Seasonal and Developmental Dynamics of the Essential Oil Content versus Catalytic Activity of Alcohol Acyltransferase in Foliage of Citronella

Abstract

Citronella (Cymbopogon winterianus Jowitt) is an aroma grass cultivated as a cash crop for its foliage essential oil that is widely used in cosmetics/perfumery, insect-repellents, as source of synthagens etc. The oil comprises of mainly acyclic monoterpenols (geraniol and citronellol) and their esters (geranyl acetate and citronellyl acetate), besides citronellal. This study was undertaken to profile dynamics of the oil content and composition as a function of ontogeny and annual pattern of seasons and climate, including with reference to the volatile esters and catalytic activity of the enzyme involved in their synthesis, a BAHD-alcohol acetyltransferase, citronellol; acetyl coenzyme A, acetyltransferase. This may be the first report on arriving at average patterns from a three years reiterated study and on any enzymatic study of secondary metabolism of the grass. The oil ester content appeared to be governed by limitation of the acetyltransferase activity rather than availability of substrates (citronellol and geraniol).