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1.
Physiol Plant ; 176(5): e14515, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39252390

RESUMO

Cytochrome P450 enzyme (CYP)-catalyzed functional group transformations are pivotal in the biosynthesis of metabolic intermediates and products, as exemplified by the CYP-catalyzed C7-hydroxylation and the subsequent C7-C8 bond cleavage reaction responsible for the biosynthesis of the well-known antitumor monoterpene indole alkaloid (MIA) camptothecin. To determine the key amino acid residues responsible for the catalytic selectivity of the CYPs involved in MIA biosynthesis, we characterized the enzymes CYP72A728 and CYP72A729 as stereoselective 7-deoxyloganic acid 7-hydroxylases (7DLHs). We then conducted a comparative analysis of the amino acid sequences and the predicted structures of the CYP72A homologs involved in camptothecin biosynthesis, as well as those of the CYP72A homologs implicated in the pharmaceutically significant MIAs biosynthesis in Catharanthus roseus. The crucial amino acid residues for the catalytic selectivity of the CYP72A-catalyzed reactions were identified through fragmental and individual residue replacement, catalytic activity assays, molecular docking, and molecular dynamic simulations analysis. The fragments 1 and 3 of CYP72A565 were crucial for its C7-hydroxylation and C7-C8 bond cleavage activities. Mutating fragments 1 and 2 of CYP72A565 transformed the bifunctional CYP72A565 into a monofunctional 7DLH. Evolutionary analysis of the CYP72A homologs suggested that the bifunctional CYP72A in MIA-producing plants may have evolved into a monofunctional CYP72A. The gene pairs CYP72A728-CYP72A610 and CYP72A729-CYP72A565 may have originated from a whole genome duplication event. This study provides a molecular basis for the CYP72A-catalyzed hydroxylation and C-C bond cleavage activities of CYP72A565, as well as evolutionary insights of CYP72A homologs involved in MIAs biosynthesis.


Assuntos
Sistema Enzimático do Citocromo P-450 , Sistema Enzimático do Citocromo P-450/metabolismo , Sistema Enzimático do Citocromo P-450/genética , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Alcaloides Indólicos/metabolismo , Catharanthus/enzimologia , Catharanthus/genética , Catharanthus/metabolismo , Catálise , Alcaloides de Triptamina e Secologanina/metabolismo , Evolução Molecular , Simulação de Acoplamento Molecular , Sequência de Aminoácidos , Hidroxilação , Simulação de Dinâmica Molecular , Monoterpenos/metabolismo , Filogenia
2.
Appl Microbiol Biotechnol ; 107(23): 7031-7042, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37728626

RESUMO

Escherichia coli, a well-known prokaryotic organism, has been widely employed as a versatile host for heterologous overexpression of proteins/biocatalysts and the production of pharmaceutically important intermediates/small molecules. However, some E. coli endogenous enzymes showing substrate promiscuity may disturb the heterologous metabolic flux, which will result in the reduction of substrates, intermediates, and target products. Here we reported an unexpected E. coli-catalyzed regioselective O-acetylation of various glucosides. The regioselectively O-acetylated products, 6'-O-acetyl-loganin and 6'-O-acetyl-loganic acid, were obtained and characterized from the enzymatic reaction in which the supernatants of E. coli expressing either CaCYP72A565 and CaCPR, the key enzymes involved in camptothecin biosynthesis, or empty vector were used as catalyst and loganin and loganic acid as independent substrate. An alkaloidal glucoside strictosamide was converted into the regioselectively O-acetylated product 6'-O-acetyl-strictosamide, implying substrate promiscuity of the E. coli-catalyzed O-acetylation reaction. Furthermore, 8 glucosides, including 5 iridoid glucosides and 3 flavonoid glucosides, were successfully converted into the regioselectively O-acetylated products by E. coli, indicating the wide substrate range for the unexpected E. coli-catalyzed O-acetylation. E. coli maltose O-acetyltransferase was demonstrated to be responsible for the mentioned regioselective O-acetylation at the 6-OH of the glucopyranosyl group of multiple classes of natural product glucosides through candidate acetyltransferase-encoding gene analysis, gene knock-out, gene complementation, and the relevant enzymatic reaction activity assays. The present study not only provides an efficient biocatalyst for regioselective O-acetylation but also notifies cautions for metabolic engineering and synthetic biology applications in E. coli. KEY POINTS: • 6-OH of glucosyl of multiple glucosides was regioselectively O-acetylated by E. coli. • Endogenous EcMAT is responsible for the regioselective O-acetylation reaction.


