Triterpenoids and an alkamide from Ganoderma tsugae

Ganoderma tsugae is a medicinal mushroom. In a continual study on the bioactive constituents of this fungus, a new lanostanoid, 3 beta-acetoxy-16 alpha-hydroxy-24 xi-methyl-5 alpha-lanosta-8,25-dien-21-oic acid, named tsugaric acid F (1) and a novel palmitamide, N-(3'alpha,4'beta-dihydroxy-2'beta-(hydroxymethyl)-1'beta-(cyclobutyl)palmitamide (2) were isolated and characterized from the fruit bodies of G. tsugae, and three novel seco-lanostanoids, 3,4-seco-8 alpha,9 alpha-epoxy-5 alpha-lanosta-21-oic acid 3,4 lactone (5), 3,4-seco-5 beta-lanosta-7,9(11),4(29)-trien-3,21-dioic acid-3-methyl ester (6), 3,4-seco-5 beta-lanosta-7,9(11),4(29)-trien-3,21-dioic acid (7), and a known compound, 3-oxo-5 alpha-lanosta-8-en-21-oic acid (4) were prepared from 3. The structures of new compounds, 1, 2, 5-7 were determined by spectroscopic methods. Compounds 1 and 4 showed inhibitory effects on xanthine oxidase (XO) with an IC50 values of 3133 +/- 80.0 and 43.9 +/- 29.9 mu M, respectively when 7 exhibited potent inhibitory effect on superoxide anion generation in rat neutrophils stimulated with formyl-Met-Leu-Phe (fMLP)/cytochalasin B (CB) with an IC50 values of 1.3 +/- 0.2 mu M. Compounds 4-7 showed weak cytotoxic activities against PC3 cells. These results indicated that 4 and 7 may be used as cancer chemopreventive agents. (C) 2015 Elsevier B.V. All rights reserved.