Exploring natural essential oil components and antibacterial activity of solvent extracts from twelve Perilla frutescens L. Genotypes

Pharmaceutical active ingredients from medicinal plants can be seen as a gateway to drug discovery with the importance of medical and health care. Perilla frutescens has been traditionally used for medicinal and flavoring purposes, thus aromatic compounds and antimicrobial activity of twelve accessions of three solvent extracts (distilled water, methanol and ethyl acetate) of P. frutescens L. Britt grown under open field was studied. RauTiaTo showed relatively high essential oil (EO) content and EO yield, followed by 203P and J1 genotypes. Twenty four monoterpene hydrocarbons, eighteen sesquiterpenes, eight oxygenated compounds alcohols, five aldehydes, three phenols, other relatively low contents such as four esters and one phenylpropanoid were found. The chief natural constituents of the EO extracted from perilla genotypes were perillaldehyde in (RauTiaTo, J1, 203P, PS1, JTD3, NP606 and 588P), 13-dehydro-elsholtzia ketone in GB, MP3, and PS3 respectively, followed by perilla ketone in PS2 and 465P. Other natural compounds were limonene, 13 caryophyllene, (Z,E)-alpha-Farnesene, shisofuran and trans-shisool. Aqueous extract of PS2, 588P and JTD3, as well as antibiotic gentamicin, inhibited more strongly the growth of Klebsiella spp., than other solvent extracts using disc diffusion method. Gentamicin showed a very strong antibacterial activity against Staphylococcus aureus., Streptococcus pneumonia., Klebsiella spp., Shigella spp., Salmonella spp., Escherichia coli with varying degree of inhibition, while another amoxicillin was only active against bacterial infections Streptococcus pneumonia and Escherichia coli. The combination 2 and 3 of herbal preparation showed the antibacterial activity against Streptococcus pneumonia respectively. These results can be helpful for qualitative and quantitative analyses of this herbal drug and food additives in quality control for the standardisation of natural products. (C) 2020 Published by Elsevier B.V. on behalf of King Saud University.