Assuntos
Escherichia coli , Glucosídeos , Escherichia coli/metabolismo , Glucosídeos/metabolismo , Maltose/metabolismo , Acetilação , Acetiltransferases/genética , Catálise
3.
Bioorg Chem ; 116: 105364, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34560558

RESUMO

(±)-Caryopterisines A (1) and B (2) featuring an unprecedented 6/5/5/5/6 pentacyclic rings system were isolated from Caryopteris glutinosa. The structures were determined by spectroscopic and X-ray crystallographic data analyses as well as theoretical calculations. Chiral HPLC resolution of both racemic 1 and 2 afforded their corresponding enantiotropic enantiomers. A plausible biogenesis for 1 and 2 may be originated from Diels-Alder reaction between pyridine-containing oxerine derivatives. The enantiotropic conversion mechanism of the enantiomers was demonstrated by H-D exchange and 18O incorporation studies. Compounds 1 and 2 showed moderate inhibition of estrogen E2 biosynthesis in human ovarian granulosa-like KGN cells. These two alkaloids reduced kynurenine biosynthesis at moderate level via inhibition of indoleamine 2,3-dioxygenase. Alkaloid 2 exhibited moderate inhibition of the release of interleukin-1ß.


Assuntos
Alcaloides/farmacologia , Receptor beta de Estrogênio/antagonistas & inibidores , Lamiaceae/química , Monoterpenos/farmacologia , Alcaloides/química , Alcaloides/isolamento & purificação , Linhagem Celular , Relação Dose-Resposta a Droga , Receptor beta de Estrogênio/metabolismo , Humanos , Estrutura Molecular , Monoterpenos/química , Monoterpenos/isolamento & purificação , Estereoisomerismo , Relação Estrutura-Atividade
4.
Appl Microbiol Biotechnol ; 101(10): 4053-4062, 2017 May.
Artigo em Inglês | MEDLINE | ID: mdl-28233044

RESUMO

The Camptotheca acuminata cell suspension cultures were established to produce the well-known antitumor monoterpene indole alkaloid camptothecin (CAM). Most CAM was present in the broth of the C. acuminata cell suspension cultures. The CAM production was evidenced to be attenuated when the C. acuminata cell suspension cultures were continuously subcultured and grown under identical axenic conditions. A practical cryopreservation and recovery procedure was established to maintain the C. acuminata cell suspension cultures. Biotic and abiotic elicitors were administrated to the C. acuminata cell suspension cultures to restore and enhance CAM production. Of them, sorbitol, a well-known hyperosmotic stressor, was proven to be the most effective elicitor that stimulates a ∼500-fold increase of CAM production. The committed biosynthetic precursors of CAM, tryptamine and secologanin, were feed to the C. acuminata cell suspension cultures and the CAM production is not remarkably increased. However, N 1-acetylkynuramine (NAK), an important metabolite of kynuramine pathway, was isolated and identified from the cell suspension cultures feeding with tryptamine. The present work provides an efficient method to produce CAM and NAK using the C. acuminata cell suspension cultures. The biotransformation of tryptamine to NAK sheds lights on the biosynthetic formation of the pyrroloquinoline moiety of CAM.


Assuntos
Antineoplásicos Fitogênicos/biossíntese , Camptotheca/metabolismo , Camptotecina/biossíntese , Cinuramina/análogos & derivados , Antineoplásicos Fitogênicos/análise , Antineoplásicos Fitogênicos/isolamento & purificação , Cultura Axênica , Camptotheca/efeitos dos fármacos , Camptotecina/análise , Camptotecina/isolamento & purificação , Técnicas de Cultura de Células , Criopreservação , Meios de Cultura/química , Glucosídeos Iridoides/farmacologia , Cinuramina/química , Cinuramina/metabolismo , Sorbitol/farmacologia , Triptaminas/farmacologia
5.
J Ind Microbiol Biotechnol ; 44(10): 1431-1441, 2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-28695386

