Synthesis and antifungal evaluation of chalcone derivatives combined with fluconazole against drug-resistant Candida albicans / 中国药科大学学报

@#Chalcone is a common scaffold in natural products with optimal properties and biological activities.In this study, we designed and prepared eight new coumarin-chalcone derivatives (5a-5h), and confirmed their structures by 1H NMR and 13C NMR. Their in vitro antifungal activity combined with fluconazole (FLC) against drug-resistant Candida albicans was tested by microdilution method.The results indicated that most chalcone derivatives showed good antifungal activity against drug resistant Candida albicans with FLC, particularly with compound 5g displaying better antifungal activity (MIC50 = 5.60 μg/mL) than FLC (MIC50 = 200 μg/mL) when combined with FLC, so, these derivatives could be used as synergists of antifungal drugs.

Cloning and catalytic analysis of Isatis indigotica chalcone isomerase in vitro / 中国中药杂志

Chalcone isomerase is a key rate-limiting enzyme in the biosynthesis of flavonoids in higher plants, which determines the production of flavonoids in plants. In this study, RNA was extracted from different parts of Isatis indigotica and reverse-transcribed into cDNA. Specific primers with enzyme restriction sites were designed, and a chalcone isomerase gene was cloned from I. indigotica, named IiCHI. IiCHI was 756 bp in length, containing a complete open reading frame and encoding 251 amino acids. Homology analysis showed that IiCHI was closely related to CHI protein of Arabidopsis thaliana and had typical active sites of chalcone isomerase. Phylogenetic tree analysis showed that IiCHI was classified into type Ⅰ CHI clade. Recombinant prokaryotic expression vector pET28a-IiCHI was constructed and purified to obtain IiCHI recombinant protein. In vitro enzymatic analysis showed that the IiCHI protein could convert naringenin chalcone into naringenin, but could not catalyze the production of liquiritigenin by isoliquiritigenin. The results of real-time quantitative polymerase chain reaction(qPCR) showed that the expression level of IiCHI in the aboveground parts was higher than that in the underground parts and the expression level was the highest in the flowers of the aboveground parts, followed by leaves and stems, and no expression was observed in the roots and rhizomes of the underground parts. This study has confirmed the function of chalcone isomerase in I. indigotica and provided references for the biosynthesis of flavonoid components.

Geranylated or prenylated flavonoids from Cajanus volubilis / 中国天然药物

Five new flavonoid derivatives, cajavolubones A-E (1-5), along with six known analogues (6-11) were isolated from Cajanus volubilis, and their structures were elucidated by spectroscopic analysis and quantum chemical calculations. Cajavolubones A and B (1 and 2) were identified as two geranylated chalcones. Cajavolubone C (3) was a prenylated flavone, while cajavolubones D and E (4 and 5) were two prenylated isoflavanones. Compounds 3, 8, 9 and 11 displayed cytotoxicity against HCT-116 cancer cell line.

Cloning, expression and activity analysises of chalcone synthase genes in Carthamus tinctorius / 中草药·英文版

OBJECTIVE@#Flavonoids are the bioactive compounds in safflower (Carthamus tinctorius), in which chalcone synthase (CHS) is the first limiting enzyme. However, it is unclear that which chalcone synthase genes (CHSs) are participated in flavonoids biosynthesis in C. tinctorius. In this study, the CHSs in the molecular characterization and enzyme activities were investigated.@*METHODS@#Putative chalcone biosynthase genes were screened by the full-length transcriptome sequences data in C. tinctorius. Chalcone biosynthase genes in C. tinctorius (CtCHSs) were cloned from cDNA of flowers of C. tinctorius. The cloned gene sequences were analyzed by bioinformatics, and their expression patterns were analyzed by real-time PCR (RT-PCR). The protein of CtCHS in the development of flowers was detected by polyclonal antibody Western blot. A recombinant vector of CtCHS was constructed. The CtCHS recombinant protein was induced and purified to detect the enzyme reaction (catalyzing the reaction of p-coumaryl-CoA and malonyl-CoA to produce naringin chalcone). The reaction product was detected by HPLC and LC-MS.@*RESULTS@#Two full-length CtCHS genes were successfully cloned from the flowers of safflower (CtCHS1 and CtCHS3), with gene lengths of 1525 bp and 1358 bp, respectively. RT-PCR analysis showed that both genes were highly expressed in the flowers, but the expression of CtCHS1 was higher than that of CtCHS3 at each developmental stage of the flowers. WB analysis showed that only CtCHS1 protein could be detected at each developmental stage of the flowers. HPLC and LC-MS analyses showed that CtCHS1 could catalyze the conversion of p-coumaryl-CoA and malonyl-CoA substrates to naringin chalcone.@*CONCLUSION@#CtCHS1 is involved in the biosynthesis of naringin chalcone in safflower.

