GC–MS ANALYSIS OF ANTIOXIDANT COMPOUNDS PRESENT IN DIFFERENT EXTRACTS OF AN ENDEMIC PLANT DILLENIA SCABRELLA (DILLENIACEAE) LEAVES AND BARKSAbstract
The study aimed to investigate and characterize the antioxidant compounds from the leaves and barks of Dillenia scabrella (Dilleniaceae) (D. scabrella), an indigenous plant in the Northeast. The air-dried leaves and barks were powdered and subjected to selective sequential extraction using solvents of increasing polarity through percolation, namely, methanol, ethyl acetate + ethanol and water to obtain three different extracts. Further, the antioxidant potential of each of the extracts was checked by DPPH (1, 1-diphenyl, 2-picryl hydrazyl) assay. It was followed by preliminary phytochemical tests and gas chromatography-mass spectrometry to identify the anti-oxidant compound. All 4 crude extracts have shown significant antioxidant activity. The methanol extract of leaves (93%) at 500 µg/ml and bark (93.48% and 93.42%) at 500 µg/ml and 400 µg/ml showed free radical scavenging activity which was greater than the standard ascorbic acid (92.5%). In the phytochemical tests, phenolics were invariably present in all 4 extracts. Qualitative determination of the different biologically active compounds from crude extracts of D. scabrella using gas chromatography-mass spectrometry revealed different types of high and low molecular weight chemical entities with varying quantities present in each of the extracts. 16 bioactive compounds were identified in which 7 were reported for different biological activities. 3 compounds namely Cyclotrisiloxane Hexamethyl, 2, 4, 6-Cycloheptatrien-1, 3, 5-Bis-Trimethylsilyl, Trisiloxane- 1, 1, 1, 5, 5, 5-Hexamethyl-3, 3-Bis Trimethylsilyl are identified as compounds responsible for the above mentioned antioxidant property. Thus, identification of different biologically active compounds in the extracts of D. scabrella leaves and bark warrants further biological and pharmacological studies.
K. Momin and S. C. Thomas *
Department of Biosciences, Tapesia Campus, Assam Don Bosco University, Sonapur, Assam, India.
21 June 2019
14 November 2019
08 February 2020
01 May 2020