Evaluation of the Antibacterial and Antifungal Capacity of Nanoemulsions Loaded with Synthetic Chalcone Derivatives Di-Benzyl Cinnamaldehyde and Benzyl 4-Aminochalcone

With the increase in antimicrobial resistance,it has become necessary to explore alternative approaches for combating and preventing diseases.DB-cinnamaldehyde(CNM)and Benzyl4-amino(B4AM)are bioactive compounds derived from chalcones but with restricted solubility in aqueous media.Nanoemulsions can enhance the solubility of compounds and can be a promising alternative in the development of novel antimicrobials,with reduced side effects and prolonged release.The objective of this study was to evaluate the stability of oil-in-water nanoemulsions loaded with two distinct types of chalcones at two different dosages,to propose a stable formulation with antimicrobial properties.Results showed that nanoemulsions presented high encapsulation efficiency,low polydispersity index(PDI)and particle size below 200 nm,indicating that emulsification was a suitable method for nanoemulsion preparation.Nanoemulsions with higher dosages exhibited significant antimicrobial effects when compared to free chalcones and positive controls.Notably,B4AM nanoemulsions at higher dosages showed expressive activity against Salmonella minnesota,with a 420%greater inhibitory response compared to the free form and showing equivalence to the positive control.CNM nanoemulsions showed excellent inhibitory activity at the highest dosage,equivalent to the positive control against S.minnesota and Staphylococcus aureus.The greater number of conjugated bonds in CNM increased the antimicrobial activity in comparison with B4AM,and the formation of nanometric domains enhanced the bioavailability,being a promising alternative for antimicrobial applications.

Cloning of Tap Ⅱ Chalcone Isomerases(CHI1 A) Gene and Construction of Lactococcus Lactis Expression Vector

[Objective]The aim was to clone TapⅡchalcone isomerases（CHI1 A） from soybean specially and construct expression vector of PNZ8149-CHI1 A,and then transform it into Lactococcus Lactis NICE systers.[Method]Chalcone isomerases（CHI1 A） was cloned by RTPCR method,and it was sequenced after cloning into pMD18-T vectors,and recombined to expression vector PNZ8149-CHI1 A,then it was transformed into Lactococcus Lactis NZ3900[Result]The sequencing results indicated that the cloned fragment of CHI1 A contained 670 nucleotides,and shared a sequence homology of 92% with that from Genbank accession number AF595413（CHI1 A）.CHI1 A was transformed into NICE expression system successfully by identification of PCR and digestion.[Conclusion]The foundation of using the microorganism fermentation method to produce flavonoids was laid by construction of efficient induction expression vector with chalcone isomerases CHI1 A.

Molecular Composition and Evolution of the Chalcone Synthase (CHS) Gene Family in Five Species of Camellia (Theaceae)

The molecular composition and evolution of the chalcone synthase (CHS) gene family from five species in Camellia (Theaceae) are explored in this study. Sixteen CHS exon 2 from four Camellia species were amplified from total DNA by PCR method. Three sequences of the fifth species in Camellia and two sequences of Glycine max as the designated outgroups were obtained from GenBank. Our results indicated that CHS gene family in Camellia was differentiated to three subfamilies (A, B, C) during the evolutionary history with six groups (A1, A2, A3, BI, B2, C). Among them, only group A2 was possessed by all five species in this study. However, the other five groups were detected only in some species of the plants studied. All members of CHS gene family in this study had high sequence similarity, more than 90% among the members in the same subfamily and more than 78% among different subfamilies at nucleotide level., According to the estimated components of amino acids, the function of CHS genes in Camellia had been diverged. The nucleotide substitutions of the different groups were not identical. Based on phylogenetic analyse inferred from sequences of CHS genes and their deduced amino acid sequences, we concluded that the CHS genes with new function in this genus were evolved either by mutations on several important sites or by accumulation of the mutations after the gene duplication. A further analysis showed that the diversification of CHS genes in Camellia still occurred recently, and the evolutionary models were different to some extant among different species. So we assumed that the different evolutionary models resulted from the impacts of variable environmental elements after the events of speciation.