Site-directed mutagenesis enhances the activity of benzylidene acetone synthase of polyketide synthase from Polygonum cuspidatum / 生物工程学报

Polygonum cuspidatum polyketide synthase 1 (PcPKS1) has the catalytic activity of chalcone synthase (CHS) and benzylidene acetone synthase (BAS), which can catalyze the production of polyketides naringenin chalcone and benzylidene acetone, and then catalyze the synthesis of flavonoids or benzylidene acetone. In this study, three amino acid sites (Thr133, Ser134, Ser33) that may affect the function of PcPKS1 were identified by analyzing the sequences of PcPKS1, the BAS from Rheum palmatum and the CHS from Arabidopsis thaliana, as well as the conformation of the catalytic site of the enzyme. Molecular modification of PcPKS1 was carried out by site-directed mutagenesis, and two mutants were successfully obtained. The in vitro enzymatic reactions were carried out, and the differences in activity were detected by high performance liquid chromatography (HPLC). Finally, mutants T133LS134A and S339V with bifunctional activity were obtained. In addition to bifunctional activities of BAS and CHS, the modified PcPKS1 had much higher BAS activity than that of the wild type PcPKS1 under the conditions of pH 7.0 and pH 9.0, respectively. It provides a theoretical basis for future use of PcPKS1 in genetic engineering to regulate the biosynthesis of flavonoids and raspberry ketones.

Design, synthesis and anti-cervical cancer activity of novel trifluoromethyl chalcones derivatives / 中国药科大学学报

@#Chalcones are polyphenolic flavonoid substances with various pharmacological effects and low toxicity.In this study, 15 novel trifluoromethyl chalcone derivatives (3a-3o) were designed and synthesized using the chalcone nucleus of natural licorice chalcone as the lead compound skeleton in order to find the candidate drugs with high efficiency and low toxicity against cervical cancer.The structures of the target compounds were confirmed by 1H NMR, 13C NMR and HRMS. The inhibitory activities of compounds 3a-3o, licorice chalcone, cisplatin and Nutlin3a on SiHa, HeLa and C-33A human cervical cancer cells and H8 and HaCaT normal cells were determined by MTT assay, and the structure-activity relationship was analyzed.Transwell and flow cytometry methods were used to assess the target compounds'' ability to inhibit cell migration and invasion, promote apoptosis, and arrest the cell cycle.Molecular docking technology was used to further study the binding characteristics of the target compound with MDM2 protein.The results showed that the compounds had different degrees of inhibitory activity against the three types of cervical cancer cells.Compound 3n showed the strongest activity against HeLa cells (IC50 = 11.69 μmol/L), which was superior to the lead compound, and had lower toxicity against the two normal cells.Compound 3n was found to significantly inhibit the migration and invasion of HeLa cells, induce apoptosis and arrest the cell cycle at G2/M phase.The results of molecular docking showed that the effective binding of compound 3n to MDM2 protein may be one of its anti-tumor mechanisms.This study provides an experimental basis for the screening of new anti-cervical cancer candidate drug from chalcone derivatives.