RESUMO

Geranyl diphosphate (GPP), the unique precursor for all monoterpenoids, is biosynthesized from isopentenyl diphosphate and dimethylallyl diphosphate via the head-to-tail condensation reaction catalyzed by GPP synthase (GPPS). Herein a homomeric GPPS from Camptotheca acuminata, a camptothecin-producing plant, was obtained from 5'- and 3'-rapid amplification of cDNA ends and subsequent overlap extension and convenient PCR amplifications. The truncate CaGPPS was introduced to replace ispA of pBbA5c-MevT(CO)-MBIS(CO, ispA), a de novo biosynthetic construct for farnesyl diphosphate generation, and overexpressed in Escherichia coli, together with the truncate geraniol synthase-encoding gene from C. acuminata (tCaGES), to confirm CaGPPS-catalyzed reaction in vivo. A 24.0 ± 1.3 mg L-1 of geraniol was produced in the recombinant E. coli. The production of GPP was also validated by the direct UPLC-HRMSE analyses. The tCaGPPS and tCaGES genes with different copy numbers were introduced into E. coli to balance their catalytic potential for high-yield geraniol production. A 1.6-fold increase of geraniol production was obtained when four copies of tCaGPPS and one copy of tCaGES were introduced into E. coli. The following fermentation conditions optimization, including removal of organic layers and addition of new n-decane, led to a 74.6 ± 6.5 mg L-1 of geraniol production. The present study suggested that the gene copy number optimization, i.e., the ratio of tCaGPPS and tCaGES, plays an important role in geraniol production in the recombinant E. coli. The removal and addition of organic solvent are very useful for sustainable high-yield production of geraniol in the recombinant E. coli in view of that the solubility of geraniol is limited in the fermentation broth and/or n-decane.


Assuntos
Camptotheca/genética , Difosfatos/metabolismo , Diterpenos/metabolismo , Escherichia coli/genética , Escherichia coli/metabolismo , Geraniltranstransferase/genética , Geraniltranstransferase/metabolismo , Terpenos/metabolismo , Monoterpenos Acíclicos , Camptotheca/enzimologia , DNA Complementar/genética , Hemiterpenos/biossíntese , Hemiterpenos/metabolismo , Monoterpenos/metabolismo , Compostos Organofosforados/metabolismo , Fosfatos de Poli-Isoprenil/biossíntese , Reação em Cadeia da Polimerase , Sesquiterpenos
6.
J Nat Prod ; 79(4): 886-93, 2016 Apr 22.
Artigo em Inglês | MEDLINE | ID: mdl-26900877

RESUMO

Five new iridoid glucoside derivatives (1-5), three new diterpenoids (7, 12, and 15), and 11 known compounds were isolated from the aqueous EtOH extract of Caryopteris glutinosa. Cell-based estrogen biosynthesis assays indicated that caryopteriside C (3) and caryopterisoid B (12) promote the biosynthesis of estrogen E2, with EC50 values of 11.1 and 8.0 µM, respectively, in human ovarian granulosa-like KGN cells via upregulating the expression of aromatase.


Assuntos
Diterpenos/isolamento & purificação , Glucosídeos Iridoides/isolamento & purificação , Lamiaceae/química , Aromatase , Diterpenos/química , Estrogênios/metabolismo , Feminino , Humanos , Glucosídeos Iridoides/química , Estrutura Molecular , Ressonância Magnética Nuclear Biomolecular
7.
J Ind Microbiol Biotechnol ; 43(9): 1281-92, 2016 09.
Artigo em Inglês | MEDLINE | ID: mdl-27349769

