Abstract

The aim of this study is to identify and characterize the bioactive principles from the roots ofWrightia tomentosa. For isolation, the compound, the dried root powder of W. tomentosawas subjected to hot extraction with n-hexane to chromatography. Two compounds (WTRHF₄ and WTRHF₇) were isolated and purified by chloroform: toluene (7.5: 2.5) and chloroform: ethyl acetate (6: 4), respectively. The infra-red (I.R) spectra of WTRHF₄showed specific absorption bands for proteins, viz., 3689 to 3629 cm^-1 for COOH stretching; 2375 cm^-1 for NH₃⁺ stretching; 1726 cm^-1 for COO^- stretching; and the Mass spectrum of WTRHF₄ showed the parent molecular ion (M )⁺ cum base peak at m/z 663.5. In addition, the I.R spectra of WTRHF₇ showed specific absorption bands for flavonoids,viz., 3780 cm^-1 for stretching alcohol and phenol; 1098 to 1048 cm^-1 for C-O-C stretching; 1445 to 1375 cm^-1 for O-H δ ip phenol; 1739 cm^-1 for C=O stretching and the mass spectra of WTRHF₇ showed a parent molecular ion (M+1)⁺ peak at m/z 423.4 which corresponds to the molecular formula C₁₉H₁₈O₁₁. From the physical, chemical and spectral characteristics, WTRHF₄ and WTRHF₇ were concluded as amyloid β-protein (Aβ_17-28) and mangiferin, respectively.

Key words: Wrightia tomentosa, n-hexane, roots, mangiferin, amyloid β-protein.