Anti-pseudo-allergic components in licorice extract inhibit mast cell degranulation and calcium influx / 中国天然药物

Pseudo-allergic reactions (PARs) widely occur upon application of drugs or functional foods. Anti-pseudo-allergic ingredients from natural products have attracted much attention. This study aimed to investigate anti-pseudo-allergic compounds in licorice. The anti-pseudo-allergic effect of licorice extract was evaluated in rat basophilic leukemia 2H3 (RBL-2H3) cells. Anti-pseudo-allergic compounds were screened by using RBL-2H3 cell extraction and the effects of target components were verified further in RBL-2H3 cells, mouse peritoneal mast cells (MPMCs) and mice. Molecular docking and human MRGPRX2-expressing HEK293T cells (MRGPRX2-HEK293T cells) extraction were performed to determine the potential ligands of MAS-related G protein-coupled receptor-X2 (MRGPRX2), a pivotal target for PARs. Glycyrrhizic acid (GA) and licorice chalcone A (LA) were screened and shown to inhibit Compound48/80-induced degranulation and calcium influx in RBL-2H3 cells. GA and LA also inhibited degranulation in MPMCs and increase of histamine and TNF-α in mice. LA could bind to MRGPRX2, as determined by molecular docking and MRGPRX2-HEK293T cell extraction. Our study provides a strong rationale for using GA and LA as novel treatment options for PARs. LA is a potential ligand of MRGPRX2.

Cloning and function analysis of chalcone isomerase gene and chalcone synthase gene in Lonicera macranthoides / 中国中药杂志

In order to explore the functions of genes of key rate-limiting enzymes chalcone isomerase(CHI) and chalcone synthase(CHS) in the biosynthesis of flavonoids in Lonicera macranthoides, this study screened and cloned the cDNA sequences of CHI and CHS genes from the transcriptome data of conventional variety and 'Xianglei' of L. macranthoides. Online bioinformatics analysis software was used to analyze the characteristics of the encoded proteins, and quantitative reverse-transcription polymerase chain reaction(qRT-PCR) to detect the expression of CHI and CHS in different parts of the varieties at different flowering stages. The content of luteo-loside was determined by high performance liquid chromatography(HPLC) and the correlation with the expression of the two genes was analyzed. The results showed that the CHI and CHS of the two varieties contained a 627 bp and 1170 bp open reading frame(ORF), respectively, and the CHI protein and CHS protein were stable, hydrophilic, and non-secretory. qRT-PCR results demonstrated that CHI and CHS of the two varieties were differentially expressed in stems and leaves at different flowering stages, particularly the key stages. Based on HPLC data, luteoloside content was in negative correlation with the relative expression of the genes. Thus, CHI and CHS might regulate the accumulation of flavonoids in L. macranthoides, and the specific functions should be further studied. This study cloned CHI and CHS in L. macranthoides and analyzed their expression for the first time, which laid a basis for investigating the molecular mechanism of the differences in flavonoids such as luteoloside in L. macranthoides and variety breeding.

Cytotoxicity study on FC58, an indole-chalcone, against multi-drug resistant leukemia cells / 药学实践杂志

Objective To synthesize and investigate cytotoxicity of an indole-chalcone derivative FC58. Methods The target compound was synthesized through the Aldol condensation with 1-(3,4,5-trimethoxyphenyl)ethan-1-one and 1H-indole-3-carbaldehyde. The Cell Titer-Blue method was used to determine in vitro cytotoxicity. The cell cycle experiment was performed to analyze the action characteristics of FC58. Results FC58 exhibited high cytotoxicity against various leukemia cells and resulted in G2/M phase arrest. It showed stronger drug resistant index than traditional tubulin inhibitors such as paclitaxel, vinblastine and doxorubicin. Conclusion FC58 represents a promising lead compound for multi-drug resistant leukemia.

