Anticonvulsant Activity Guided Isolation of Acteoside from Methanolic Root Extracts of Colebrookea oppositifolia Smith

Abstract

Present study was aimed to isolate the anticonvulsant principle/s from methanolic root extract of Colebrookea oppositifolia (MCO). The MCO was subjected for fractionation, and column chromatography using various solvents, and the fractions obtained were evaluated using Six-hertz seizure test. The potent fraction obtained was subjected for detailed spectral analysis to identify the possible chemical structure. Initially, the MCO was made into 3 three major fractions, namely n-butanol soluble fraction, ethyl acetate soluble fraction and residue fraction. The n-butanol fraction has shown better anticonvulsant activity; therefore, it was subjected for column chromatography. A total of 72 fractions (Fr-1 to Fr-72) of 100 ml each were collected and the fractions with similar TLC pattern were pooled together to form 11 pooled fractions (Fr-I (1-5), Fr-II (6-10), Fr-III (11-21), Fr-IV (22-29), Fr-V (30-36), Fr-VI (37-44), Fr-VII (45-52), Fr-VIII (53), Fr-IX (54-60), Fr-X (61-66), Fr-XI (67-72)). In six-hertz seizure test, the Fr-X (61 to 66) was identified as a most potent fraction, and upon crystallization from methanol/chloroform, yielded a light brown colored amorphous powder (COP-I - 1.6 g) soluble in water. Furthermore, the COP-I was subjected for detailed spectral analysis (UV, FT-IR, 1H-NMR, 13C-NMR and Mass), and based on the spectral analysis, it was identified as Acteoside (Verbascoside), belongs to phenylethanoid class of glycosides. Based on bioactivity guided isolation process, COP-I was isolated from MCO, and based on detailed spectral analysis the COP-I was identified as Acteoside.