Chemical Composition of Essential Oils from Four Vietnamese Species of Piper (Piperaceae)

The chemical composition of essential oils from four Piper species, Piper retrofractum Vahl., P boehmeriaefolium (Miq.) C. DC., P sarmentosum Roxb., and P maclurei Merr., were analysed by gas chromatography-flame ionization detector (GC-FID) and gas chromatography-mass spectrometry (GCMS). Nineteen to sixty-four compounds representing 92.0%-98.4% of the total contents were identified in the oil samples. The major constituents identified in P retrofractum leaf oil were benzyl benzoate (14.4%), myrcene (14.4%), bicycloelemene (9.9%), bicyclogermacrene (7.0%) and beta-caryophyllene (5.3%). On the other hand, the main constituents of P boehmeriaefolium were alpha-copaene (28.3%), alpha-pinene (7.4%) and 1, 8-cineole (5.7%). P sarinentosum showed a very different chemical profile characterized mainly by aromatic compounds and devoid of monoterpene hydrocarbons. The major constituents were benzyl benzoate (49.1%), benzyl alcohol (17.9%), 2-hydroxy-benzoic acid phenylmethyl ester (10.0%) and 2-butenyl-benzene (7.9%). The leaf of P maclurei was characterized by higher amount of (E)-cinnamic acid (37.4%) and (E)nerolidol (19.4%). Moreover, (Z)-9-octadecanoic acid methyl ester (28.0%), (E)-cinnamyl acetate (17.2%), phytol (12.2%) and (E)-cinnamaldehyde (8.8%) were the major compounds identified in the stem oil.