Overexpressing of chalcone isomerase (CHI) gene enhances flavonoid accumulation in Glycyrrhiza uralensis hairy roots / 药学学报

Chalcone isomerase (CHI) is the second rate-limiting enzyme involved in the biosynthetic pathway of flavonoids in Glycyrrhiza uralensis. Based on our previous studies, we selected the specific CHI haplotype (GenBank Accession No. KY115232) to maximize flavonoid accumulation. We constructed a plant binary expression vector for overexpression of this CHI gene by the gene fusion method and transfected the plasmid into Agrobacterium tumefaciens ACCC10060 by electroporation. The recombinant A. tumefaciens ACCC10060 subsequently was used to infect cotyledons and hypocotyls of G. uralensis to obtain transgenic hairy roots. A qRT-PCR method was used to determine the copy number of CHI and a UPLC method was used to assay the content of four flavonoids in different hairy root lines. The qRT-PCR results showed that the copy number of CHI in hairy roots was 1 or 5. UPLC results showed that the content of total flavonoids, liquiritin, liquiritigenin, and isoliquiritigenin in transgenic hairy root samples was significantly higher than that in wild-type samples. This study demonstrates that overexpression of CHI significantly increases the content of flavonoids in hairy roots of G. uralensis. This work provides a theoretical basis for clarifying the function of CHI. Three transgenic hairy root lines of G. uralensis were isolated which can be used to increase the accumulation of licorice flavonoids in vitro.

Cloning and expression analysis of chalcone isomerase from Aquilaria sinensis / 药学学报

Chalcone isomerases (CHIs) play an essential role in the biosynthesis of flavonoids important in plant self-defense. Based on the transcriptome data of Aquilaria sinensis Calli, a full-length cDNA sequence of CHI1 (termed as AsCHI1) was cloned by reverse transcription PCR. AsCHI1 contains a complete open frame (ORF) of 654 bp. The deduced protein is composed of 217 amino acids, with a predicted molecular weight of 23.11 kDa. The sequence alignment and phylogenetic analysis revealed that AsCHI1 has conserved most of the active site residues in type I CHIs, indicating a close relationship with the CHI from Gossypium hirsutum. The recombinant AsCHI1 protein was obtained by heterologous expression of AsCHI1 in E. coli BL21(DE3). The purified AsCHI1 protein exhibited CHI activity by catalyzing the production of naringenin from naringenin chalcone. Remarkably, AsCHI1 expression in A. sinensis Calli treated with various abiotic stresses including salt, mannitol, cold, and heavy metals could be markedly increased, and plant hormones such as abscisic acid (ABA), gibberellin (GA3), and salicylic acid (SA) could also increase the expression of AsCHI1, suggesting that AsCHI1 might play an important role in plant self-defense. The results expand our understanding of the biosynthesis of flavonoids in A. sinensis and give further insight into the defensive responses of A. sinensis to abiotic and biotic stresses.

Design, synthesis, characterization, and cytotoxicity activity evaluation of mono-chalcones and new pyrazolines derivatives

The development of resistance and side effects of chemotherapeutic drugs are common obstacles in the treatmentof cancer. With the expansion of health problems nowadays, there is a need to continuously develop new drugs thatare more efficient in targeting tumor cells and safe to normal cells. This study designed a series of new chalconesand pyrazoline derivatives based on their binding energy from the molecular docking study. The synthesis involvedClaisen–Schmidt condensation to form two chalcones, 1 and 2, which are then cyclized at room temperature to formeight new pyrazoline derivatives, 3–10. A one-pot reaction of acetophenone, 2-ethoxybenzaldehyde, and hydrazidederivatives (thiosemicarbazide and phenyl hydrazide) under reflux formed two new pyrazoline derivatives, 11 and12, without the isolation of chalcones. All the synthesized chalcones and pyrazolines were characterized using theFourier transform infrared spectroscopy–attenuated total reflectance and nuclear magnetic resonance (1D and 2D).The cytotoxicity activity of the chalcones and new pyrazoline compounds were investigated against breast cancercell lines (MCF-7 and MD-MB-231) and normal breast cell lines (MCF-10A). The results show that only compound7 showed the minimum inhibition against MCF-7 with IC50 6.50µM when exposed to the cell line for 24 hourscompared to the reference Gefitinib anticancer drug

Novel aminoalkylated chalcone: Synthesis, biological evaluation, and docking simulation as potent antimalarial agents

