Essential Oils of Piper pendulispicum C. DC. and Piper hymenophyllum Miq.: Chemical Composition and Anti-microbial activity

From hydro-distillation and GC-FID/MS (gas chromatography-flame ionization detection/mass spectrometry) analysis, chemical compositions in essential oils of two Vietnamese Piper plants Piper pendulispicum C. DC. and P. hymenophyllum Miq. were identified. Essential oils of P. pendulispicum leaf and stem are highlighted with the predominant amount of sesquiterpene hydrocarbons (73.21-78.06%), in which bicyclogermacrene (12.17-12.54%) and beta-caryophyllene (12.10-14.51%) were the principal compounds. Monoterpene hydrocarbons (87.44%) are the main chemical class of P. hymenophyllum leaf oil, in which alpha-pinene (52.92%) and beta-pinene (26.65%) are the principal compounds. These obtained essential oils with the MIC (minimum inhibitory concentration) values of 16-128 mu g/mL are better than the positive control streptomycin ((MIC 128-256 mu g/mL) in antimicrobial assay against three Gram-positive bacteria Enterococcus faecalis ATCC 29212, Staphylococcus aureus ATCC 25923, and Bacillus cereus ATCC 14579. P. pendulispicum essential oils (MIC 16-32 mu g/mL) are also comparable to the other standard cycloheximide (MIC 32 mu g/mL) against the yeast Candida albicans ATCC 10231. In general, P. pendulispicum essential oil is better than P. hymenophyllum leaf oil for antimicrobial treatment.

Automated summary

Chemical compositions of essential oils from two Vietnamese Piper plants, Piper pendulispicum C. DC. and P. hymenophyllum Miq., were identified through hydro-distillation and GC-FID/MS analysis. The essential oils of P. pendulispicum leaf and stem were mainly composed of sesquiterpene hydrocarbons, with bicyclogermacrene and beta-caryophyllene as the principal compounds. P. hymenophyllum leaf oil was mainly composed of monoterpene hydrocarbons, with alpha-pinene and beta-pinene as the principal compounds. These essential oils exhibited better antimicrobial activity than the positive control streptomycin against three Gram-positive bacteria and comparable activity to cycloheximide against Candida albicans. Overall, the essential oil of P. pendulispicum showed greater potential for antimicrobial treatment than P. hymenophyllum leaf oil.