DNA G-Quadruplexes as Targets for Natural Product Drug Discovery

DNA guanine(G)-quadruplexes(G4s)are unique secondary structures formed by two or more stacked Gtetrads in G-rich DNA sequences.These structures have been found to play a crucial role in highly transcribed genes,especially in cancer-related oncogenes,making them attractive targets for cancer therapeutics.Significantly,targeting oncogene promoter G4 structures has emerged as a promising strategy to address the challenge of undruggable and drug-resistant proteins,such as MYC,BCL2,KRAS,and EGFR.Natural products have long been an important source of drug discovery,particularly in the fields of cancer and infectious diseases.Noteworthy progress has recently been made in the discovery of naturally occurring DNA G4-targeting drugs.Numerous DNA G4s,such as MYC-G4,BCL2-G4,KRAS-G4,PDGFR-b-G4,VEGF-G4,and telomeric-G4,have been identified as potential targets of natural products,including berberine,telomestatin,quindoline,sanguinarine,isaindigotone,and many others.Herein,we summarize and evaluate recent advancements in natural and nature-derived DNA G4 binders,focusing on understanding the structural recognition of DNA G4s by small molecules derived from nature.We also discuss the challenges and opportunities associated with developing drugs that target DNA G4s.

The Clausena lansium genome provides new insights into alkaloid diversity and the evolution of the methyltransferase family

Wampee(Clausena lansium)is an important evergreen fruit tree native to southern China that has a long history of use for medicinal purposes.Here,a chromosome-level genome of C.lansium was constructed with a genome size of 282.9 Mb and scaffold N50 of 30.75 Mb.The assembled genome contains 48.70%repetitive elements and 24,381 protein-coding genes.Comparative genomic analysis showed that C.lansium diverged from Aurantioideae 15.91-24.95 million years ago.Additionally,some expansive and specific gene families related to methyltransferase activity and S-adenosylmethionine-dependent methyltransferase activity were also identified.Further analysis indicated that N-methyltransferase(NMT)is mainly involved in alkaloid biosynthesis and O-methyltransferase(OMT)participates in the regulation of coumarin accumulation in wampee.This suggested that wampee's richness in alkaloids and coumarins might be due to the gene expansions of NMT and OMT.The tandem repeat event was one of the major reasons for the NMT expansion.Hence,the reference genome of C.lansium will facilitate the identification of some useful medicinal compounds from wampee resources and reveal their biosynthetic pathways.

Identification and Molecular Characterization of the Alkaloid Biosynthesis Gene Family in Dendrobium catenatum

As one of the main active components of Dendrobium catenatum, alkaloids have high medicinal value. The physicochemicalproperties, conserved domains and motifs, phylogenetic analysis, and cis-acting elements of the genefamily members in the alkaloid biosynthesis pathway of D. catenatum were analyzed by bioinformatics, and theexpression of the genes in different years and tissues was analyzed by qRT-PCR. There are 16 gene families,including 25 genes, in the D. catenatum alkaloid biosynthesis pathway. The analysis of conserved domains andmotifs showed that the types, quantities, and orders of domains and motifs were similar among members ofthe same family, but there were significant differences among families. Phylogenetic analysis indicated that thegene family members showed some evolutionary conservation. Cis-acting element analysis revealed that therewere a large number of light-responsive elements and MYB (v-myb avian myeloblastosis viral oncogene homolog)-related elements in these genes. qRT-PCR showed that expressions of gene family members involved in alkaloidsynthesis were different in different years and tissues of D. catenatum. This study provides a theoretical basisfor further exploration of the regulatory mechanisms of these genes in the alkaloid biosynthesis of D. catenatum.

