PHYTOCHEMICAL AND BIOLOGICAL STUDY ONMARKHAMIA LUTEA (MARKHAMIA PLATYCALYX) FAMILY BIGNONIACEAE

Abstract

In accordance with the recent world-wide interest in plant phenolics which emerges from their broad range of biological activities, particular emphasis has been focused, in the present thesis, on the constitutive phenolics and triterpenic acids of the extract of Markhamia lutea (Family bignoniaceae). The present study is divided into three parts in two chapters Part I: Phytochemical investigation of the aqueous methanolic leaf extract of Markhamia lutea Family Bignoniaceae. Part II: Phytochemical investigation of the hexane extract of Markhamia lutea including the isolation of different triterpenic acids. Part III: Biological investigation of the antidiabetic activity of the hydroalcoholic leaf extract of Markhamia lutea Family Bignoniaceae. 1. Part I: Phytochemical investigation of the aqueous methanolic leaf extract of Markhamia lutea Family Bignoniaceae This includes HR-ESI-MS profiling of the total extract and its fractions beside the isolation of verbascoside (the major compound) which exist in the extract and may be responsible for its antidiabetic activity.

1.1. HR-MS analysis: This analysis was performed to the total hydroalcoholic extract of M.lutea and its main fractions so as to profile and track the major constituents that may be responsible for the hypoglycemic effect of the extract. The mass analysis resulted in the tentative identification of 29 compounds from different phytochemical classes mainly phenyl propanoids and flavonoids with verbascoside (m/z 623) being the major compound in the earlier fractions (1,2 and 3) however luteolin-7-O-glucuronide (m/z 923 being in dimer form) being the major constituent in the latter fraction (4).

1.2. Verbascoside isolation from fraction 2: As verbascoside (m/z 623) is the major compound in M. lutea fractions (1, 2 and 3) so it was isolated according to the scheme illustrated below (Fig 72).

1.3. Standardization of the hydromethanolic extract of Markhamia lutea using verbascoside standard.

2. Part II: Phytochemical investigation of the hexane extract of Markhamia lutea

This includes the isolation and identification of three triterpenic acids (musambin A, B & C) and their xyloside derivatives beside 2-epitormentic acid.The compounds show a reported antiparasitic activity (musambins) however 2-epitormentic acid showed reported anti-inflammatory & anti-tumor activity.