Synthesis of a New Series of Chalcone Derivatives and Their Antifungal Activities

To study the antifungal effect of chalcone derivatives. Methods Sixteenchalcone derivatives were synthesized and confirmed by ~1H NMR and IR spectra, and tested forantifungal activity against four common pathogenic fungi. Their structure-activity relationship isdiscussed. Results Among 16 title compounds, there were 5 new compounds, which have not beenreported before. The preliminary antifungal test showed that all title compounds exhibitedantifungal activities to a certain extent. The activity of compound 8 against Trichophyton rubrumhad a potency equal to that of fluconazole, with a MIC of 4 μg·mL^(-1) . Conclusion Sixteenchalcones were prepared and their antifungal activities against four common pathogenic fungi invitro were examined. Some of them exhibited antifungal activities to a certain extent.

(E)-2-Benzylidenecycloalkanones XII.*Kinetic Measurement of Bovine and Human Serum Albumine Interaction with Selected Chalcones and Their Cyclic Chalcone Analogues by UV Spectrophotometry

UV-VIS spectroscopic investigations of interaction of bovine and human serum albumin with selected chalcones (1) and their cyclic chalcone analogues: (E)-2-(4’-X-benzylidene-1-tetralones (3), benzosuberones (4) with dimethylamino and methoxy substituents and (E)-2-(2’,4’-dimethox- ybenzylidene)-1-indanone (2) were performed in polar respiration medium. Absorption maxima of the tested compounds were investigated in the presence of bovine and human serum albumin at the 0, 10, 30 and 60 minute timepoints of the interaction. The absorbance of all studied compounds in the presence of proteins decreased after one hour of the reaction. Molecule 4a showed the strongest and fastest kinet initial interaction with both albumins.

A Facile Total Synthesis of 2-Geranyl-2',3,4',4-tetrahydroxydihydrochalcone with Highly 5-Lipoxygenase Inhibiting Activity

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Chalcone analogue as potent anti-malarial compounds against Plasmodium falciparum:Synthesis,biological evaluation,and docking simulation study

To investigate in vitro antimalarial activity of chalcone derivative compounds against Plasmodium falciparum 3D7 (Pf3D7) strain and in silico antimalarial activity.MethodsSynthesis of the chalcone derivatives was conducted via Claisen-Schmidt method using NaOH 60% base as catalyst. An in vitro antimalarial activity assay was carried out according to the Rieckmann method against the chloroquine-sensitive Pf3D7 strain. Molecular docking studies of the prepared compounds were performed using Discovery Studio 3.1 (Accelrys, Inc., San Diego, USA) software to dihydrofolate reductases-thymidylate synthase (PfDHFR-TS) protein with Protein Data Bank ID of 1J3I.pdb (sensitive-protein) and ID: 4DP3.pdb (resistance-protein).ResultsThis work has successfully synthesized seven chalcone derivatives with a great antimalarial activity. It has been revealed that allyloxy, hydroxy and alkoxy functional groups could increase the antimalarial activity of the chalcone derivatives. The best antimalarial activity of the prepared compounds was possessed by 3b with an IC50 value of 0.59 μM and categorized as an excellent antiplasmodial. Molecular docking studies of 3b showed binding interaction with the amino acid residues such as Ala16, Ile164, Phe58, Tyr170 of the 1J3I.pdb protein and also Ala16, Phe58, Ile112, Met55 of the 4DP3.pdb protein.ConclusionsAn in vitro antimalarial assay of the prepared chalcone derivative (3a-g) showed an excellent and good antiplasmodial activity against the chloroquine-sensitive Pf3D7 strain. In silico antimalarial studies revealed that 3a-g made binding interaction with both sensitive-protein (1J3I.pdb) and resistance-protein (4DP3.pdb), which means that they were both active against chloroquine-sensitive and resistant plasmodium strain.

