with excellent water solubility,which manifested dramatic photoluminescence enhancement caused by restriction of intramolecular rotation and remained good photochromic characteristics.Furthermore,introduction of CB[7]influence photoreaction quantum yield(Φ)of the stiff-stilbene,leading to reduction ofΦ_(E→Z) and increase ofΦ_(Z→E) of the stiff-stilbene.Importantly,the photoadjustable supramolecular assembly can act as a fluorescence switch,and the phototunable guest further selectively modulate G-quadruplex structure of Tel22 upon light irradiation or with addition of CB[7].The study provides a new simple way for accurately regulating photochromic properties of molecular switches and developing smart materials with potential applications in controlled modulation of G-quadruplex,targeted biological imaging and so on.
基金supported by the Innovation Program for Highlevel Talents of Guizhou Province (No. 2016-5657)the University of Hull for support。
文摘The binding interactions between 4-aminopyridine(4-AP) and a series of cucurbit[n]urils(Q[5], Q[6],TMe Q[6], Q[7], Q[8]) have been studied using1H NMR spectroscopy, UV–vis absorption spectroscopy,isothermal titration calorimetry(ITC) and X-ray crystallography. The data indicates that the Q[5]@4-AP complex exhibits exo binding, which is not observed in the other four host-guest complexes. Furthermore,X-ray crystallography clearly reveals how the Q[n]s bind with 4-AP to form complexes, for example Q[5]forms an outer-surface complex, whilst Q[6], TMe Q[6] and Q[7] formed 1:1 host and guest type complexes, and Q[8] formed a stable 1:2 ternary complex due to its large cavity, which can accommodate two 4-AP molecules.
基金the financial support from the National Key R&D Program of China(Nos.2017YFA0206802,2018YFA0704502)the National Natural Science Foundation of China(NSFC,No.22033008)Fujian Science&Technology Innovation Laboratory for Optoelectronic Information of China(No.2021ZZ103)。
文摘Developing efficient and stable electrocatalyst to hydrogen evolution reaction adaptable for electrolytes with different p H is a big challenge.In this work,a hierarchically structured ternary nanohybrid composed of flower-like Ru nanoparticles,rigid macrocyclic cucurbit[6]uril(CB[6])and carboxylated multiwalled carbon nanotubes(MWCNTs)was successfully prepared by chemical wet method.Benefited by the structural merits of flower-like Ru nanoparticles exposed abundant active sites supported by the MWCNTs holding superior mass transport and electrons transfer ability as well as the existence of CB[6],the obtained catalyst exhibited outstanding HER activities with overpotentials of 27,37 and 70 m V at-10 m A/cm^(2) in alkaline,acidic,and neutral electrolytes,respectively.Under the same electrocatalytic operation conditions,the HER performance is comparable or superior to commercial Pt/C catalyst(47,27and 49 m V).Besides,chronopotentiometric and accelerated stability test also revealed its extraordinary stability,which could be further employed for electrocatalytic procedure in a broad pH range.
基金supported in part by grants from the National Natural Science Foundation of China (No. 21871108)the Program for Innovative Teams of Outstanding Young and Middle-Aged Researchers in the Higher Education Institutions of Hubei Province(No. T201702)。
文摘In this paper, cucurbit[7]uril(CB[7])-mediated three-dimensional gold nanoassemblies were successfully prepared to increase the loaded amount of CB[7] and enhance the electrochemical detection of amino acids. Particle sizes of gold nanoparticles(Au NPs) significantly affect stability and detection sensitivity of nanoassemblies. The volume of gold nanoassemblies first increased and then decreased with the increase of CB[7] concentration. The 3D gold nanoassemblies composed of 16 nm Au NPs and 100 μmol/L CB[7]had excellent stability and maximum volume, exhibiting more sensitive detection for a variety of amino acids. And the detection limits of aromatic amino acids are lower in virtue of the higher binding constant between aromatic amino acids and CB[7]. This study will develop and deepen our understanding of molecular recognition in amino acids detection.
基金supported by the National Natural Science Foundation of China(No.21861011)the Innovation Program for Highlevel Talents of Guizhou Province(No.2016-5657)+1 种基金the Science and Technology Fund of Guizhou Province(No.[2020]-1Y046)University of Hull for support。
文摘The macrocyclic family comprising pillar[n]arenes and cucurbit[n]urils have received much attention recently. However, studies on the construction of supramolecular complexes formed directly with derivatized pillar[n]arenes and cucurbit[n]urils are scant. Given the interest in such systems, herein we have synthesized a new type of naphthalene-derivatized pillar[n]arene NTP5 and selected Q[10] as the host molecule. The 4-[2-(1-naphthalenyl)ethenyl]pyridine of NTP5 is encapsulated by Q[10] and formed a hostguest complex in water-acetic acid(1:1) solution accompanied by enhanced fluorescence, which changed the morphology of NTP5 from a sphere to a porous form. In addition, the fluorescence of Q[10]-NTP5 can be quenched by the addition of the highly toxic pesticide paraquat(PQ), and the mechanism was shown to be the formation of a new charge transfer ternary system of Q[10]-NTP5-PQ. This work provides new ideas for the contribution of supramolecular assemblies based on derivatized pillar[n]arenes and their combination with cucurbit[n]urils and reveals their potential applications.
基金National Natural Science Foundation of China(No.21921003)for financial support。
文摘Photodynamic therapy(PDT)agents may accumulate in skin and cause severe skin cytotoxicity.We report a pro-guest-based supramolecular strategy to selectively activate PDT in the reactive oxygen specie(ROS)overexpressed microenvironment,which is often existing in tumor and inflammatory tissues.PDT agents methylene blue(MB)and basic blue 17(BB17)are used as model drugs.When encapsulated by acyclic cucurbit[n]uril(CB[n]),the efficacy of PDT agents is significantly inhibited.By contrast,in the presence of ROS(H_(2)O_(2))and pro-guest,PDT agents are displaced and reactivated to show a dramatically enhanced PDT efficacy in cells.