Fast and effective identification of the bioactive compounds from thuja and cypress via bioactivity guided isolation approach

Abstract

In present study, Thuja orientalis (Thuja) and Cupressus sempervirens (Cypress) were collected from different agro-climatic regions of Punjab, Pakistan. These regions include Rice/ Wheat Punjab zone (Lahore, with semi-arid climate), Mixed-crop Punjab zone (Faisalabad, with desert climate) and Rain fed (Barani) Punjab zone (Islamabad, with warm and temperate climate). The leaves of Thuja and Cypress collected from each region were subjected to hydrodistillation and steam distillation separately, to extract essential oils from them. The yields of essential oils were found to be affected significantly by distillation methods as well as regional variations. The initial TLC analysis of these essential oils showed that these samples were consisted of different polarity groups, ranging from highly polar oxygenated compounds to semi-polar or non-polar terpene hydrocarbons. The chemical composition of all of these essential oils was studied by GC/MS which showed the presence of different major components in different essential oils, depending on regional variations and distillation methods. These essential oils were fractionated into different fractions by vacuum distillation fractionation and high speed counter current chromatography (HPCCC). The results of different biological activities showed that all of these essential oils and fraction were having significant antioxidant, antibacterial and antibiofilm potential. Also, the fractions were mostly found to be more active than pure essential oils. The results of GC/MS analysis of most active fractions showed that vacuum fractions were mainly consisted of groups of compounds with two or more compounds in higher percentage while HPCCC fractions were consisted of relatively pure compounds with higher concentration. The bioactive compounds which were isolated from different fractions of Thuja and Cypress essential oils were α- Pinene, α- Cedrol, Δ-3-Carene, - Pinene, α-Terpinyl acetate, α- Humulene, cis-Limonene oxide, and Isoaromadendrene epoxide.