Chemical investigation and biological activities of Patchouli (Pogostemon cablin (Blanco) Benth) essential oil

Pogostemon cablin (Blanco) Benth. plant is known to synthesize the precious and most valuable essential oil available today on perfumers pellet. Because of its limited production in South East Asian countries like Indonesia, the high demand is always a challenge for the producing countries. In order to meet the market demand, CSIR-CIMAP has developed a high essential oil yielding patchouli var. CIM-Utkrisht for cultivation in India. Since the variety possessed a unique fingerprint of essential oil, furthermore, due to patchouli’s more acceptance as ingredients of many perfume preparations, the volatile oils are rarely investigated for biological action, anti-inflammatory, in particular. We investigated the essential oils obtained from dried aerial parts of the plant for their antimicrobial and anti-inflammatory potential. The anti-inflammatory activity (TNF-α) was significantly reduced (p < 0.05) in patchouli essential oil treated cells as compared to vehicle control. Essential oil exhibited In-vitro antimicrobial activity against five selected microorganisms’ viz., C. albicans, S. typhimurium, S. aureus, E. coli, and M. furfur. In particular, essential oil obtained from 14 days of drying showed the most potent action (zone inhibition, 16.0 ± 3.0) against M. furfur. The GC-FID, GC/-MS and NMR investigations revealed presence of an array of sesquiterpenoids such as curcumenes (γ-curcumene; 22.0–25.0% & ar-curcumene; 1.3–3.1%), 7-epi-cis-sesquisabinene hydrate (0.3–0.5%), and some guaiane-type sesquiterpenoids like guaia-1(5)-11-dien-3-ol (1.5–4.6%), guaia-11-en-5-ol (0.1–0.2%), guaia-4(5)-11-dien-6-ol (0.6–0.9%), guaia-1(10)-11-dien-9-one (0.4–1.2%) and guaia-1(10)-11-dien-9-one-8-ol (1.4–1.6%). The current work is the first report of bisabolane-type sesquiterpenoids from the genus Pogostemon with high γ-curcumene (22.0–25.0%). Being a highly esteemed basic ingredient of modern perfumery, the patchouli oil is frequently adulterated with non-volatiles compositions to comply with the market demands. We report herein simultaneous thermo-gravimetric analysis-based detection method for authentication of patchouli essential oils for the first time.