JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY
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2020
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IF 4.192
Yu-Qi Gao,Shuang-Tian Du,Jian Xiao,Da-Cheng Wang,Wen-Bo Han,Qiang Zhang,Jin-Ming Gao
Two biosynthetically related new metabolites, eucalyptacid A (1) and eucalactam B (2), along with six known compounds (3–8), eugenitol (3), cytosporone C (4), 4-hydroxyphenethyl alcohol (5), 1-(4-hydroxyphenyl)ethane-1,2-diol (6), N-(2-hydroxy-2-phenylethyl)acetamide (7), and phomopene (8), were isolated from the solid rice cultures of the endophytic fungus Diaporthe eucalyptorum KY-9 that had been isolated from Melia azedarach. Also, two further new derivatives (2a, 2b) were prepared from 2. The structures were elucidated by exhaustive analysis of NMR and ESIMS data and chemical methods such as Marfey’s protocol. Compound 1 was identified as a rare polyketide fatty acid, (8E)-3,5,11-trihydroxy-2,10,12-trimethyltetradecenoic acid, and 2 was determined to be the first cyclic depsipeptide containing the same fatty acid unit as 1 and a Gly-Gly-Thr tripeptide chain. Its N-terminal end is N-acylated by an 11-hydroxy fatty acid with a branch alkyl chain of 14:1. The 11-hydroxyl group connects to the carboxylic group of the C-terminal amino acid to form a 22-membered lactone ring. A hypothetical biosynthetic pathway for the new polyketides is proposed. The isolated compounds were assayed for their inhibition against four plant pathogenic fungi, Alternaria solani, Botrytis cinerea, Fusarium solani, and Gibberella saubinettii. Compounds 1, 4, 6, and 7 exhibited antifungal activities against Alternaria solani, with minimal inhibitory concentration (MIC) values from 6.25 to 50 μM. Thus, strain KY-9 represents an untapped source for the development of biological control agents to prevent the infection of pathogenic fungus A. solani.
研究领域:
植物学
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微生物学
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药理学
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DOI
PubMed
高影响因子
JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY
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2014
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IF 3.107
Jian Xiao,Qiang Zhang,Yu-Qi Gao,Jiang-Jiang Tang,An-Ling Zhang,Jin-Ming Gao
Two new metabolites, an α-pyridone derivative, 3-hydroxy-2-methoxy-5-methylpyridin-2(1H)-one (1), and a ceramide derivative, 3-hydroxy-N-(1-hydroxy-3-methylpentan-2-yl)-5-oxohexanamide (2), and a new natural product, 3-hydroxy-N-(1-hydroxy-4-methylpentan-2-yl)-5-oxohexanamide (3), along with 15 known compounds including chaetoglobosin C (7) and chaetoglobosin F (8) were isolated from the solid culture of the endophytic fungus Botryosphaeria dothidea KJ-1, collected from the stems of white cedar (Melia azedarach L). The structures were elucidated on the basis of spectroscopic analysis (1D and 2D NMR experiments and by mass spectrometric measurements), and the structure of 1 was confirmed by X-ray single-crystal diffraction. These metabolites were evaluated in vitro for antimicrobial, antioxidant, and cytotoxicity activities. Pycnophorin (4) significantly inhibited the growth of Bacillus subtilis and Staphyloccocus aureus with equal minimum inhibitory concentration (MIC) values of 25 μM. Stemphyperylenol (5) displayed a potent antifungal activity against the plant pathogen Alternaria solani with MIC of 1.57 μM comparable to the commonly used fungicide carbendazim. Both altenusin (9) and djalonensone (10) showed markedly DPPH radical scavenging activities. In addition, stemphyperylenol (5) and altenuene (6) exhibited strong cytotoxicity against HCT116 cancer cell line with a median inhibitory concentration (IC50) value of 3.13 μM in comparison with the positive control etoposide (IC50 = 2.13 μM). This is the first report of the isolation of these compounds from the endophytic B. dothidea.
