Chemical Composition of Volatile Oils of Fresh and Air-Dried Buds of Cannabis chemovars, Their Insecticidal and Repellent Activities

Abstract

The volatile oils of fresh and air-dried buds of 3 different varieties of Cannabis, namely, high cannabidiol (CBD) chemotype, intermediate CBD/tetrahydrocannabinol (THC) chemotype, and high THC chemotype were prepared by hydrodistillation. Gas chromatography analysis of the volatile oils resulted in the identification of 71 compounds, of which 33 were monoterpenes and 38 were sesquiterpenes. The volatile oil obtained from the THC chemotype showed an increase in the ratio of the sesquiterpenes to monoterpenes content. The content of terpinolene was dramatically decreased upon drying of THC chemotype. Moderate increase in β-caryophyllene and caryophyllene oxide was observed. However, there was no detectable change in the percentage of monoterpenes and sesquiterpenes content in both the intermediate type and CBD chemotype upon drying. The insecticidal activity of the volatile oils was evaluated. The oil obtained from the fresh and dried high CBD cannabis showed good biting deterrent activity at 10 ug/cm2 compared with N,N-diethyl-meta-toluamide at 4.78 µg/cm2, and good larvicidal activity.