Polyhydroxy Sterols Isolated From Ganoderma sinense Spores and Their Cytotoxic Activities

Background: The fruiting body of Ganoderma sinense Zhao, Xu et Zhang iscertified as an authoritative medical material in the Chinese Pharmacopoeia 2020 edition and has been used as a crude drug for a long time. G sinense spores are crucial part of the fruiting body of G sinense and exhibited antitumor and immune-enhancing activities according to our previous reports. However, there were few studies about the chemical composition of G sinense spores. This study was aimed at the structure determination and antitumor effect of the sterols isolated from G sinense spores. Methods: Modern chromatographic methods were applied to isolate compounds from the ruptured spores of G sinense. Their chemical structures were elucidated by analyses of one-dimensional and two-dimensional H-1 nuclear magnetic resonance, and high-resolution electrospray ionization mass spectrometry data. The cytotoxicities of the isolated compounds against 3 tumor cell lines, human non-small cell lung cancer Lambda 549 and 95D cells, and human hepatocellular carcinoma HepG2 cells were measured by Cell Counting Kit-8. Results: A novel ergosterol derivative, (22E,24R)-3 beta,5 beta,6 alpha,7 alpha,14 beta-pentahydroxyergosta-8,22-dien-15-one (1), and 5 known sterols, (22E,24R)-3 beta,5 alpha,9 alpha,14 beta-tetrahydroxyergosta-7,22-dien-6-one (2), (22E,24R)-ergosta-7,9(11),22-triene-3 beta,5 alpha,6 beta-triol (3), (22E,24R)-ergosta-7,9(11),22-triene-3 beta,5 alpha,6 beta,14 alpha-tetrol (4), beta-daucosterine (5), and (22E,24R)-ergosta-7,22-diene-3 beta,5 alpha,6 beta,9 alpha-tetrol (6), were obtained from the ruptured spores of G sinense. Compound 1 exhibited cytotoxicity against Lambda 549 cells and HepG-2 cells with IC50 values of 65.12 +/- 4.76 and 97.34 +/- 6.36 mu M, respectively. Compounds 1, 2, and 4 were obtained from G sinense for the first time. Conclusion: This paper is a continuation of an investigation of the chemical ingredients from G sinense spores and their antitumor effect. Only compound 1 showed weak cytotoxicities against Lambda 549 cells and HepG-2 cells.