Study of the Effectiveness of Papaver Sp. Alkaloids as Future Therapeutic Alternatives against Enterococcus Sp. Causing Hospital-Acquired Septicemic Infections

Background and Objective: In recent years, control of Enterococcus sp. It has been proven in the local medical environment to be a cause of acquired septicemia in various age groups, and medical instruments are considered an effective means of transmitting enterococcal septicemia, and catheters are at the forefront in terms of danger. Based on this risk, this study aimed to monitor the spread of Enterococcus sp., which causes blood poisoning acquired from catheters, and to compare its response to antibiotics with that of those isolated from clinical samples in children, as a first study locally. The effectiveness of alkaloids of different types of Papaver sp. In Syrian plants, they were tested against infection with this bacteria. Materials and Methods: The study dealt with two parts: The first part included collecting clinical samples from the University Children’s Hospital in Damascus/bacterial diagnostic laboratories/then isolating and diagnosing the bacteria by following a set of tests to identify the most prevalent genera and species and comparing their prevalence rate with Enterococcus. The second part;It included collecting plant samples, confirming the species taxonomically, then extracting alkaloids from plant parts (fruit, stem, Flowers), then comparing the extent of resistance of bacterial strains to antibiotics compared to the Enterococcus sp., and then confirming the antibacterial activity of the Papaver sp. alkaloids against Enterococcus sp. Result:In its first part, the study confirmed the significant contribution of the Enterococcus sp. to infections acquired from various sources, largely in catheter tip infections (9.09%) and to a lesser extent in other sources (3.7%), The second part was to confirm the effective-ness of the alkaloid extract of the Papaver sp., especially the two species Papaver syriacum, and Papaver dubium, against Enterococcus sp. with areole diameters that ranged between (15 - 26 mm) for the fruit extract and at a minimum inhibitory concentration (3.12 - 6.25 mml) and then the stem (5 - 20 mm). And the effectiveness of the Flowers extract is very weak to almost non-existent. Conclusions: The catheter and medical sources surrounding the patient constitute a dangerous source of multi-resistant Enterococcus sp., which poses a real threat to the lives of children, with new mechanisms represented by colonization of the skin and the ability to form biofilms Surfaces of medical instruments, with are resistant to a wide range of antibiotics. As an alternative and effective modern source to limit its spread in the future, the alkaloid extract of the fruits and stems of the wild Papaver sp. has proven a strong antibiotic effect, especially the two types: Papaver syriacum and Papaver dubium.

Pharmacokinetics of Gelsemium elegans in female rats

Background:Gelsemium elegans Benth(G.elegans)is a poisonous perennial evergreen vine plant that has been applied in livestock production and veterinary clinical practice.Early studies found that the toxicity of G.elegans showed significant gender differences in rats,but the underlying reasons for this difference are still not well understood.Methods:In order to explore whether the gender differences in the toxicity of G.elegans are related to pharmacokinetic differences,based on the previous pharmacokinetic study of multiple components of G.elegans in male rats,this study used HPLC-MS/MS method established in the laboratory to conduct a pharmacokinetic study of multiple alkaloids in the plasma of female rats after a single gavage administration of G.elegans(dose of 0.1 g/kg).Results:Through detection,17 alkaloid components in the plasma of female rats were identified,and the pharmacokinetic parameters of 11 of these alkaloids were calculated.We find that in female rats.The T_(max)values were generally less than 0.5 h,and the T_(1/2)values exceeded 3 h,with the longest reaching up to 32.80 h half elimination time.Additionally,the C_(max)and AUC results indicated that female rats had generally higher absorption and exposure levels for most alkaloids.Conclusion:These results suggest that the reason for the differences in the toxicology of G.elegans may be related to the absorption and exposure of gelsemidine-type alkaloids in animals.

Deeply functional identification of TCS1 alleles provides efficient technical paths for low-caffeine breeding of tea plants

Caffeine is an important functional component in tea,which has the effect of excitement and nerve stimulation,but excessive intake can cause insomnia and dysphoria.Therefore,the production of tea with low-caffeine content can meet the consumption needs of certain people.Here,in addition to the previous alleles of the tea caffeine synthase(TCS1)gene,a new allele(TCS1h)from tea germplasms was identified.Results of in vitro activity analysis showed that TCS1h had both theobromine synthase(TS)and caffeine synthase(CS)activities.Site-directed mutagenesis experiments of TCS1a,TCS1c,and TCS1h demonstrated that apart from the 225th amino acid residue,the 269th amino acid also determined the CS activity.GUS histochemical analysis and dual-luciferase assay indicated the low promoter activity of TCS1e and TCS1f.In parallel,insertion and deletion mutations in large fragments of alleles and experiments of site-directed mutagenesis identified a key cis-acting element(G-box).Furthermore,it was found that the contents of purine alkaloids were related to the expression of corresponding functional genes and alleles,and the absence or presence and level of gene expression determined the content of purine alkaloids in tea plants to a certain extent.In summary,we concluded TCS1 alleles into three types with different functions and proposed a strategy to effectively enhance low-caffeine tea germplasms in breeding practices.This research provided an applicable technical avenue for accelerating the cultivation of specific low-caffeine tea plants.

