In vitro total phenolics,flavonoids contents and antioxidant activity of essential oil,various organic extracts from the leaves of tropical medicinal plant Tetrastigma from Sabah

Objective:To detect the in vitro total phenolics,flavonoids contents and antioxidant activity of essential oil,various organic extracts from the leaves of tropical medicinal plant Tetrastigma from Sabah.Methods:The dry powder leaves of Tetrastigma were extracted with different organic solvent such as hexane.ethyl acetate,chloroform,butanol and aqueous methanol.The total phenolic and total flavonoids contents of the essential oil and various organic extracts such as hexane,ethyl acetate,chloroform,butanol and aqueous ethanol were determined by Folin-Ciocalteu method and the assayed antioxidant activity was determined in vitro models such as antioxidant capacity by radical scavenging activity usingα,α-diphenyl-β-picrylhydrazyl (DPPH) method.Results:The total phenolic contents of the essential oil and different extracts as gallic acid equivalents were found to be highest in methanol extract(386.22 mg/g) followed by ethyl acetate(190.89 mg/g).chloroform(175.89 mg/g).hexane(173.44 mg/g).and Imtanol extract (131.72 mg/g) and the phenolic contents not detected in essential oil.The antioxidant capacity of the essential oil and different extracts as ascorbic acid standard was in the order of methanol extract】ethyl acetate extract】chloroform】butanol】hexane extract also the antioxidant activity was not detected in essential oil.Conclusions:The findings show that the extent of antioxidant activity of the essential oil and all extracts are in accordance with the amount of phenolics present in that extract.Leaves of Tetrastigma being rich in phenolics may provide a good source of antioxidant.

Gas chromatography-mass spectrometry analysis of various organic extracts of Merremia borneensis from Sabah

Objective:To analyse the chemical composition of different extracts of Merremia borneensis(M. borneensis) by gas chromatography-mass spectrometry(GC-MS).Methods:The dried leaves powder was extracted with methanol at room temperature by using Soxhlet extractor.Methanol crude extracts of M.borneensis were extrastel with hexane,chloroform,ethyl acetate and butanol. Results:Qualitative analyses of various organic crude extracts showed that majority of these are flavonoids,terpeniods,alkaloids and glycosides.Most of the identified compounds by GCMS are biologically important.Further the M.borneensii leaf possesses certain characteristics that can be ascribed to cultivation on a domestic plantation.Conclusions:The suitable extracts for respective compounds can be chosen on the basis of above GC-MS analysis.All the major compounds from different extracts are biologically active molecules.Thus the identification of a good number of compounds from various extracts M.borneensis might have some ecological significance.