Sterols of Acanthamoeba culbertsoni strain A-1

Two new sterols, stigmasta-5,7,22,25-tetraene-3 beta -ol (1) and stigmasta-5,7,14,22,25-pentaene-3 beta -ol (2), have been characterized along with ergosterol and 7-dehydrostigmasterol in the nonsaponifiable fraction of the total lipids extracted from trophozoites of Acanthamoeba culbertsoni strain A-1 (virulent strain). However, these sterols were found to be absent in the nonpathogenic strain C-7 of A. culbertsoni.