trametenolic-acid-b and Adenocarcinoma

Two new lanostane-type triterpenoids, inonotsuoxides A (1) and B (2) along with three known lanostane-type triterpenoids, inotodiol (3), trametenolic acid (4), and lanosterol (5), were isolated from the sclerotia of Inonotus obliquus (Pers.: Fr.) (Japanese name: Kabanoanakake) (Russian name: Chaga). Their structures were determined to be 22R,25-epoxylanost-8-ene-3beta,24S-diol (1) and 22S,25-epoxylanost-8-ene-3beta,24S-diol (2) on the basis of spectral data including single crystal X-ray analysis. These compounds except for 2 were tested for their inhibitory effects on Epstein-Barr virus early antigen (EBV-EA) activation induced by 12-O-tetradecanoylphorbol-13-acetate (TPA), as a test for potential cancer chemopreventive agents. The most abundant triterpene, inotodiol (3), was investigated for the inhibitory effect in a two-stage carcinogenesis test on mouse skin using 7,12-dimethylbenz[a]anthracene (DMBA) as an initiator and TPA as a promoter. Compound 3 was found to exhibit the potent anti-tumor promoting activity in the in vivo carcinogenesis test.

Topics: 9,10-Dimethyl-1,2-benzanthracene; Adenocarcinoma; Animals; Antigens, Viral; Antineoplastic Agents; Basidiomycota; Cell Line, Tumor; Crystallography, X-Ray; Drug Screening Assays, Antitumor; Female; Lanosterol; Magnetic Resonance Spectroscopy; Mice; Mice, Inbred ICR; Models, Molecular; Molecular Conformation; Plant Extracts; Reference Standards; Stereoisomerism; Structure-Activity Relationship; Tetradecanoylphorbol Acetate; Triterpenes; Xenograft Model Antitumor Assays