Isolation and identification of C-19 fatty acids with anti-tumor activity from the spores of Ganoderma lucidum (reishi mushroom)

We previously showed that ethanolic extracts of spores of Ganoderma lucidum inhibit tumor cell proliferation and induce apoptosis of HL-60 cells. The active constituents appeared to be long-chain fatty acids, particularly carbon-19 (C-19) fatty acids which have not been reported in spores of Ganoderma lucidum. In the present study, two of these C-19 fatty acids which are key compounds in the activities, were identified as their 2-naphthyl ester derivatives after esterification of a mixture of fatty acids obtained from the spores. The active compounds were determines as nonadecanoic acid and cis-9-nonadecenoic acid. The location of the double bond of cis-9-nonadecenoic acid was demonstrated by GC-MS analysis, based on the fragmentation pattern of the adduct prepared from the fatty acid and dimethyl disulfide.