A detailed chemical composition and antimicrobial activity of Hypericum richeri Vill. subsp grisebachii (Boiss.) Nyman essential oil from Serbia

The essential oil of fresh aerial parts of Hypericum richeri subsp. grisebachii obtained by hydrodistillation was analyzed by gas chromatography (GC) and gas chromatography/mass spectral GC/MS. One hundred and five constituents identified accounted for 96.1% of the total oil. The major components of the oil were: germacrene D (13.1%), dodecanal (11.9%), beta-caryophyllene (7.4%), beta-pinene (5.8%), caryophyllene oxide (4.2%) and (E)-beta-ocimene (3.3%). The volatile profile of H. richeri subsp. grisebachii was characterized by a large amount of sesquiterpenoids (56.2%), especially by hydrocarbons of this fraction (34.1%). The in vitro antimicrobial activity of essential oil was also examined against a panel of microbial strains by broth microdilution assay and it was found to have moderate effect against all tested microorganisms.