Abstract
The structure of leucotylic acid, isolated together with leucotylin (I) and zeorin (II) from a lichen Parmelia leucotyliza NYL., has been established as 16β, 22-dihydroxy-hopan-23-oic acid (III) on the basis of chemical and physicochemical investigation. Furthermore, methyl isoleucotylate, produced in addition to methyl leucotylidienate (VI) under acidtreatment of methyl leucotylate (IV), has been elucidated as VII isomeric to IV at the C-21 geometry and hence possessing an isohopane carbon framework. The isomerizationprocedure from IV to VII has also been briefly discussed.