A new chalcone from the aerial roots of Ficus microcarpa

A new flavonoid with chalcone skeleton was isolated from the dried aerial roots of Ficus microcarpa. The structure of the compound was elucidated on the basis of spectral methods including 1D and 2D NMR. The new compound showed weak inhibitory effect on nitric oxide production and cytotoxicity against K562 and PC3 cells.

Effect of Angelica keiskei chalcone on the expression of apoptosis-regulating proteins of mice hepatocarcinoma cells

Objective: The aim of our study was to investigate the effect of Angelica keiskei chalcone (AC) on the expression of Caspase-3 and Bax in mice hepatocarcinoma cells. Methods: Fifty mice inoculated hepatocarcinoma 22 cells were divided into five groups, 10 mice per group. Mice were given 5, 20, 40 mg/kg AC daily by mouth in low, middle and high dose groups respectively. Saline were given to the tumor control group by mouth. Twenty mg/kg cytoxan (CTX) by injection every other day were given to the positive control group. Ten days later, all mice were sacrificed. The levels of the Caspase-3 and Bax protein expression were measured by immunohistochemistry method and the proliferation activity of hepatocarcinoma cells was determined by MTT assay. Results: The expression level of Caspase-3 and Bax protein in tumor control group were 5.00% and 4.68%, respectively, and those of the high-dose group were 38.52% and 35.76%. The differences between two groups were significant (P < 0.05). The cell proliferation activity of tumor control group and high-dose group were 1.135 ± 0.032 and 0.716 ± 0.018. The difference was significant (P < 0.05). Conclusion: AC can increase the expression of Caspase-3 and Bax protein, and inhibit the proliferative activity of mice hepatocarcinoma cells.

cDNA Cloning and Expression Analysis of the Chalcone Synthases (CHS) in <i>Osmanthus fragrans</i>

In the flavonoid biosynthesis pathway, Chalcone synthase (CHS) is involved in the formation of the pigment and has been shown to be a rate-limiting enzyme for the synthesis of flavonoids. In this study, a PCR approach was used to clone a Chalcone synthases cDNA from flower of sweet osmanthus “Chenghong Dangui” and it was designated as OfCHS (O. fragrans, CHS). The cDNA was 1383 bp long and a coding sequence (CDS) of 1173 bp encoding a polypeptide of 391 amino acids with an estimated molecular mass of 39.9 kDa. The theoretical isoelectric point was 6.23. Phylogenetic analysis demonstrated that OfCHS clustered with Olea europaea, Solenostemon scutellarioides, Perilla frutescens, Antirrhinum majus and Digitalis lanata. We also detected the expression of OfCHS in different tissues in “Dangui” and in two cultivars with varied coloration, “Zi Yingui” and “Chenghong Dangui” at different floral stages using quantitative real-time PCR. We observed that OfCHS transcript was higher in leaves than in petals in “Dangui”. The transcripts of OfCHS in “Zi Yingui” petals were higher than those in “Dangui” at three stages especially at xianyan stage and there was no significant difference between the two cultivars in the full flowering stage. “Chenghong Dangui” has a relatively high anthocyanin content compared to “Zi Yingui”. The relative amount of anthocyanin of “Chenghong Dangui” initially increases, and then decreases during the bloom period. However, the expression of CHS is the highest at the initial flowering stage. These data suggest that the OfCHS does not play a key role in the accumulation of total flavonoid in this cultivar. These data could contribute to explain the different accumulation of flavonoids in petals of the two cultivars.

Ionic liquid catalyzed solvent-free synthesis of chalcone and its derivatives under mild conditions

An ionic liquid(IL)catalyzed solvent-free process was developed for the direct synthesis of chalcone and its derivatives by using substituted acetophenones and benzaldehydes via aldol reaction under mild conditions.A series of acidic and basic ILs were selected and screened.The influences of cations and reaction conditions on product yield and selectivity were systematically investigated.The[Bmim]OH was identified as the optimal IL,with the highest yield and selectivity reaching up to 96.7% and 100%,respectively.A reaction mechanism-based kinetic model was established and regressed with experimental data,revealing the β-Hydroxylketone dehydrolysis with activation barrier of 37.8 kJ·mol^(-1) was observed as the ratecontrolling step.