RESUMO

Geraniol synthase (GES) catalyzes the conversion of geranyl diphosphate (GPP) into geraniol, an acyclic monoterpene alcohol that has been widely used in many industries. Here we report the functional characterization of CaGES from Camptotheca acuminata, a camptothecin-producing plant, and its application in production of geraniol in Escherichia coli. The full-length cDNA of CaGES was obtained from overlap extension PCR amplification. The intact and N-terminus-truncated CaGESs were overexpressed in E. coli and purified to homogeneity. Recombinant CaGES showed the conversion activity from GPP to geraniol. To produce geraniol in E. coli using tCaGES, the biosynthetic precursor GPP should be supplied and transferred to the catalytic pocket of tCaGES. Thus, ispA(S80F), a mutant of farnesyl diphosphate (FPP) synthase, was prepared to produce GPP via the head-to-tail condensation of isoprenyl diphosphate (IPP) and dimethylallyl diphosphate (DMAPP). A slight increase of geraniol production was observed in the fermentation broth of the recombinant E. coli harboring tCaGES and ispA(S80F). To enhance the supply of IPP and DMAPP, the encoding genes involved in the whole mevalonic acid biosynthetic pathway were introduced to the E. coli harboring tCaGES and the ispA(S80F) and a significant increase of geraniol yield was observed. The geraniol production was enhanced to 5.85 ± 0.46 mg L(-1) when another copy of ispA(S80F) was introduced to the above recombinant strain. The following optimization of medium composition, fermentation time, and addition of metal ions led to the geraniol production of 48.5 ± 0.9 mg L(-1). The present study will be helpful to uncover the biosynthetic enigma of camptothecin and tCaGES will be an alternative to selectively produce geraniol in E. coli with other metabolic engineering approaches.


Assuntos
Camptotheca/genética , Escherichia coli/genética , Monoéster Fosfórico Hidrolases/genética , Terpenos/metabolismo , Monoterpenos Acíclicos , Difosfatos/metabolismo , Diterpenos/metabolismo , Escherichia coli/metabolismo , Geraniltranstransferase/genética , Ácido Mevalônico/metabolismo , Monoéster Fosfórico Hidrolases/metabolismo
8.
Rapid Commun Mass Spectrom ; 29(10): 965-72, 2015 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-26407311

RESUMO

RATIONALE: Sesquiterpene pyridine alkaloids are a large group of highly oxygenated sesquiterpenoids that have attracted attention in the fields of medicine because of their significant biological activities. METHODS: Reference compounds including 14 sesquiterpene pyridine alkaloids and one dihydroagarofuran ester were analyzed by collision-induced dissociation tandem mass spectrometry (CID-MS/MS). A high-performance liquid chromatography/electrospray ionization (HPLC/ESI)-MS/MS method at two collision energies was adopted to investigate the botanical extracts of Tripterygium wilfordii. RESULTS: For 15 reference compounds, in the high mass range, the product ions were formed by the loss of side chains or H2 O. In the low mass range, the high-abundance product ions at m/z 206, 204, or 194 were the characteristic ions of the pyridine moiety. The characteristic product ion at m/z 310 was formed through an ion-neutral complex intermediate. Fifty-four sesquiterpenoid derivatives, including 50 sesquiterpene pyridine alkaloids, were identified or tentatively characterized in botanical extracts of T. wilfordii based on their elemental constituents, characteristic fragmentation patterns, and the major product ion profiles of the reference compounds ascertained with HPLC/ESI-MS/MS at two collision energies. It seems that isocratic energy was appropriate for the untargeted analysis of compounds with molecular weights exceeding 800 Da, whereas a linear gradient energy vs molecular weight was suitable for those compounds with molecular weights below 800 Da. CONCLUSIONS: The HPLC/ESI-MS/MS method, combining characteristic fragmentation patterns and the profiles of the product ions generated at different collision energies, is an effective technique for characterizing untargeted compounds.


Assuntos
Alcaloides/análise , Piridinas/análise , Sesquiterpenos/análise , Tripterygium/química , Cromatografia Líquida de Alta Pressão/métodos , Espectrometria de Massas por Ionização por Electrospray/métodos , Espectrometria de Massas em Tandem/métodos
9.
J Ind Microbiol Biotechnol ; 42(8): 1197-202, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-26124076

RESUMO

Camptothecin (CPT) is mainly produced and extracted from Camptotheca acuminata and Nothapodytes foetida for pharmaceutical use, i.e., the starting material for chemical conversion to the clinical CPT-type drugs. As the third largest plant anticancer drug, the heavy demand on CPT from global market leads to many research efforts to identify new sources for CPT production. Herein we report the isolation and characterization of a CPT-producing endophytic bacterium Paenibacillus polymyxa LY214 from Camptotheca acuminata. A 10.7 µg l(-1) of CPT was presented in the fermentation broth of P. polymyxa LY214. Its CPT production decreased sharply when the strain of the 2nd generation of P. polymyxa LY214 was cultured and fermented. However, the CPT production remained relatively constant from 2.8 µg l(-1) of the 2nd generation to 0.8 µg l(-1) of the 8th generation of P. polymyxa LY214 under optimized fermentation conditions. A 15- to 30-fold increase of CPT yield was observed when the optimized fermentation conditions, together with the addition of putative biosynthetic precursors of CPT and adsorbent resin XAD16, were applied to ferment the strains of the 7th and 8th generation of P. polymyxa LY214. Bioinformatics analysis of the relative species of P. polymyxa LY214 indicates its potential to produce CPT, which will be helpful to decipher the mysteries of CPT biosynthesis.