Three chalcone derivatives with amine groups (4a–c) were synthesized and evaluated for their antimalarial activity.Three aminoalkylated chalcone derivatives (4a–c) have been prepared through Claisen–Schmidt condensation reactionfrom vanillin and chloroacetophenone, followed by the Mannich reaction to add amine group. The structure of thecompounds was confirmed by the spectrophotometric analysis using mass spectrometers (MS) and proton and carbonnuclear magnetic resonance (1H- and 13C-NMR) spectroscopy. Antimalarial activity of 4a–c was evaluated againstPlasmodium falciparum (3D7) strain, and the molecular docking of 4b was performed to understand the interactionagainst Pf DHFR-TS protein (1J3I.pdb). The prepared aminoalkylated chalcone (4a–c) was obtained in a yield of 80%,75%, and 70%. The addition of morpholine (4a), piperidine (4b), and diethylamine (4c) as amine groups significantlycould improve the antimalarial activity with IC50 of 0.62, 0.54, and 1.12 µM, respectively (strong activity), comparedwith the chalcone without amine group (3) with IC50 of 25.84 µM (moderate activity). The molecular docking ofcompound 4b exhibited strong hydrogen bond interaction with ILE112, ILE64, SER111, SER108, ASP54, TYR170,and PRO113 residues with CDOCKER interaction energy of −48.84 kcal/mol. Thus, aminoalkylated chalcone couldbe proposed for further studies and developed into antimalarial drug candidates

Synthesis, anticancer activity, and docking study of N-acetyl pyrazolines from veratraldehyde

N-acetyl pyrazoline derivatives A–C containing methoxy and chloro/hydroxyl substituents were synthesized andtested for their cytotoxic activities. The precursor chalcones A–C which were obtained from the condensation reactionbetween veratraldehyde and acetophenone derivatives were reacted with hydrazine hydrate in the presence of glacialacetic acid to give pyrazolines A–C with excellent yield and purity. Characterization of all products was done usingFourier transform infrared (FTIR), nuclear magnetic resonance (NMR) and gas chromatography-mass spectrometers.(GC-MS). Cytotoxicity evaluation of pyrazolines revealed that pyrazoline A has moderate activity against breastcancer cell line MCF7 (IC50 40.47 µg/ml), breast cancer cell line T47D (IC50 26.51 µg/ml), and cervical cancer cell lineHeLa (IC50 31.19 µg/ml). Pyrazoline B is inactive against all tested cancer lines (IC50 > 100 µg/ml). Pyrazoline C hasmoderate activity against MCF7 (IC50 94.02 µg/ml), but inactive against T47D and HeLa. Docking study showed theinteraction between pyrazolines and EGFR receptor via hydrogen bonds and π-cation interactions.

Synthesis, anticancer activity, and docking study of N-acetyl pyrazolines from veratraldehyde

N-acetyl pyrazoline derivatives A–C containing methoxy and chloro/hydroxyl substituents were synthesized andtested for their cytotoxic activities. The precursor chalcones A–C which were obtained from the condensation reactionbetween veratraldehyde and acetophenone derivatives were reacted with hydrazine hydrate in the presence of glacialacetic acid to give pyrazolines A–C with excellent yield and purity. Characterization of all products was done usingFourier transform infrared (FTIR), nuclear magnetic resonance (NMR) and gas chromatography-mass spectrometers.(GC-MS). Cytotoxicity evaluation of pyrazolines revealed that pyrazoline A has moderate activity against breastcancer cell line MCF7 (IC50 40.47 µg/ml), breast cancer cell line T47D (IC50 26.51 µg/ml), and cervical cancer cell lineHeLa (IC50 31.19 µg/ml). Pyrazoline B is inactive against all tested cancer lines (IC50 > 100 µg/ml). Pyrazoline C hasmoderate activity against MCF7 (IC50 94.02 µg/ml), but inactive against T47D and HeLa. Docking study showed theinteraction between pyrazolines and EGFR receptor via hydrogen bonds and π-cation interactions

