title: Antibacterial anthraquinone derivatives from a sea anemone-derived fungus Nigrospora sp.
abstract: Chemical investigation of a marine-derived fungus Nigrospora sp., isolated from an unidentified sea anemone, yielded two new hydroanthraquinone analogues, 4a-epi-9α-methoxydihydrodeoxybostrycin (1) and 10-deoxybostrycin (2), together with seven known anthraquinone derivatives (3-9). The structures of the two new compounds were established through extensive NMR spectroscopy as well as a single-crystal X-ray diffraction analysis using Cu Kα radiation. The antibacterial activities of compounds 1-9 and 10 acetyl derivatives (6a, 7a, 8a-8g, 9a) were evaluated in vitro. Compound 6a, the acetylated derivative of 6, exhibited promising activity against Bacillus cereus with an MIC value of 48.8 nM, which was stronger than that of the positive control ciprofloxacin (MIC = 1250 nM). Analysis of the antibacterial screening data for the metabolites and their acetyl derivatives revealed the key structural features required for this activity.
authors.affiliation: Key Laboratory of Marine Drugs, The Ministry of Education of China, School of Medicine and Pharmacy,  Ocean University of China , Qingdao 266003, People's Republic of China.
authors.forename: Kai-Lin
authors.initials: KL
authors.lastname: Yang
authors.forename: Mei-Yan
authors.initials: MY
authors.lastname: Wei
authors.forename: Chang-Lun
authors.initials: CL
authors.lastname: Shao
authors.forename: Xiu-Mei
authors.initials: XM
authors.lastname: Fu
authors.forename: Zhi-Yong
authors.initials: ZY
authors.lastname: Guo
authors.forename: Ru-Fang
authors.initials: RF
authors.lastname: Xu
authors.forename: Cai-Juan
authors.initials: CJ
authors.lastname: Zheng
authors.forename: Zhi-Gang
authors.initials: ZG
authors.lastname: She
authors.forename: Yong-Cheng
authors.initials: YC
authors.lastname: Lin
authors.forename: Chang-Yun
authors.initials: CY
authors.lastname: Wang
mesh_terms: D000818:Animals; D000880:Anthraquinones / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D000900:Anti-Bacterial Agents / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D001203:Ascomycota / Q000737:chemistry*; D001412:Bacillus subtilis / Q000187:drug effects; D002939:Ciprofloxacin / Q000494:pharmacology; D018360:Crystallography, X-Ray; D004926:Escherichia coli / Q000187:drug effects; D008386:Marine Biology; D008826:Microbial Sensitivity Tests; D016982:Micrococcus luteus / Q000187:drug effects; D015394:Molecular Structure; D012615:Sea Anemones / Q000382:microbiology*; D013211:Staphylococcus aureus / Q000187:drug effects
chemical_list: D000880:Anthraquinones; D000900:Anti-Bacterial Agents; D002939:Ciprofloxacin