Assuntos
Camptotheca/microbiologia , Camptotecina/biossíntese , Paenibacillus/isolamento & purificação , Antineoplásicos Fitogênicos/biossíntese , Camptotheca/química , Fermentação , Magnoliopsida , Paenibacillus/genética , Paenibacillus/metabolismo
10.
J Asian Nat Prod Res ; 17(3): 248-55, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25424560

RESUMO

Activity-guided fractionation of Neosinocalamus affinis leaves led to obtain two new flavonoids, 4'-O-((7″R,8″S)-8″-guaiacylglyceryl)-pleioside B (9) and apigenin 6-C-ß-d-fucopyranosyl-7-O-ß-d-glucopyranoside (10) along with eight known compounds. Their structures were elucidated on the basis of spectroscopic data (UV, IR, NMR, and MS). Among these 10 compounds, farobin A (4) and isoorientin (7) showed significant antioxidant activity evaluated by 1,1-diphenyl-2-picrylhydrazyl, 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid), superoxide anion and nitric oxide (NO) radical-scavenging assays.


Assuntos
Antioxidantes/isolamento & purificação , Antioxidantes/farmacologia , Flavonoides/isolamento & purificação , Flavonoides/farmacologia , Sasa/química , Antioxidantes/química , Benzotiazóis/química , Compostos de Bifenilo/farmacologia , Etanol , Flavonoides/química , Sequestradores de Radicais Livres/química , Estrutura Molecular , Picratos/farmacologia , Folhas de Planta/química , Ácidos Sulfônicos/química , Superóxidos/análise
11.
J Nat Prod ; 77(7): 1650-7, 2014 Jul 25.
Artigo em Inglês | MEDLINE | ID: mdl-24963543

RESUMO

Thunder god vine, the dried roots of Tripterygium wilfordii, is a widely used traditional Chinese medicine. More than 200 bioactive complex natural products have been isolated from this herb. Inspired by the diversity of chemical structures and bioactivities of the components of this herb, the investigation to mine new chemical entities as potential drug leads led to the identification of 36 nitrogen-containing compounds. Among them, 18 new dihydro-ß-agarofuran alkaloids (tripterygiumines A-L (1-12), M-Q (22-26), and R (33)) were identified from the spectroscopic data and chemical degradation studies. Tripterygiumine Q (26) exhibited immunosuppressive activity against human peripheral mononuclear cells with an IC50 value of 8.67 µM and showed no cytotoxicity, even at 100 µM, indicating that 26 may represent a novel scaffold for the development of new immunosuppressants.


Assuntos
Alcaloides/isolamento & purificação , Medicamentos de Ervas Chinesas/isolamento & purificação , Imunossupressores/isolamento & purificação , Nitrogênio/química , Alcaloides/química , Alcaloides/farmacologia , Medicamentos de Ervas Chinesas/química , Humanos , Imunossupressores/química , Imunossupressores/farmacologia , Concentração Inibidora 50 , Medicina Tradicional Chinesa , Estrutura Molecular , Ressonância Magnética Nuclear Biomolecular , Raízes de Plantas/química , Tripterygium/química
12.
Appl Microbiol Biotechnol ; 97(21): 9365-75, 2013 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-23949997