In silico predictive for modification of chalcone with pyrazole derivatives as a novel therapeutic compound for targeted breast cancer treatment

One of the most common triggers of breast cancer is over-expression of estrogen receptor alpha (ERα). Long-termtherapy of tamoxifen, an ERα antagonist, can reduce patient’s quality of life because of its side effects. In the previousstudy, 2’,4’-dihydroxy-6-methoxy-3,5-dimethylchalcone (ChalcEA) was isolated as an active compound from theEugenia aquea leaves that is responsible for breast cancer treatment with positive ERα, however, the potency is lowerthan tamoxifen. The aim of this study is to find the best-modified chalcone that binds well with the ERα. Drug designapproaches used in this study were Structure-Based (Autodock 4.1) and Ligand-Based (LiganScout 4.1). Prediction ofabsorption, distribution, and toxicity parameters was employed using preADMET and Toxtree. Interactions betweentamoxifen and ERα were determined and the differences in the binding modes between tamoxifen and chalcones wereobserved. Modifina3 had pharmacophore fit score value of 76.42% and the molecular docking studies showed thelowest free energy binding (∆G) of −11.07 kcal/mol while tamoxifen of −10.15 kcal/mol. Modifina3 had absorptionand distribution properties with the percentage human intestinal absorption of 95.90%, CaCO2 of 46.95%, and proteinplasma binding of 93.55%. Toxicity prediction of Modifina3 was categorized in class III and risk assessment requirescompound specific toxicity data. These results suggest that Modifina3 has the potency to be a novel therapeuticcompound for potent ERα inhibitor targeted breast cancer.

Cloning and prokaryotic expression of CHI in Chrysanthemum morifolium cv.'Hangju' / 中国中药杂志

Three Chrysanthemum-chalcone-isomerase genes( CmCHI) were successfully cloned by PCR from the database of Chrysanthemum transcriptome and named CmCHI1,CmCHI2 and CmCHI3,respectively. Bioinformatics analysis showed that the base numbers of CmCHI1-3 open reading frame were 708,633 and 681 bp,encoding 235,210 and 226 amino acids,respectively. Three fusion proteins of about 30 kDa were successfully induced by prokaryotic expression technology,and the corresponding recombinant fusion proteins were isolated and purified by Ni-NTA resin column. Clustering analysis showed that the 3 CmCHI were homologous with Compositae plants,and CmCHI1 and CmCHI3 belonged to type Ⅰ CHI. CmCHI2 belongs to type Ⅳ CHI. Using β-actin as an internal reference gene,RT-qPCR was used to detect and analyze the expression of CmCHI1-3 genes in Hangju. The results showed that the expression levels of CmCHI1 and CmCHI3 were higher,while the expression levels of CmCHI2 were lower. It was concluded that CmCHI1 and CmCHI3 were the main chalcone isomerase genes involved in the synthesis of flavonoids in Hangju,and CmCHI2 was a helper gene. Flooding treatment significantly promoted the expression of CmCHI1 and CmCHI3 genes,but had no regulatory effect on CmCHI2. The above results provided a basis for further study of the molecular regulation mechanism of CHI gene in the metabolism of flavonoids in Hangju,which laid a foundation for improving the content of flavonoids in Hangju and finally improving the medicinal quality of Hangju.

Cloning and characterization of chalcone synthase and chalcone isomerase genes in Arisaema heterophyllum / 中国中药杂志

