Effect of Sample Preparation on the Amounts of α-Pinene and Verbenone Extracted from Rosemary

Abstract Volatile compounds were obtained from fresh leaves of rosemary by accelerated solvent extraction (ASE), super-critical fluid extraction (SFE) and steam distillation. It was found that the ratio of α-pinene to verbenone depended on the method of preparation of plant material, and that the yield of verbenone was largest from ground leaves, while the amount of α-pinene was greatest in whole leaves. The transformation of α-pinene to verbenone is thought to be the cause for the differences in the relative amounts of these two major components.