RESUMO

Camptothecin (CPT), the third largest anticancer drug, is produced mainly by Camptotheca acuminata and Nothapodytes foetida. CPT itself is the starting material for clinical CPT-type drugs, but the plant-derived CPT cannot support the heavy demand from the global market. Research efforts have been made to identify novel sources for CPT. In this study, three CPT-producing endophytic fungi, Aspergillus sp. LY341, Aspergillus sp. LY355, and Trichoderma atroviride LY357, were isolated and identified from C. acuminata. Most CPT produced by these fungi was found in the fermentation broth, and their corresponding CPT yields were 7.93, 42.92, and 197.82 µg l(-1), respectively. The CPT-producing capability of LY341 and LY355 was completely lost after repeat subculturing. A substantial decrease of CPT production was also observed in the second generation of LY357. However, a stable and sustainable production of CPT was found from the second generation through the eighth generation of LY357. The fermentation medium, time, pH, temperature, and agitation rate were optimized for CPT production. Methyl jasmonate and XAD16 were proven to be an optimum elicitor and adsorbent resin, respectively, in view of that CPT yield was increased 3.4- and 11-fold through their use. A 50- to 75-fold increase of CPT yield was obtained when the optimized fermentation conditions, elicitor, and adsorbent resin were combined and applied to the culture of the seventh and eighth generations of LY357, and the highest CPT yield was 142.15 µg l(-1). The CPT-producing T. atroviride LY357 paves a potential to uncover the mysteries of CPT biosynthesis.


Assuntos
Antineoplásicos/metabolismo , Camptotecina/metabolismo , Endófitos/isolamento & purificação , Endófitos/metabolismo , Trichoderma/isolamento & purificação , Trichoderma/metabolismo , Aspergillus/classificação , Aspergillus/genética , Aspergillus/isolamento & purificação , Aspergillus/metabolismo , Camptotheca/microbiologia , Meios de Cultura/química , DNA Fúngico/química , DNA Fúngico/genética , Endófitos/classificação , Endófitos/genética , Fermentação , Concentração de Íons de Hidrogênio , Dados de Sequência Molecular , Análise de Sequência de DNA , Temperatura , Fatores de Tempo , Trichoderma/classificação , Trichoderma/genética
13.
Phytochemistry ; 213: 113752, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37330032

RESUMO

Four undescribed tryptamine-derived alkaloids, hunteriasines A - D, were isolated and identified from Hunteria umbellata (Apocynaceae), together with fifteen known indole alkaloids. The chemical structure and absolute configuration of hunteriasine A were determined by spectroscopic and X-ray crystallographic data analyses. Hunteriasine A, featuring with a unique scaffold comprised of tryptamine and an unprecedented "12-carbon unit" moiety, is a zwitterionic indole-derived and pyridinium-containing alkaloid. Hunteriasines B - D were identified by spectroscopic data analyses and theoretical calculations. A plausible biogenetic pathway for hunteriasines A and B was proposed. The lipopolysaccharide-stimulated mouse macrophage cell line J774A.1 cell-based bioactivity assays revealed that (+)-eburnamine, strictosidinic acid, and (S)-decarbomethoxydihydrogambirtannine enhance the release of interleukin-1ß.


Assuntos
Alcaloides , Apocynaceae , Alcaloides de Triptamina e Secologanina , Camundongos , Animais , Alcaloides/farmacologia , Alcaloides Indólicos/farmacologia , Alcaloides Indólicos/química , Apocynaceae/química , Extratos Vegetais/química , Triptaminas/farmacologia , Estrutura Molecular , Alcaloides de Triptamina e Secologanina/química
14.
ACS Infect Dis ; 9(4): 785-800, 2023 04 14.
Artigo em Inglês | MEDLINE | ID: mdl-37005772

RESUMO

Fungal infections caused by opportunistic pathogens, such as Candida albicans, are generally underappreciated by the public in spite of their high mortality rates. Antifungal arsenals are extremely limited. Herein, based on biosynthetic pathway comparison and functional characterization, CaERG6, a crucial sterol 24-C-methyltransferase involved in the biosynthesis of ubiquitous ergosterol in C. albicans, was set up as an antifungal target. CaERG6 inhibitors were identified from the in-house small-molecule library by a biosensor-based high-throughput screening. The CaERG6 inhibitor NP256 (palustrisoic acid E) is a potential antifungal natural product that acts by inhibiting ergosterol biosynthesis, downregulating the gene expression level in hyphal formation, blocking biofilm formation, and disrupting morphological transition in C. albicans. NP256 enhances C. albicans susceptibility to some known antifungals significantly. The present study demonstrated the CaERG6 inhibitor NP256 as a potential class of antifungal compound for monotherapy or combinatory therapy.