Isolation and expression analysis of NtCHS6, a new chalcone synthase gene from Nicotiana tabacum

Chalcone synthases （CHS, EC 2.3.1.74） are key enzymes that catalyze the first committed step in flavonoid biosynthesis. In this study, we isolated a chalcone synthase, named NtCHS6, from Nicotiana tabacum. This synthase shared high homology with the NSCHSL （Y14507） gene and contained most of the conserved active sites that are in CHS proteins. The phylogenetic analysis suggested that NtCHS6 protein shared a large genetic distance with other Solanaceae CHS proteins and was the most closely-related to an uncharacterized CHS from Solanum lycopersicum. The expression analysis indicated that NtCHS6 was abundantly expressed in leaves, especially in mature leaves. By scrutinizing its upstream promoter sequences, multiple cis-regulatory elements involved in light and drought responsive were detected. Furthermore, NtCHS6 expression decreased significantly under dark treatment and increased significantly under drought stress suggested that NtCHS6 expression exhibited both light responsiveness and drought responsiveness, and important roles in ultraviolet protection and drought tolerance. Our results might play

The novel chalcone analog L2H17 protects retinal ganglion cells from oxidative stress-induced apoptosis

Chalcone is a plant metabolite widely found in fruits,vegetables,spices and tea,and has anti-tumor,anti-inflammation,immunomodulation,antibacterial and anti-oxidation activities,as well as many other pharmacological and biological effects.Our team has shown that its analogs have antioxidant activity,and oxidative stress is a pathological hallmark of retinal ischemia/reperfusion injury that can lead to retinal damage and visual loss.This investigation aims to identify a chalcone that protects retinal ganglion cells in vitro from the effects of oxidative stress and examine its mechanism.Rat retinal ganglion cell-5 cells were pretreated with chalcones and then exposed to tert-butyl hydroperoxide that causes oxidative damage.Controls received dimethyl sulfoxide only or tert-butyl hydroperoxide in dimethyl sulfoxide.Only（E）-3,4-dihydroxy-2′-methylether ketone（L2 H17）,of the five chalcone analogs,markedly increased the survival rate of oxidatively injured RGC-5 cells.Thus,subsequent experiments only analyzed the results of the L2 H17 intervention.Cell viability and apoptosis were measured.Intracellular superoxide dismutase and reactive oxygen species levels were used to assess induced oxidative stress.The mechanism of action by L2 H17 was explored by measuring the ER stress/UPR pathway and the expression and localization of Nrf2.All results demonstrated that L2 H17 could reduce the apoptosis of oxidatively injured cells,inhibit caspase-3 activity,increase Bcl-2 expression,decrease Bad expression,increase the activity of superoxide dismutase,inhibit the production of reactive oxygen species,increase Nrf2 immunoreactivity,and reduce the activating transcription factor 4,phospho-eukaryotic initiation factor 2 and CHOP expression.L2 H17 protects retinal ganglion cells induced by oxidative stress by regulating Nrf2,which indicates that it has the potential to become a drug for retinal ischemia/reperfusion.

Two new chalcones from Fordia cauliflora

Two new chalcones,β,2′,4′,5′-tetramethoxychalcone 1,andβ,2′,5′-trimethoxyfurano[4″,5″：3′,4′]-chalcone 2 were obtainedfrom an ethyl acetate-soluble fraction of ethanol extract of the stem of Fordia cauliflora.Their chemical structures were determinedby analysis of spectroscopic evidences.

