title: Three novel, structurally unique spirocyclic alkaloids from the halotolerant B-17 fungal strain of Aspergillus variecolor.
abstract: During our search for novel antitumor lead compounds from microorganisms living under extreme conditions, three novel alkaloids, variecolortides A-C (1-3), were isolated from the mycelia of the halotolerant fungal strain Aspergillus variecolor B-17. The new compounds were found to share an unprecedented 'spiro-anthronopyranoid diketopiperazine' structure, with a stable hemiaminal function, as corroborated by in-depth NMR-spectroscopic and mass-spectrometric analyses, as well as by a single-crystal X-ray analysis of 1. All compounds were shown to exhibit weak cytotoxic and antioxidant activities.
authors: Key Laboratory of Marine Drugs, Chinese Ministry of Education, School of Medicine and Pharmacy, Ocean University of China, Qingdao 266003, PR China.
authors: Wen-Liang
authors: WL
authors: Wang
authors: Tian-Jiao
authors: TJ
authors: Zhu
authors: Hong-Wen
authors: HW
authors: Tao
authors: Zhen-Yu
authors: ZY
authors: Lu
authors: Yu-Chun
authors: YC
authors: Fang
authors: Qian-Qun
authors: QQ
authors: Gu
authors: Wei-Ming
authors: WM
authors: Zhu
mesh_terms: D000470:Alkaloids / Q000737:chemistry* / Q000302:isolation & purification* / Q000633:toxicity; D001230:Aspergillus / Q000737:chemistry* / Q000145:classification; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects; D004351:Drug Resistance / Q000187:drug effects*; D006801:Humans; D047028:Macrocyclic Compounds / Q000737:chemistry* / Q000633:toxicity; D009682:Magnetic Resonance Spectroscopy; D008958:Models, Molecular; D015394:Molecular Structure; D009369:Neoplasms / Q000473:pathology; D012492:Salts / Q000494:pharmacology*; D013141:Spiro Compounds / Q000737:chemistry* / Q000633:toxicity
chemical_list: D000470:Alkaloids; D047028:Macrocyclic Compounds; D012492:Salts; D013141:Spiro Compounds