Alkaloids as potential antivirals.A comprehensive review

Alkaloids are a diverse group of natural phytochemicals.These phytochemicals in plants provide them protection against pests,and herbivorous organisms and also control their development.Numerous of these alkaloids have a variety of biological effects,and some have even been developed into medications with different medicinal properties.This review aims to provide a broad overview of the numerous naturally occurring alkaloids(isolated from both terrestrial and aquatic species)along with synthetically produced alkaloid compounds having prominent antiviral properties.Previous reviews on this subject have focused on the biological actions of both natural and synthetic alkaloids,but they have not gone into comprehensive detail about their antiviral properties.We reviewed here several antiviral alkaloids that have been described in the literature in different investigational environments i.e.(in-vivo,in-ovo,in-vitro,and in-silico),and found that these alkaloid compounds have significant antiviral properties against several infectious viruses.These alkaloids repressed and targeted various important stages of viral infection at non-toxic doses while some of the alkaloids reported here also exhibited comparable inhibitory activities to commercially used drugs.Overall,these anti-viral effects of alkaloids point to a high degree of specificity,implying that they could serve as effective and safe antiviral medicines if further pursued in medicinal and pharmacological investigations.

A Pair of New Spirocyclic Alkaloid Enantiomers with TrxR Inhibitory Activities Were Isolated from Marine-Derived Aspergillus ruber TX-M4-1

One new spirocyclic alkaloid,5-isopentenyl-cryptoechinuline D(1),along with 11 known compounds(2–12),were iso-lated from a marine fungus Aspergillus ruber TX-M4-1.The structures of compounds 1–12 were elucidated by spectroscopic evi-dences.Compound 1 was initially isolated as an enantiomer,and further separation of 1 by chiral HPLC afforded a pair of enantio-mers,including(-)-5-isopentenyl-cryptoechinuline D(1a)and(+)-5-isopentenyl-cryptoechinuline D(1b).Their absolute configura-tions were elucidated by ECD spectroscopic data.Compounds 1a,5 and 10 could inhibit thioredoxin reductase(TrxR)activity with IC50 values of 6.2,36.3 and 18.6μmol L^(-1),respectively.Surface plasmon resonance(SPR)study also demonsrated the interactions between compounds 6,8 and Niemann-Pick C1 Like 1(NPC1L1)respectively,which indicate that compounds 6 and 8 are potential NPC1L1 inhibitors.

New Neuraminidase Inhibitory Alkaloids from the Mangrove Soil-Derived Fungus Arthrinium sp.SCSIO 41305

New alkaloid,(E)-2-(hydroxyimino)-4-methylpentanamide(1)and a new cyclopentano[b]pyridine,4-hydroxy-7-methyl-6,7-dihydro-5H-cyclopenta[c]pyridin-5-one(2),together with ten known compounds(3–12)were isolated from the mangrove soil-derived fungus Arthrinium sp.SCSIO 41305.Extensive spectroscopic analysis and X-Ray crystallographic analysis were used to elucidate the structure of(E)-2-(hydroxyimino)-4-methylpentanamide(1),including its absolute configuration.All the isolated compounds(1–12)were evaluated for their antimicrobial and enzyme inhibitory activities against acetylcholinesterase(ACh E),neuraminidase(NAs),and phosphatidylinositol 3-kinase(PI3K).Among them,compounds 1 and 3 exhibited strong neuraminidase inhibitory activity with IC_(50)values of 12.04,1.92μmol L^(-1)(IC_(50)20μmol L^(-1)for oseltamivir acid),while compounds 5,6,8,and 10showed moderate neuraminidase inhibitory activity,and compounds 6–10 displayed weak enzyme inhibitory activities against PI3K.

