Chemical Composition of Some Citrus Oils from Malaysia

The chemical composition of the peel and leaf oils of four Malaysian Citrus species (C. hystrix D.C., C. aurantifolia Swingle, C. maxima Merr. and C. microcarpa Bunge) was examined by co-chromatography, two columns of different polarity, GC/MS and linear retention indices. β-Pinene and limonene were the major constituents of the peel oils of C. hystrix (39.3% and 14.2%) and C. aurantifolia (28.4% and 39.3%). The peel oils of C. maxima and C. microcarpa were found to be rich in limonene (>94%). Citronellal at 72.4% was the most abundant compound in the leaf oil of C. hystrix. The major components of the leaf oil of C. aurantifolia were geranial (19.4%), limonene (16.4%) and neral (11.4%). Sesquiterpenes were present at 70.8% in the leaf oil of C. microcarpa where hedycaryol (19.0%), β-sesquiphellandrene (18.3%) and α-eudesmol (14.4%) were the major constituents. The leaf oil of C. maxima contained significant amounts of phytol (23.1%) and β-caryophyllene (15.4%).