Composition and antimicrobial activity of the essential oil, distilled aromatic water and herbal infusion from Epilobium parviflorum Schreb.

Abstract

The essential oil of dry leaves and stems of Epilobium parviflorum Schreb. was obtained by hydrodistillation using a Clevenger apparatus, for 5h with a 0.02% (w/w) yield. The qualitative and semi-quantitative analysis of its hexane extract by GC-FID and GC–MS showed the presence of 216 components and 123 constituents accounting for almost 94% of the oil were identified. GC–MS analysis revealed that the essential oil predominantly contains palmitic acid (30.8%), linoleic acid (12.5%) and α-linolenic acid (10.8%) as its major constituents. Analysis of aromatic water remained after hydrodistillation was performed; the main constituents were a group of monoterpenoids (38.9%). The antimicrobial activity of the distilled essential oil and the remaining aromatic water was evaluated against five microorganisms (Staphylococcus aureus, Enterococcus faecalis, Escherichia coli, Pseudomonas aeruginosa and Candida albicans) using microdilution method. Results showed significant antibacterial activity against tested bacteria and yeast. The essential oil inhibited the growth of all tested bacteria and the minimum inhibitory concentration was determined to be around 10–40μgmL−1, even in the case of yeast it was 5mgmL−1. Distilled aromatic water contains much less substances but tests showed that it still has antimicrobial activity against all tested microbes (more on Gram-negative bacteria and yeast). Further, volatile profiles were also examined at other essential oils obtained by hydrodistillation of three pure herbal teas.