Design,Synthesis and Bioactivity Study of Marine Alkaloid Neobacillamide-A Derivatives

The Janus kinases(JAKs)are a family of intracellular tyrosine kinases that play an essential role in many basic biological processes,such as apoptosis and inflammation.Thus any dysfunction of the proteins in this pathway may lead to a variety of diseases,including cancer and diseases that affect the immune system,such as severe combined immune deficient(SCID).Marine biological resources have become an important source in new drug research and development due to their diversity,complexity and speciality.In this study,Marine alkaloid Neobacillamide A was isolated from the greedy and stubborn sponge symbiotic Bacillus atrophicus C89 in the South China Sea.Totally 24 novel marine alkaloid Neobacillamide A derivatives were designed and synthesized,which were evaluated for their inhibitory activity against JAK/STAT signaling pathway and their cytotoxicity to A549 cells.Compounds 13c,13o,14d,14g and 14h showed potent JAK/STAT inhibition capability(concentration of 25μmol L^(-1),all inhibitory potencies were above 60%),especially compound 14g exhibited superior JAK/STAT inhibition effect(89.70%inhibition).In addition,all these compounds with a concentration of 25μmol L^(-1)displayed weak or no cytotoxicity to A549 cells,which means that these Neobacillamide A derivatives with JAK/STAT inhibition capability may have potential anti-inflammatory function.

Metabolic and transcriptomic analyses elucidate a novel insight into the network for biosynthesis of carbohydrate and secondary metabolites in the stems of a medicinal orchid Dendrobium nobile

Dendrobium nobile is an important medicinal and nutraceutical herb.Although the ingredients of D.nobile have been identified as polysaccharides,alkaloids,amino acids,flavonoids and bibenzyls,our understanding of the metabolic pathways that regulate the synthesis of these compounds is limited.Here,we used transcriptomic and metabolic analyses to elucidate the genes and metabolites involved in the biosynthesis of carbohydrate and several secondary metabolites in the stems of D.nobile.A total of 1005 metabolites and 31,745 genes were detected in the stems of D.nobile.The majority of these metabolites and genes were involved in the metabolism of carbohydrates(fructose,mannose,glucose,xylulose and starch),while some were involved in the metabolism of secondary metabolites(alkaloids,β-tyrosine,ferulic acid,4-hydroxybenzoate and chrysin).Our predicted regulatory network indicated that five genes(AROG,PYK,DXS,ACEE and HMGCR) might play vital roles in the transition from carbohydrate to alkaloid synthesis.Correlation analysis identified that six genes(ALDO,PMM,BGLX,EGLC,XYLB and GLGA) were involved in carbohydrate metabolism,and two genes(ADT and CYP73A) were involved in secondary metabolite biosynthesis.Our analyses also indicated that phosphoenol-pyruvate(PEP) was a crucial bridge that connected carbohydrate to alkaloid biosynthesis.The regulatory network between carbohydrate and secondary metabolite biosynthesis established will provide important insights into the regulation of metabolites and biological systems in Dendrobium species.

Discovery of prenylated indole alkaloid and natural xanthone from cold-seep sediment derived fungus Talaromyces funiculosus SD-523

A new prenylated indole alkaloid 11,17-epi-mangrovamide A(1),a new natural occurring product,1,7-dihydroxy-6-methyl-8-hydroxymethyl-xanthone(2),two known alkaloids,mangrovamide A(3)and mangrovamide G(4),and four known polyketide derivatives(5–8)were isolated and identified from the cold-seep sediment derived fungal strain Talaromyces funiculosus SD-523.Their structures were elucidated by combination of nuclear magnetic resonance(NMR),high resolution electrospray ionization mass spectroscopy(HRESIMS),quantum chemical electronic circular dichroism(ECD),and DP4+probability analysis as well as by comparison of the data with literature reports.All isolated compounds were tested for antibacterial activities.

