Structures of hydroxy fatty acids as the constituents of triacylglycerols in Philippine wild edible mushroom, Ganoderma lucidum

Edible Philippine mushrooms including Ganoderma lucidum have many health benefits. We have recently reported the identities and the contents of 77 molecular species of acylglycerols containing hydroxy fatty acids (HFA) in this mushroom. The structures of these HFA were proposed using the electrospray ionization mass spectrometry of the lithium adducts of acylglycerols in the HPLC fractions of the lipid extract. The proposed structures of the HFA were OH1319:110, OH1319:114, 2OH11,1218:0, 2OH11,1218:19, 2OH11,1218:29,13, 3OH11,12,1318:19 and 3OH11,12,1318:114. The locations of the hydroxyl groups and double bonds were near the middle of the HFA chains. The structures were the same or similar to that of HFA in castor oil except that the HFA of odd numbered carbon atoms were not detected in castor oil. OH18:1 was identified in the mushroom and its structure was not OH1218:19 (ricinoleate) as that in castor oil. Ricinoleate and/or HFA (OH18:1) structurally similar to ricinoleate was likely the biological precursors of these HFA in mushroom.