Subcritical Fluid Extraction of Macro Lichens, Optimization and Phytochemical Screening

In the present study, we made an effort to screen the novel bioactive compounds from macro lichens using subcritical fluid extraction method. The lichens of genus namely Flavoparmelia caperata, Pamtrema pseudotinctorum, Ramalina hossei, P. grayanum, Heterodermia comosa, Physcia aipolia and Roccella montagneig collected from Western Ghats regions of Shivamogga district, Karnataka were used in our study. Based on the availability and abundance of lichen material, two macro lichens viz. , P. pseudotinctorum and R. hossei were selected for Sub-critical Fluid Extraction (SCFE). In optimization of SCFE process was noticed that, at 60 bar to 70 bar pressure the gradual increase of extract from 2.60 % to 3.18 % in P. pseudotinctorum and 2.83 %to 3.39 % R. hossei respectively. In-case of time of interaction gradual increase in the weight of extract from 2.31 g to 3.13 % and 2.63 % to 3.29 % in case of P. pseudotinctorum and R. hossei respectively at 60 minutes. The temperature shows positive influence on the yield, gradual increase in temperature range from 30 to 40 C the amount extract was increased from 2.22 to 5.94 % and 2.45 to 6.22 % for the P. pseudotinctorum and R. hossei respectively. Preliminary phytochemical analysis of sub-critical fluid extracts of lichens revealed the presence of tannins and absence of flavonoids and saponins. Steroids were detected in P. pseudotinctorum while terpenoids, alkaloids, glycosides were detected in R. hossei. Among lichens, high carbohydrate content (59.9 %) was observed in R. hossei than P. pseudotinctorum (53.2 %). Nutritive value (cal/100 g) was found to be greater than 300 cal/100 g in both the lichens. It was found to be higher in case of R. hossei than P. pseudotinctorum. Phosphorus was found to be higher in case of P. pseudotinctorum while potassium content was same in both the lichens. In case of microelements, P. pseudotinctorum was rich in Fe, Mn, and Zn. R. hossei was found to possess high concentration of Cu.