Metabolites Profiling of An Anti-Urease and Free Radical Scavenging Fraction from the Acetone Leaves Extract of Microsorum Pustulatum (G. Frost) Copel (Polypodiaceae)

Background: As a follow-up to an earlier report on the anti-urease and free radical scavenging potentials of the extracts and partitioned solvent fractions from the leaves of the epiphytic fern Microsorum pustulatum, this study is reporting the metabolites’ profile of an active chromatography fraction using Gas Chromatography- Mass Spectrometry (GC-MS). Method: The bioactive acetone extract obtained after prior defatting with n-hexane was further partitioned between chloroform and water to obtain the organic phase (AOP) and the aqueous phase (APP). The more active AOP reported earlier, was further fractionated on a chromatography column packed with normal phase silica gel and eluted with a gradient (300ml each) mixture of n-hexane:chloroform: methanol (4:0:0, 3:1:0, 2:2:0, 1:3:0, 0:4:0, 0:3:1, 0:2:2, 0:1:3, 0:0:4) and the fractions pooled based on similarities from Thin layer chromatography fingerprint. Constituents in the active chromatography fraction(s) were chararcterized using Gas Chromatography- Mass Spectrometry (GC-MS) technique. Results: Three pooled chromatography fractions A1, A2 and A3 were obtained in increasing order of polarity and A1 > A2> A3 trend was observed for both urease inhibition and free radical scavenging activities. In the GC-MS analysis, three compounds (% abundance by area): (E)-2-[(Z)[(adamantan-1-yl) (phenyl)methylidene] amino)- 1,2-diaminoethene-1-thiol (18.9%), Oxime-, methoxy- phenyl (9.02%) and a polyacetylenic alcohol derivative: Eicosa-10-en-5-yn-1-ol (1.6 %) were conclusively characterised out of the thirteen detected compounds. Conclusion: Aside serving as biomarkers for phytochemical standardization, the presence of these compounds could offer a rationale for the anti-urease and free radical scavenging activities of Microsorum pustulatum leaves thus supporting some of its ethnobotanical uses, These compounds could also serve as leads for the development of drugs and ecofriendly urease inhibitors for improved crop production.