Anti-inflammatory maistemonine-class alkaloids of Stemona japonica

Three hitherto undescribed Stemona alkaloids,named stemajapines A-C(1-3),along with six known alkaloids(4-9),were isolated and identified from the roots of Stemona japonica(Blume)Miq.(Stemonaceae).Their structures were established by the analysis of the mass data,NMR spectra,and computational chemistry.Stemjapines A and B were degraded maistemonines without spiro-lactone ring and skeletal methyl from maistemonine.Concurrence of alkaloids 1 and 2 revealed an undescribed way to form diverse Stemona alkaloids.Bioassay results disclosed the anti-inflammatory natural constituents stemjapines A and C with IC_(50) values of 19.7 and 13.8μM,respectively,compared to positive control dexamethasone with 11.7μM.The findings may point out a new direction of Stemona alkaloids inaddition to its traditional antitussive and insecticide activities.

Uncarialines A-E,new alkaloids from Uncaria rhynchophylla and their anticoagulant activity

Uncarialines A-E(1-5),five undescribed monoterpene indole alkaloids,together with five known analogues were obtained from the stems of Uncaria rhynchophylla.Alkaloids 1-3 were unique 3,4-seco-tricyclic alkaloids with a 6/5/10 ring system,while 4 and 5 possessed a rare rearranged scaffold originated from corynantheine-type alkaloids with C-2/C-7 oxidation.Their structures were characterized by a comprehensive analysis of MS,NMR,and ECD.Their effects on blood clotting times of human plasma were evaluated and alkaloid 5 had a slight prolongation effect on both thrombin time and activated partial thromboplastin time(p<0.001).

Biological Activity and Molecular Mechanism of Bullatine G

Bullatine G has many biological effects such as anti-inflammatory,anti-anxiety,anti-tumor,anti-arrhythmia and anti-heart failure effect.In order to provide a theoretical basis for the further study and clinical application of bullatine G,this article reviews the biological activity of bullatine G in recent years.

Effects of Different Alkaloids in Coptis chinensis on Inhibiting TGEV Proliferation

[Objectives]To study the effects of different alkaloids in Coptis chinensis on inhibiting the proliferation of Transmissible gastroenteritis virus(TGEV).[Methods]The components and content of the main alkaloids in the extract of C.chinensis were analyzed.The main alkaloids were selected as drugs to inhibit the proliferation of TGEV.The maximum non-toxic concentration of Columbamine,Jatrorrhizine,Epiberberine,Coptisine,Palmatine,and Berberine was screened.The protective rate of each drug on TGEV-infected ST cells was determined,and the transcriptional inhibitory effect of the drug on TGEV N gene was detected by fluorescent quantitative PCR.[Results]The extract of C.chinensis mainly contains 6 alkaloids:Columbamine,Jatrorrhizine,Epiberberine,Coptisine,Palmatine,and Berberine,accounting for 2.03%,8.88%,9.21%,15.07%,14.63%,and 50.18%,respectively.In the range of the safe concentration,Jatrorrhizine,Palmatine,and Coptisine had better protective effects on ST cells infected with TGEV;compared with the Columbamine group,the cell protection rate was significantly different(P<0.05);compared with the Berberine group,the difference was extremely significant(P<0.01).The Coptisine and Palmatine groups had significant inhibitory effects on the transcription of TGEV N gene,and the difference was extremely significant compared with the virus group(P<0.05).[Conclusions]Jatrorrhizine and Palmatine in C.chinensis are the main components to inhibit the proliferation of TGEV.

Phytochemical Screening of Some Medicinal Plants in Al Jouf, KSA

The utilization of ethnobotanical and phytochemical investigations in the discovery of novel medications is beneficial. Screening for phytochemicals is an important step in detecting the bioactive ingredients of medicinal plants which are used in conventional therapy. For the first time, 23 medicinal plants utilized in Saudi Arabian traditional therapy were examined. From August 2020 to July 2021, ethnobotanical fieldwork was conducted. There was some plant species identified, divided into pertinent families. Standard procedures were used to screen these medicinal plants for the occurrence of glycosides, alkaloids, saponins, resins, saponins, tannins, and flavonoids. Among the medicinal plants used, the most common phytochemicals were alkaloids (95.65%), glycosides (86.96%), saponin (82.61%), tannins (73.91%), flavonoids (56.52%), and resin (52.17%). The least widely distributed chemicals, on the other side, were resins. Trigonella foenum-graecum L., Pimpinella anisum L., and Cuminum cyminum L. seeds were shown to contain all six categories of secondary metabolites. The ethnographic importance of these medicinal plants is consistent with the content of secondary metabolites.

