title: Cytotoxic steroids from Monascus purpureus-fermented rice.
abstract: Bioassay-guided fractionation of an EtOH extract of Monascus purpureus-fermented rice led to the isolation of two new steroids (22S, 23R, 24S)-20β,23α,25α-trihydroxy-16,22-epoxy-4,6,8(14)-trienergosta-3-one (1), the first example of a steroid possessing both a conjugated triene ketone system and a fused 4H-furan ring side chain within one molecule, and (22E, 24R)-3β,5α-dihydroxyergosta-23-methyl-7,22-dien-6-one (2), as well as two known compounds (22E, 24R)-3β,5α-dihydroxyergosta-7,22-dien-6-one (3) and (22E, 24R)-6β-methoxy-ergosta-7,22-diene-3β,5α-diol (4). Their structures were assigned by detailed interpretation of HRESIMS, 1D and 2D NMR spectroscopic data. The absolute stereochemistry of 1 was determined by single-crystal X-ray crystallography while the absolute stereochemistry of 2 was established by CD. Compounds 1-4 showed cytotoxic activity against the lung adenocarcinoma (A549) with IC(50) values of 0.08, 0.94, 12.6 and 13.5 μM, respectively. In addition, compounds 1 and 2 exhibited moderate activities against human ovarian cancer (A2780), with IC(50) values of 2.8 and 5.1 μM.
authors.affiliation: Beijing Union University, Beijing Key Laboratory of Bioactive Substances and Functional Foods, 197# Beitucheng West Road, Haidian District, Beijing 100191, PR China. shangxiaoya@ygi.edu.cn
authors.forename: Xiao-Ya
authors.initials: XY
authors.lastname: Shang
authors.forename: Jin-Jie
authors.initials: JJ
authors.lastname: Li
authors.forename: Ming-Tao
authors.initials: MT
authors.lastname: Liu
authors.forename: Shuai
authors.initials: S
authors.lastname: Li
authors.forename: Ying
authors.initials: Y
authors.lastname: Liu
authors.forename: Ye-Feng
authors.initials: YF
authors.lastname: Wang
authors.forename: Xiao
authors.initials: X
authors.lastname: Huang
authors.forename: Zong-Lian
authors.initials: ZL
authors.lastname: Jin
mesh_terms: D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects; D018360:Crystallography, X-Ray; D005285:Fermentation; D006801:Humans; D009682:Magnetic Resonance Spectroscopy; D015394:Molecular Structure; D032741:Monascus / Q000378:metabolism*; D012275:Oryza / Q000737:chemistry* / Q000382:microbiology; D013256:Steroids / Q000737:chemistry* / Q000494:pharmacology*
chemical_list: D013256:Steroids