Analysis of Prenyllipids in the Chloroplasts of the Liverwort Heteroscyphus Planus

Liverworts belonging to the Class Hepaticae of the Division Bryophyta, are an excellent source of lower terpenoids. They possess intracellular oil bodies which are composed of lipophilic terpenoids and aromatic compounds. In this study, an attempt was made to identify the prenyllipid component that is localized to the chloroplasts of the liverwort, Heteroscyphus planus (Mitt.) Shiffner. The prenyl diphosphates were extracted by stirring the intact chloroplasts overnight in methanol, without rupturing the chloroplasts in liquid nitrogen. The chloroplasts were found to contain farnesyl diphosphate and geranylgranyl diphosphate which were detected after hydrolysis by alkaline phosphatase to their respective isoprenols, farnesol and geranylgeraniol. Hydrolysis with KOH yielded phytol and geranylgeraniol which were present in the chloroplasts as esters with chlorophyllide (chlorophyll a and geranylgranyl diphosphate-chlorophyllide respectively). Only phytol was detected at high level, whereas, geranylgranyl diphosphate and geranylgranyl diphosphate-ester were at very low levels. The cis and trans isomers of farnesol were separately identified, but in very low quantities. These results were further confirmed by GC-MS analysis. Linoleic acid, palmitic acid, methyl ester of palmitic acid and the ester of phthalate acid were identified as other lipids localized to the chloroplasts of H. planus.