Antimicrobial activity of lichen Everniastrum sp, its synergism with Sapindus mukrossi and Panax pseudoginseng: LC-MS identification of active compounds

Abstract

A fruticose lichen, Everniastrum, was screened for its antimicrobial activity against eight microorganisms in this study, and its synergistic antimicrobial activity was tested with two commonly known medicinal plants of the Darjeeling Hills. Identification of the active principle in the lichen extract and the probable active compounds was performed by LC-MS analysis. The list of names, classes, mass spectrum, and occurrence of lichen substances obtained from LC-MS Chromatogram of the methanolic extract of Everniastrum sp. revealed the presence of mainly orcinol, depsidones, and depside compounds with some aliphatic acids, xanthones, and usnic acid derivatives. The compounds present were namely hypostitic acid, salazinic acid, norstictic acid, alectoronic acid, thiomelin, conloxodin, usnic acid, and 2’-O-methylnobarbatic acid. The findings of this research indicate that the presence of distinct groups of phytochemicals in Everniastrum sp. may be explored for the development of widely acceptable agents to combat disorders without side effects.