title: Chemical composition and antimicrobial activity of three essential oils from Curcuma wenyujin.
abstract: Curcuma wenyujin is a traditional medicinal plant in China. The non-steamed rhizomes, steamed rhizomes and steamed roots of this plant are used as herbal medicines in three clinics, namely Pian-jiang-huang (PJH), Wen-e-zhu (WEZ), and Wen-yu-jin (WYJ), and are officially listed in the Chinese Pharmacopoeia. The purpose of this study was to conduct a comparative analysis of the three essential oils extracted from the C. wenyujin rhizomes and roots using GC-MS, and in doing so thirty compounds were identified. Principal component analysis (PCA) effectively distinguished the samples taken from the three different groups. Monoterpenoids, including camphene, linalool, camphor, isoborneol, borneol and eucalyptol, were characteristic components of the PJH oil, while beta-elemene, beta-elemenone, gamma-elemene and delta-elemene were typical components of the WEZ oil, and propanenitrile, caryophyllene oxide, (-)-caryophyllene, germacrene B, pogostol and alpha-humulene were representative ingredients of the WYJ oil. The ratio of sesquiterpenoids to monoterpenoids in PJH, WEZ, and WYJ were 2:1, 5:1 and 7:1, respectively. The antimicrobial activities of the three essential oils and of the six main ingredients were tested against two bacterial and one fungal strains using agar diffusion and broth dilution methods. The essential oil of PJH was shown to present a higher antimicrobial activity than that of WEZ and WYJ. Based on the Partial Least Square Model (PLS), the correlation between the antimicrobial activity of the tested oils and the identified chemical components was discussed and potential components of the antimicrobial activity were predicted according to Variable Importance in the Project (VIP) Value. The tested monoterpenes eucalyptol and isoborneol demonstrated a higher inhibitory activity than the sesquiterpenes germacrone, curdione and beta-elemene. Therefore, the potent inhibitory effect of the PJH oil might be attributed to its higher content of monoterpenes. The MIC values for the essential oils and their ingredients ranged from 62.5 to 500 microg/mL.
authors.affiliation: Institute of Chinese Materia Medica, China Academy of Chinese Medical Sciences, Beijing 100700, China.
authors.forename: Jingjing
authors.initials: J
authors.lastname: Zhu
authors.forename: Agnieszka D
authors.initials: AD
authors.lastname: Lower-Nedza
authors.forename: Meng
authors.initials: M
authors.lastname: Hong
authors.forename: Song
authors.initials: S
authors.lastname: Jie
authors.forename: Zhimin
authors.initials: Z
authors.lastname: Wang
authors.forename: Dong
authors.initials: D
authors.lastname: Yingmao
authors.forename: Christine
authors.initials: C
authors.lastname: Tschiggerl
authors.forename: Franz
authors.initials: F
authors.lastname: Bucar
authors.forename: Adelheid H
authors.initials: AH
authors.lastname: Brantner
mesh_terms: D000890:Anti-Infective Agents / Q000494:pharmacology*; D030024:Curcuma / Q000737:chemistry*; D009822:Oils, Volatile / Q000032:analysis / Q000494:pharmacology*; D025341:Principal Component Analysis
chemical_list: D000890:Anti-Infective Agents; D009822:Oils, Volatile