Assuntos
Antifúngicos , Candida albicans , Antifúngicos/farmacologia , Antifúngicos/uso terapêutico , Ensaios de Triagem em Larga Escala , Ergosterol
15.
J Nat Prod ; 75(1): 98-102, 2012 Jan 27.
Artigo em Inglês | MEDLINE | ID: mdl-22148431

RESUMO

Five new sesquiterpene derivatives, including dihydroagarofuran pyridine macrolides 1-4 and dihydroagarofuran ester 18, and 13 known dihydroagarofuran derivatives were isolated from the aqueous EtOH extract of the dried roots of Tripterygium wilfordii. An in vitro antiherpetic activity assay indicated that compounds 11 and 17 displayed weak and moderate inhibition against herpes simplex virus type II, respectively.


Assuntos
Alcaloides/isolamento & purificação , Antivirais/isolamento & purificação , Medicamentos de Ervas Chinesas/isolamento & purificação , Macrolídeos/isolamento & purificação , Sesquiterpenos/isolamento & purificação , Tripterygium/química , Aciclovir/farmacologia , Alcaloides/química , Alcaloides/farmacologia , Antivirais/química , Antivirais/farmacologia , Medicamentos de Ervas Chinesas/química , Medicamentos de Ervas Chinesas/farmacologia , Herpes Simples/tratamento farmacológico , Herpesvirus Humano 2/efeitos dos fármacos , Macrolídeos/química , Macrolídeos/farmacologia , Estrutura Molecular , Raízes de Plantas/química , Sesquiterpenos/química , Sesquiterpenos/farmacologia
16.
Phytochemistry ; 203: 113378, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-36007661

RESUMO

Three undescribed dimeric pyridine-containing alkaloids, caryopterisines C - E, and four unreported cyclopenta[c]pyridine-derived alkaloids, caryopterisines F - I, were identified from Caryopteris glutinosa Rehder (Lamiaceae), together with two known monoterpene alkaloids. Caryopterisine C, featuring with an unprecedented 6/5/6/6/5 pentacyclic rings scaffold, may biosynthetically stem from a Diels-Alder reaction of two cyclopenta[c]pyridine-containing monomers and a following aromatization rearrangement reaction. Caryopterisines D and E, possessing an unprecedented 6/6/6/6/5 fused rings framework, may originate from a same Diels-Alder reaction of two monomers and subsequent aromatization arrangement, Baeyer-Villiger oxidation, and a set of tailoring reactions. Caryopterisine C showed strong inhibition on collagen accumulation in NIH3T3 cells (IC50 = 14.26 ± 1.46 µM). Caryopterisines G and I reduce collagen accumulation with IC50 values 88.91 ± 0.95 µM and 33.09 ± 1.38 µM, respectively. The Western blotting of the transforming growth factor-ß-activated signaling pathways revealed that caryopterisine C inhibits collagen expression and accumulation via suppression of the phosphorylation of ERK1/2, P38, and SMAD2/3. The present works indicate caryopterisine C is a potential lead compound for the development of antifibrotic drugs.


Assuntos
Alcaloides , Lamiaceae , Alcaloides/farmacologia , Animais , Colágeno/metabolismo , Lamiaceae/metabolismo , Camundongos , Monoterpenos/farmacologia , Células NIH 3T3 , Piridinas , Fatores de Crescimento Transformadores
17.
Front Plant Sci ; 13: 987348, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36061783

RESUMO

Tryptophan decarboxylases (TDCs) are a group of pyridoxal 5'-phosphate-dependent enzymes involved in the enzymatic conversion of tryptophan into tryptamine, a critical biogenic amine. We herein mined and cloned a TDC-encoding gene, CaTDC3, from camptothecin-producing plant Camptotheca acuminata. The intact CaTDC3 was heterologously overexpressed in Escherichia coli and the recombinant CaTDC3 was purified to homogeneity. High-performance liquid chromatography (HPLC)-diode array detector (DAD) and high resolution mass spectrometry (HRMS) data analyses of the CaTDC3-catalyzed reaction mixture confirmed the catalytically decarboxylative activity of CaTDC3. CaTDC3 shows strict stereoselectivity for L-tryptophan. Homology modeling and molecular docking implied CaTDC3's recognition of L-tryptophan derivatives and analogs. Substrate scope investigations revealed that the appropriate substituent groups on the indole ring, i.e., hydroxylated and halogenated L-tryptophans, could be recognized by CaTDC3 and the decarboxylation reactions generated the corresponding tryptamines. The Cß -methyl-L-tryptophans were decarboxylated by CaTDC3 efficiently. 1-Thio-L-tryptophan, the NH group of the indole ring replaced by an S atom, could be decarboxylated by CaTDC3. CaTDC3 catalyzed the decarboxylation of 7-aza-L-tryptophan, an N displacement of the C on the aromatic ring, to afford 7-aza-tryptamine. L-Kynurenine, an L-tryptophan degradation product, could be decarboxylated by CaTDC3. The present works uncover a catalytically promiscuous TDC and the TDC is a versatile decarboxylase in synthetic biology for specialized pharmaceutically important substances.

