Antimicrobial, Antioxidant Activities and Compounds Identification of Parmotrema rampoddense (Nyl.) Hale

Crude extracts in five different polarity solvents of a foliage lichen Parmotrema ramppodense collected from the Indian Himalayan region, were tested against Gram-negative bacteria and fungi at a concentration of 20 μL/disc. The Minimum Inhibitory Concentration (MIC) was tested at concentrations ranging from 10 to 0.001 mg/mL. The methanol extract yielded the highest Zone of inhibition (ZOI) against P. syringae 13.8 ± 01 mm and MIC values of 0.8 mg/mL than the acetone extract with a ZOI of 9.6 ± 0.8 mm. Principal Component Analysis has been used to summarize the most active antimicrobial extracts of lichens. The maximum (72.45 ± 0.4%) free radical scavenging activity has been observed at 1.00 mg/mL concentration and significant ferrous reducing activities (0.09) was observed at 1.00 mg/mL concentration. Both extracts of methanol and acetone exhibiting higher activity were further subjected to GC-MS chromatography and identified some compounds, viz. Threitol, Octadecanoic acid, 4-Mercaptobenzoic acid, DL-Glyceraldehyde, α‑D-Glucopyranoside and Phenylacetic acid that probably responsible for biological activities.