Essential oils of Lauraceae: antimicrobial activity and constituents of Cinnamomum auricolor Kosterm. and Cinnamomum petelotii Kosterm leaves essential oils from Vietnam

In this study, the antimicrobial activity and constituents of essential oils from the leaves of Cinnamomum auricolor Kosterm. and C. petelotii Kosterm collected from PU Ho?t Natural Reserve (H?nh D?ch Commune, Qu? Phong District), Vietnam were reported. The essential oils obtained by separate hydrodistillation were analyzed by means of gas chromatography (GC) and gas chromatography coupled with mass spectrometry (GC-MS). The antimicrobial activities were evaluated by microbroth dilution susceptibility assay. The main constituents of C. auricolor comprised of oxygenated sesquiterpenes mainly caryophyllene oxide (26.0%), spathulenol (11.1%), and (E)-nerolidol (10.7%). However, oxygen-containing monoterpenes were the main compounds identified in S. petelotii and they are linalool (34.3%), 1,8-cineole (20.8%) and terpinene-4-ol (9.9%). The essential oil of C. auricolor displayed prominent antimicrobial activity towards Bacillus cereus ATCC14579 and Staphylococcus aureus ATCC25923 with minimum inhibitory concentration (MIC) value of 16.0 mu g/mL. In addition, the essential oil of C. auricolor also exhibited antimicrobial activity against Enterococcus faecalis ATCC29212, and anti-candidal activity towards Candida albicans ATCC10231 with MIC value of 32.0 mu g/mL. The leaf essential oil of C. petelotii only exhibited activity towards S. aureus and C. albicans with MIC value of 64.0 mu g/mL. The chemical constituents and antimicrobial activity of both essential oils are being reported for the first time.