Studies On The Antimutagenic Constituents Of Inonotus Obliquus

With the deteriorating of environmental pollution in the more industrialized world, the environment mutagens and carcinogens are threatening our health more seriously. Antimutagents can prevent genemutaion-causing diseases. It has been a hot topic for the scholars at home and abroad to search for antimutagenic comstituents from natural plants.Inonotus obliquus (Pers. :Fr.) Pilat has been used for many kinds of tumors for a long time in many countries. It was reported that the aqueous extract of Inonotus obliquus inhibited the growth of sarcoma in mice. Antitumor activity of some compounds and fractions from an n-hexane extract of I. obliquus was tested against Walker 256 carcinosarcoma and MCF-7 human mammary adenocarcinoma in vitro, and leukemia P 388 in vivo. Inotodiol from I. obliquus was proved to be as strongly active as the mixture of 3 β ,22-dihydroxy-lanosta-8,24-dien-7-one and 3 3 ,22-dihydroxy-lanosta-7,6(11),24-triene. But study of antimutagenic activity of/. obliquus was accordingly not reported.In order to search for and make sure its antimutagenic constituents, petroleum ether extract, ethyl acetate extract, n-Butanol extract and crude polysaccharide of /. obliquus were firstly screened by Ames test. And then the antimutagenic extracts were further chromatographed to obtain the active compounds.The results showed: (1) The petroleum ether and ethyl acetate extracts both showed high inhibition rate to Salmonella typhimurium strains TA100, as the antimutagenic extracts. (2) Seven known compounds (1-3,5-8) and a new one (4) were isolated from the petroleum ether and ethyl acetate extracts by repeated silica gel column chromatography. Their chemical structures were identified as: lanosta-8,24-dien-3 β -ol (lanosterol) (1), lanosta-8,24-diene-3 β ,22R-diol (inotodiol) (2 and 3),ergosterol peroxide (5), lanosta-8,24-diene-3 P ,21-diol (uvariol) (6), 3 P -hydroxy-lanosta-8,24-dien-21-oic acid (trametenolic acid) (7) , 3 3 ,22,25-trihydroxy-lanosta-8-ene (8) by comparison of their 'H-NMR and I3C-NMR spectra and MS data with reported values. (3) The chemical structure of compound 4 was established as lanosta-24-ene-3 P ,21-diol on the basis of spectroscopic methods such as ' H-NMR, 13C-NMR and MS, as well as DEPT-45.DEPT-90 and DEPT-135. (4) The Ames test of compound 1, 3 and 7 showed compound 1 and 3 had significant antimutagenic activity.