研究领域:
药理学
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微生物学
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生物化学
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有机化学
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植物科学
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DOI
PubMed
高影响因子
JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY
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2012
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IF 2.823
Xiao-Jun Li,Qiang Zhang,An-Ling Zhang,Jin-Ming Gao
Thirty-nine fungal metabolites 1–39, including two new alkaloids, 12β-hydroxy-13α-methoxyverruculogen TR-2 (6) and 3-hydroxyfumiquinazoline A (16), were isolated from the fermentation broth of Aspergillus fumigatus LN-4, an endophytic fungus isolated from the stem bark of Melia azedarach. Their structures were elucidated on the basis of detailed spectroscopic analysis (mass spectrometry and one- and two-dimensional NMR experiments) and by comparison of their NMR data with those reported in the literature. These isolated compounds were evaluated for in vitro antifungal activities against some phytopathogenic fungi, toxicity against brine shrimps, and antifeedant activities against armyworm larvae (Mythimna separata Walker). Among them, sixteen compounds showed potent antifungal activities against phytopathogenic fungi (Botrytis cinerea, Alternaria solani, Alternaria alternata, Colletotrichum gloeosporioides, Fusarium solani, Fusarium oxysporum f. sp. niveum, Fusarium oxysporum f. sp. vasinfectum, and Gibberella saubinettii), and four of them, 12β-hydroxy-13α-methoxyverruculogen TR-2 (6), fumitremorgin B (7), verruculogen (8), and helvolic acid (39), exhibited antifungal activities with MIC values of 6.25–50 μg/mL, which were comparable to the two positive controls carbendazim and hymexazol. In addition, of eighteen that exerted moderate lethality toward brine shrimps, compounds 7 and 8 both showed significant toxicities with median lethal concentration (LC50) values of 13.6 and 15.8 μg/mL, respectively. Furthermore, among nine metabolites that were found to possess antifeedant activity against armyworm larvae, compounds 7 and 8 gave the best activity with antifeedant indexes (AFI) of 50.0% and 55.0%, respectively. Structure–activity relationships of the metabolites were also discussed.
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高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
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2025
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IF 8.5
Xinyao Su,Jia Liu,Jiarou Liu,Qiang Xue,Caixia Wang
Melia azedarach L. serves as an important source of timber and bioactive triterpenoids, notably tetracyclic limonoids and pharmacologically active pentacyclic triterpenes such as β-amyrin derivatives. Although limonoid biosynthesis has been extensively characterized, the enzymatic machinery governing pentacyclic triterpene formation remains poorly defined. Through transcriptomic mining of M. azedarach , we identified three CYP88A subfamily cytochrome P450 genes ( MaCYP88A108 , MaCYP88A164 , and MaCYP88A222 ). Functional characterization in both Nicotiana benthamiana transient expression systems and yeast microsomes demonstrated their catalytic roles as β-amyrin 11-oxidases, sequentially converting β-amyrin to 11-oxo-β-amyrin via C-11 oxidation. Intriguingly, MaCYP88A108 and MaCYP88A164 exhibited dual functionality, participating not only in pentacyclic triterpene production but also in limonoid biosynthesis, suggesting their evolutionary recruitment for triterpenoid diversification. Phylogenetic reconstruction and structural modeling revealed that these CYP88A enzymes share close homology and conserved active-site architectures with Glycyrrhiza uralensis CYP88D6 (GuCYP88D6), a characterized β-amyrin 11-oxidase, despite lacking genomic synteny. This observation supports a paradigm of functional convergence driven by structural conservation rather than shared gene lineage. Furthermore, we characterized an oxidosqualene cyclase ( MaβAS1 ) responsible for cyclizing 2,3-oxidosqualene to β-amyrin, thereby establishing the substrate pool for downstream oxidation. Our study uncovers a unique catalytic versatility in plant CYP88A P450s, demonstrating their capacity to coordinate two divergent triterpenoid branches. This functional plasticity, mediated by evolutionarily conserved structural frameworks, expands current paradigms of enzyme multifunctionality in plant specialized metabolism. The identified genes ( CYP88As and MaβAS1 ) establish critical tools for synthetic biology platforms targeting heterologous production of pharmaceutically important triterpenoids, bridging mechanistic exploration of plant secondary metabolism with biotechnological applications.
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PubMed
高影响因子
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