18.
Front Plant Sci ; 13: 851077, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35401649

RESUMO

Treatments with abiotic elicitors can efficiently induce the accumulation of specialized metabolites in plants. We used a combined omics approach to analyze the elicitation effects of MeJa, AgNO3, and PEG on camptothecin (CPT) biosynthesis in Camptotheca acuminata plantlets. Untargeted analyses revealed that treatments with MeJa, AgNO3, and PEG significantly inhibited the photosynthetic pathway and promoted carbon metabolism and secondary metabolic pathways. The CPT levels increased by 78.6, 73.3, and 50.0% in the MeJa, AgNO3, and PEG treatment groups, respectively. Using C. acuminata plantlets after elicitation treatment, we mined and characterized 15 new alkaloids, 25 known CPT analogs and precursors, 9 iridoid biosynthetic precursors, and 15 tryptamine biosynthetic precursors based on their MS/MS fragmentation spectra. Using 32 characterized genes involved in CPT biosynthesis as bait, we mined 12 prioritized CYP450 genes from the 416 CYP450 candidates that had been identified based on co-expression analysis, conserved domain analysis, and their elicitation-associated upregulation patterns. This study provides a comprehensive perspective on CPT biosynthesis in C. acuminata plantlets after abiotic elicitation. The findings enable us to elucidate the previously unexplored CYP450-mediated oxidation steps for CPT biosynthesis.

19.
Planta Med ; 77(18): 2047-9, 2011 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-21858759

RESUMO

Guided by lipid-lowering assays, a new compound (1, 2-phenylethyl 2,6-dihydroxybenzoate) was isolated from the ethanolic extract of Geophila herbacea. The structure of 1 was determined unambiguously by spectral data interpretation and confirmed by X-ray crystallographic analysis. Preliminary dose-dependency of 1 verified its lipid-lowering bioactivity in vitro. A facile chemical synthesis for 1 was performed to provide a practical approach for further studies on structure-activity relationship.


Assuntos
Hidroxibenzoatos/isolamento & purificação , Hidroxibenzoatos/farmacologia , Hipolipemiantes/isolamento & purificação , Hipolipemiantes/farmacologia , Cristalografia por Raios X , Etanol/química , Células Hep G2 , Humanos , Hidroxibenzoatos/síntese química , Hidroxibenzoatos/química , Hipolipemiantes/síntese química , Hipolipemiantes/química , Estrutura Molecular , Extratos Vegetais/química , Rubiaceae/química , Espectrometria de Massas por Ionização por Electrospray/métodos , Relação Estrutura-Atividade
20.
Zhongguo Zhong Yao Za Zhi ; 36(10): 1337-41, 2011 May.
Artigo em Zh | MEDLINE | ID: mdl-21837979

RESUMO

Typhonii Rhizoma is a toxic traditional Chinese medicine. Its toxic components remained unclear. To compare chemical composition of volatile oils from fresh and processed Typhonii Rhizoma qualitatively, volatile oils were obtained by stream distillation and analyzed by GC-MS. The data obtained from GC-MS were processed by principal component analysis. From the essential oils of fresh and processed Typhonii Rhizoma, 43 compounds and 34 compounds were identified respectively. The chemical composition and content in the two oils was different. In the two essential oils 15 identical components were detected. The chemical components and their contents in the essential oils are changing with the storage.


Assuntos
Araceae/química , Medicamentos de Ervas Chinesas/química , Cromatografia Gasosa-Espectrometria de Massas/métodos , Óleos Voláteis/química
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