Chalcone synthase( CHS) and chalcone isomerase( CHI) are key enzymes in the biosynthesis pathway of flavonoids. In this study,unigenes for CHS and CHI were screened from the transcriptome database of Arisaema heterophyllum. The open reading frame( ORFs) of chalcone synthase( Ah CHS) and chalcone isomerase( Ah CHI) were cloned from the plant by RT-PCR. The physicochemical properties,expression and structure characteristics of the encoded proteins Ah CHS and Ah CHI were analyzed. The ORFs of Ah CHS and Ah CHI were 1 176,630 bp in length and encoded 392,209 amino acids,respectively. Ah CHS functioned as a symmetric homodimer. The N-terminal helix of one monomer entwined with the corresponding helix of another monomer. Each CHS monomer consisted of two structural domains. In particular,four conserved residues define the active site. The tertiary structure of Ah CHI revealed a novel open-faced β-sandwich fold. A large β-sheet( β4-β11) and a layer of α-helices( α1-α7) comprised the core structure. The residues spanning β4,β5,α4,and α6 in the three-dimensional structure were conserved among CHIs from different species. Notably,these structural elements formed the active site on the protein surface,and the topology of the active-site cleft defined the stereochemistry of the cyclization reaction. The homology comparison showed that Ah CHS had the highest similarity to the CHS of Anthurium andraeanum,while Ah CHI had the highest similarity to the CHI of Paeonia delavayi. This study provided the basis for the functional study of Ah CHS and Ah CHI and the further study on plant flavonoid biosynthesis pathway.

Cloning,expression and characterization of chalcone isomerase from medicinal plant Chinese sumac (Rhus chinensis) / 中国中药杂志

Flavonoids are a group of secondary metabolites found in plants. They have many pharmacological functions and play an important role in Chinese sumac( Rhus chinensis),which is a well-known traditional Chinese medicinal plant. Chalcone isomerase( CHI,EC 5. 5. 1. 6) is one of the key enzymes in the flavonoids biosynthesis pathway. In this paper,the full-length c DNA sequence encoding the chalcone isomerase from R. chinensis( designated as Rc CHI) was cloned by RT-PCR and rapid-amplification of c DNA Ends( RACE). The Rc CHI c DNA sequence was 1 058 bp and the open reading frame( ORF) was 738 bp. The ORF predicted to encode a 245-amino acid polypeptide. Rc CHI gene contained an intron and two exons. The sequence alignments revealed Rc CHI shared47. 1%-71. 6% identity with the homologues in other plants. Real-time PCR analysis showed that the total flavonoid levels were positively correlated with tissue-specific expressions of Rc CHI mRNA in different tissues. The recombinant protein was successfully expressed in an Escherichia coli strain with the p GEX-6 P-1 vector. In this paper,the CHI gene was cloned and characterized in the family of Anacardiaceae and will help us to obtain better knowledge of the flavonoids biosynthesis of the flavonoid compounds in R. chinensis.

Antifungal activity of extracts and phenolic compounds from Deguelia duckeana

ABSTRACT Candida spp. is associated with almost 80% of all nosocomial fungal infections and is considered a major cause of blood stream infections. In humans, Cryptococcosis is a disease of the lungs caused by the fungi Cryptococcus gattii and Cryptococcus neoformans. It can be potentially fatal, especially in immune-compromised patients. In a search for antifungal drugs, Deguelia duckeana extracts were assayed against these two fungi and also against Candida albicans, which causes candidiasis. Hexane branches and CH2Cl2 root extracts as well as the substances 4-hydroxylonchocarpine, 3,5,4′-trimethoxy-4-prenylstilbene and 3′,4′-methylenedioxy-7-methoxyflavone were assayed to determine the minimal inhibitory concentration. Phytochemical study of CH2Cl2 root and hexane branch extracts from D. duckeana A.M.G. Azevedo, Fabaceae, resulted in the isolation and characterization of nine phenolic compounds: 4-hydroxyderricine, 4-hydroxylonchocarpine, 3′,4′,7-trimethoxy-flavonol, 5,4′-dihydroxy-isolonchocarpine, 4-hydroxyderricidine, derricidine, 3,5,4′-trimethoxy-stilbene, 3′,4′,7-trimethoxyflavone and yangambin. The only active extract was a CH2Cl2 root showing minimal inhibitory concentration 800 µg/ml against C. gattii, and the investigation of compounds obtained from this extract showed that 4-hydroxylonchocarpine was active against all three fungi (C. neoformans, C. gattii and C. albicans). These results suggest that D. duckeana extracts have potential therapeutic value for the treatment of pathogenic fungi.