title: Secondary metabolites from the endophytic Botryosphaeria dothidea of Melia azedarach and their antifungal, antibacterial, antioxidant, and cytotoxic activities.
abstract: 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.
authors.affiliation: Shaanxi Engineering Center of Bioresource Chemistry and Sustainable Utilization, College of Science, Northwest A&F University , Yangling 712100, Shaanxi China.
authors.forename: Jian
authors.initials: J
authors.lastname: Xiao
authors.forename: Qiang
authors.initials: Q
authors.lastname: Zhang
authors.forename: Yu-Qi
authors.initials: YQ
authors.lastname: Gao
authors.forename: Jiang-Jiang
authors.initials: JJ
authors.lastname: Tang
authors.forename: An-Ling
authors.initials: AL
authors.lastname: Zhang
authors.forename: Jin-Ming
authors.initials: JM
authors.lastname: Gao
mesh_terms: D000900:Anti-Bacterial Agents / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology*; D000975:Antioxidants / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology*; D001203:Ascomycota / Q000737:chemistry* / Q000378:metabolism; D001419:Bacteria / Q000187:drug effects; D045744:Cell Line, Tumor; D003603:Cytotoxins / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology*; D060026:Endophytes / Q000737:chemistry* / Q000378:metabolism; D005658:Fungi / Q000187:drug effects; D005659:Fungicides, Industrial / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology*; D006801:Humans; D031586:Melia azedarach / Q000382:microbiology*; D008826:Microbial Sensitivity Tests; D064210:Secondary Metabolism
chemical_list: D000900:Anti-Bacterial Agents; D000975:Antioxidants; D003603:Cytotoxins; D005659:Fungicides, Industrial