Essential oils of two Zingiber plants Zingiber eberhardtii Gagnep. and Zingiber skornickovae N.S. Lý: Chemical profiles and antimicrobial effects

Abstract Zingiber is a genus of medicinal plants containing a rich resource of essential oils. The current study aims to describe chemical analysis and antimicrobial assay for two Zingiber species Zingiber eberhardtii Gagnep. and Z. skornickovae N.S. Lý. The rhizome oils, which were obtained by hydro-distillation using a Clevenger apparatus, were analyzed by GC-MS (gas chromatography-mass spectrometry). Extraction of Z. eberhardtii rhizome gave a yellow oil with 41 identified compounds (96.3%), in which linalool (34.9%) and 1,8-cineole (12.7%) were the principal compounds. The yellow oil of Z. skornickovae rhizome included 53 identified compounds (97.8%), with β-pinene (25.0%), (E)-caryophyllene (8.8%), and α-pinene (7.9%) as the major agents. By broth dilution method, both oils moderately controlled the growth of Gram (+) bacteria Bacillus subtilis ATCC 6633 and Staphylococcus aureus ATCC 25923 with the same MIC (minimum inhibitory concentration) value of 128 μg/mL. In particular, Z. skornickovae rhizome oil showed the best antimicrobial activity against yeast Saccharomyces cerevisiae ATCC 4098 with a MIC value of 64 μg/mL. The obtained results are promising information for future research.