Essential oil composition of Citrus medica L. Cv. Diamante (Diamante citron) determined after using different extraction methods

摘要

In this paper, we report the qualitative and quantitative composition of the volatile and the oxygenated heterocyclic fraction of citron (Citrus medica L. cv. Diamante (Diamante citron)). The fruits selected for the extraction were of three types: green citron of little size, green citron of big size, and yellow citron after 1 month from the harvest. The essential oils were extracted using three different methods. The nine samples of oil thus obtained were analyzed by high resolution GC (HRGC)-flame ionization detection (FID), HRGC-MS, and RP-HPLC. They differ only in the quantitative composition, while the qualitative profile was the same. The volatile fraction of every sample of oil is characterized by a high content of limonene, gamma-terpinene, and monoterpene aldehydes and a lower content of alpha- and beta-pinene and myrcene, sesquiterpenes, and aliphatic aldehydes. Enantioselective (Es)-GC analysis of the extracts allowed the determination of the enantiomeric distribution of five terpenoid compounds; a prevalence of four dextrorotatory isomers was observed. Oxypeucedanin was the main component of the oxygenated heterocyclic fraction in the extracts of green fruits, while citropten was the major oxygenated compound in the oil obtained from yellow citron.