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 1H 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 A549 and 95D cells, and human hepatocellular carcinoma HepG2 cells were measured by Cell Counting Kit-8. Results: A novel ergosterol derivative, (22 E,24 R)-3β,5β,6α,7α,14β-pentahydroxyergosta-8,22-dien-15-one (1), and 5 known sterols, (22 E,24 R)-3β,5α,9α,14β-tetrahydroxyergosta-7,22-dien-6-one (2), (22 E,24 R)-ergosta-7,9(11),22-triene-3β,5α,6β-triol (3), (22 E,24 R)-ergosta-7,9(11),22-triene-3β,5α,6β,14α-tetrol (4), β-daucosterine (5), and (22 E,24 R)-ergosta-7,22-diene-3β,5α,6β,9α-tetrol (6), were obtained from the ruptured spores of G sinense. Compound 1 exhibited cytotoxicity against A549 cells and HepG-2 cells with IC50 values of 65.12 ± 4.76 and 97.34 ± 6.36 μM, 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 A549 cells and HepG-2 cells.