Zingiber vuquangensis and Z. castaneum: Two newly discovered species from Vietnam and their essential oil constituents

Abstract

The chemical constituents of essential oils obtained by hydrodistillation from Zingiber vuquangensis Lý N.S., Le T.H., Trinh T. H., Nguyen V.H., Do N.D. and Zingiber castaneum Škornick. & Q.B. Nguyen collected from Vu Quang National Park, Hà Tinh Province, Vietnam were analysed by GC and GC-MS. β-Pinene (24.7% and 26.1%) and β-caryophyllene (12.3% and 13.9%) were the main constituents in the leaf oil and stem oil of Zingiber vuquangensis. On the other hand the root oil contained bornyl acetate (20.9%), zerumbone (14.1%) and α-humulene (9.6%) while β-pinene (19.6%), 1,8-cineole (15.6%), α-pinene (10.3%) and β-caryophyllene (10.4%) were the significant compounds of the fruit oil. The leaf oil Zingiber castaneum was dominated by β-pinene (30.6%), α- pinene (9.5%), β-caryophyllene (9.4%) and bicycloelemene (9.1%). The compounds occurring in higher quantity in the stem oil were β-caryophyllene (14.7%), δ-cadinene (9.8%), bicycloelemene (8.4%) and α-cubebene (7.8%). However, camphene (15.1%), 1,8-cineole (13.6%), linalool (11.3%) and δ-3-carene (8.5%) were the main compounds of the root oil while (E)-nerolidol (23.2%), (Z)-9-octadecenamide (17.3%) and β-caryophyllene (10.8%) were the main constituents of the fruit oil. The essential oil did not exhibit noticeable antimicrobial effects. This is the first report on the volatile compositions of Z. vuquangensis and Z. castaneum.