A Solid Phase Synthesis of Chalcones by Claisen-Schmidt Condensations

In order to accelerate the development of relatively inexpensive antimalarials that are effective against chloroquine-resistant strains of Plasmodium falciparum, a methodology for the solid phase synthesis of chalcone (1, 3-diphenyl-2-propen-1-one) analogues in reasonably high yields has been developed.

New flavan and unusual chalcone glycosides from Drypetes parvifolia

Two new compounds 7-hydroxy-5-O-（β-D-glucopyranoside） flavan （1） and （Z）-4＇,6＇-dihydroxy-2＇-O-（β-D-glucopyranoside） chalcone （2）, along with eight known compounds, were isolated from the stem bark of Drypetes parvifolia （Euphorbiaceae）. Their structures were established on the basis of spectroscopic analysis and chemical evidence.

Efficiency of Chalcone Compounds Inhibitors for Acid Corrosion of Al and Al-3.5Mg Alloy

Corrosion inhibition of Al and Al-3.5Mg alloy by organic compounds, namely chalcones in hydrochloric acid solutions has been investigated by rapid polarization technique and weight loss method. Polarization measurements show that, the inhibitors act cathodically both in case of Al and Al-3.5Mg alloy. It was found from the weight loss measurements that, the inhibition efficiency depends on the substituent in the chalcone compound. The relative inhibitive efficiency of these compounds has been explained on the basis of structure dependent electron donor properties of the inhibitors and the metal inhibitor interaction on the surface. The inhibition efficiency ranges from 16 to 64% for Al and from 30% to 91% for Al-3.5Mg alloy

PHOTOPOLYMERIZATION INITIATED BY DIMETHYLAMINOCHALCONE/DIPHENYLIODONIUM SALT COMBINATION SYSTEM SENSITIVE TO VISIBLE LIGHT

Several dimethylamino-substituted chalcone (i .e. dimethylaminobenzal acetophenone) (DBA) derivatives with intramolecular charge transfer transition character were used as visible light sensitizers for radical photopolymerization initiated by iodonium salt (DPIO). Initiating radical species is produced from DBA sensitized photolysis of DPIO through the single electron transfer, accompanying the bleaching of DBA, The activity of DBA decreases as a function of substituent attached to phenyl ring in the order: DBA-2 (OCH_3) >DBA-1(H)> DBA-3 (Cl). The kinetic study on photopolymerization of MMA was carried out in CH_3CN solution at 30 ℃ by dilatometry. The polymerization rate was determined to be proportional to the concentration with exponents of 0.42, 0.25 and 0.86 for DPIO, DBA-1 and MMA, respectively.

Structural features of substituted triazole-linked chalcone derivatives as antimalarial activities against D_(10) strains of Plasmodium falciparum: A QSAR approach

A quantitative structure–activity relationship(QSAR) was performed to analyze antimalarial activities against the D10 strains of Plasmodium falciparum of triazole-linked chalcone and dienone hybrid derivatives using partial least squares regression coupled with stepwise forward–backward variable selection method. QSAR analyses were performed on the available IC50 D10 strains of Plasmodium falciparum data based on theoretical molecular descriptors. The QSAR model developed gave good predictive correlation coefficient(r2) of 0.8994, significant cross validated correlation coefficient(q2) of 0.7689, r2 for external test set)(2predr of 0.8256, coefficient of correlation of predicted data set)(2sepred,r of 0.3276. The model shows that antimalarial activity is greatly affected by donor and electron-withdrawing substituents. The study implicates that chalcone and dienone rings should have strong donor and electron-withdrawing substituents as they increase the activity of chalcone. Results show that the predictive ability of the model is satisfactory, and it can be used for designing similar group of antimalarial compounds. The findings derived from this analysis along with other molecular modeling studies will be helpful in designing of the new potent antimalarial activity of clinical utility.

A novel chalcone derivative from Onychium japonicum

A novel chalcone derivative was isolated from Onychium japonicum and its structure was elucidated by spectroscopic methods.The isolated compound showed cytotoxic activity against the human carcinoma cell lines Hela and BEL-7402 in vitro.