Differential accumulation mechanisms of purine alkaloids and catechins in Camellia ptilophylla,a natural theobromine-rich tea

Tea is consumed worldwide due to its charming flavor and the refreshing effects conferred by caffeine.Caffeine however has undesirable side effects,such as sleep disturbance.Camellia ptilophylla is known for its low caffeine content,and the biosynthesis of purine alkaloids in this species has become a hot topic.In this study,the accumulation of purine alkaloids in a natural C.ptilophylla population(32 plants)was analyzed,and the results showed that 81.25%of this population were caffeine-free,containing only theobromine(TB),while six plants contained both theobromine and caffeine(CAF).RNA-seq analysis of two C.ptilophylla plants with contrasting purine alkaloid contents(TB and CAF)revealed that xanthosine synthesis genes of the SAM cycle and AMP pathway were significantly related to the differential accumulation of purine alkaloids between TB and CAF.The high theobromine content in TB was attributed to the significantly higher expression of TCS-2,TCS-3 and MXMTs and downregulation of the xanthosine degradation pathway in comparison to CAF.Additionally,CsMYB184 was significantly upregulated in TB,opposing the expression pattern of TCS1,but consistent with that of other TCSs and MXMTs.Furthermore,the upregulated expression of catechin biosynthesis genes,F3'H,F3'5'H and SCPLs in TB corresponded to a higher gallocatechin gallate(GCG)content.Overall,these findings provide new insights into the accumulation of theobromine and GCG,which may facilitate the development of tea plant cultivars with low-caffeine or high GCG to meet the diverse demands of consumers.

Synergistic effect of pinellia total alkaloids and uncaria total alkaloids on anticonvulsant action in mice and rats

Aim To investigate the synergistic effect of the combination of pinellia total alkaloid （PTA） and uncaria total alkaloid （UTA）, and explore the mechanism of anticonvulsant action. Methods Anticonvulsant and toxic effect profiles of combinations of PTA with UTA, alone and at three fixed ratios of 1：4, 1 ：1, 4：1, were evaluated in maximal electroshock （MES）-induced seizures and acute toxicity test in mice. Respective ED50 and LD50 were calculated with Bliss＇s method. Their synergistic effect were evaluated by isobolographic analysis and allowed the determination of benefit indices （BI） for respective combinations. The model of convulsive rats kindled by penicillin topically injected into cortex was used to investigated the content of Glu, Asp, Gly and GABA in hippocampus using high performance liquid chromatography （HPLC）. Results Combinations of PTA and UTA at the ratio of 4：1 were synergistic in MES test and antagonistic in acute toxicity test, showing the best profile for combinations of PTA with UTA. In contrast, the ratios of 1 ：4 and 1 ： 1, despite synergistic in MES test, were additive in acute toxicity test. The 4：1 combination and two drugs alone significantly decreased Glu level and increased GABA level in the hippocampus, but the GABA level in the 4：1 combination group was higher than that in the two drugs alone groups. They did not have significant influence on the levels of ASp and Gly. Conclusion Combinations of PTA and UTA at 4：1 ratio demonstrated synergistic effect in anticonvulsant action and antagonistic effect in toxicity. The anticonvulsant mechanism might be related to decreasing the excitability of Glutamatergic neurons and increasing the inhibition of GABAergic neurons.

Two Novel Hydroperoxylated Lycopodium Alkaloids from Huperzia serrata

Two novel hydroperoxylated Lycopodium alkaloids, 11alpha-hydroperoxyphlegmariurine B (1) and 7-hydroperoxyphlegmariurine B (2), along with a known compound, phlegmanurine B (3), were isolated from the total alkaloid fraction of the Chinese medicinal herb Huperzia serrata (Thunb.) Trev. Their structures and relative configurations were elucidated on the basis of spectroscopic analyses.