In vitro antifungal activity and phytochemical analysis of lichen Parmelia perlata (L.) Ach.

Abstract

Fungal diseases like candidiasis and cryptococcosis are the commonest opportunistic infections. Since the difficulties associated with the management of antifungal infections, there is an urgent need for the development of new and effective antifungal agents. In this perspective, natural products are a viable alternative source. The lichen Parmelia perlata, commonly known as stone flower, is traditionally used in the Indian system of medicine. The aim of the present study was to evaluate in vitro antifungal activity of petroleum ether extract of Parmelia perlata against Candida albicans, Candida glabrata, Candida krusei, Candida tropicalis, and Cryptococcus neoformans and its phytochemical analysis. The anti-fungal activity of the extract of Parmelia perlata was determined by measuring the Minimal Inhibitory Concentration (MIC) and Minimum Fungicidal Concentration (MFC) by microbroth dilution method as per the CLSI (NCCLS M27-A2) guidelines. The extract of Parmelia perlata showed the MIC and MFC against Candida species between 600±28µg/ml to 690±16µg/ml and between 750±90µg/ml to 820±45µg/ml, respectively. In addition, the respective values against Cryptococcus neoformans were 550±17µg/ml and 690±34µg/ml, respectively. Further, Parmelia perlata has yielded an acid named- (+)-6-deacetyl-9b-carbmethoxy-9b-dimethylusnic acid and, a quinine named -6-acetyl-11-carbmethoxy-1,4,7,10-tetrahydroxy-2,8-dimethyl naphthacene-5,12-quinone, which were identified on the basis of spectroscopic studies as 2-acetyl-9b-carbmethoxy-7,9-dihydroxy-8-methyl-1,3(2H,9bH)-dibenzofurandione and naphthacene-5,12-quinone derivative, along with four well known compounds-tridecyl myristate, 3-ketooleanane, arachidyl alcohol and (+) usnic acid, respectively. The results of this study showed that Parmelia perlata is a promising antifungal agent.