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SYNTHESIS AND BIOLOGICAL STUDIES ON SOME HETEROATOM CONTAINING MOLECULES AND PHYTOCHEMICAL INVESTIGATION ON SALSOLA FOETIDA

Maharvi, Ghulam Murtaza (2004) SYNTHESIS AND BIOLOGICAL STUDIES ON SOME HETEROATOM CONTAINING MOLECULES AND PHYTOCHEMICAL INVESTIGATION ON SALSOLA FOETIDA. PhD thesis, University of Karachi, Karachi.

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Abstract

This dissertation comprises of two parts. The part-A describes the synthesis and biological studies on some heteroatom containing molecules through improved methodologies in organic synthesis. The part-B describes the isolation and structural characterization of secondary metabolites from, Salsola foetida Linn Part-A This part describes the synthesis and biological studies on some heteroatom containing molecules. The work embodied in this part has been divided into chapters. Chapter-A: The work reported in this chapter deals with a modified, economical and efficient synthesis of various pyrazolo[4,3-d]pyrimidin-7-ones; sildenafil (Viagra®) and its analogues possessing enzyme inhibitory activities. Additionally, a series of new methyl ether derivatives of sildenafil (Viagra®) possessing very interesting tyrosinase inhibitory potential were also synthesized. A brief structure-activity relationship (SAR) is discussed in this chapter Chapter-2: This chapter describes the synthesis of a variety of tetraketones with variable substituents at C-7 and were evaluated as tyrosinase inhibitors. This series of tetraketones molecules are found to be good inhibitors for the tyrosinase enzyme. Remarkably, compounds 50 (IC50=2.06μM), 36 (IC50=2.09μM), 41 (IC50=2.61μM), and 52 (IC50=3.19μM), were found to be the most active compounds of the series, which are even more potent than the standard drugs, kojic acid (IC50=16.67μM), and L-mimosine (IC50=3.68μM). This study may lead to the discovery of some lead compounds for the management of a number of dermatological disorders including hyper-pigmentation, as well as for the treatment of skin melanoma Chapter-3: In this chapter a new method for the esterification of aromatic carboxylic acids by substituted toluenes in a mixture of sodium bromate and sodium hydrogen sulfite in a two-phase system is described Phytochemical investigations on the air-dried whole plant Salsola foetida resulted in the isolation and structural determination of three new compounds, 3-(4””-dimethoxyphenyl)-N-[2’-(3”,4”-dihydroxyphenyl)-2’-hydroxyethyl]acrylamide (37), 3-(3””,4””-dimethoxy-phenyl)-N-[2’-(3”-4”-dihydroxyphenyl)-2’-hydroxyethl]acrylamide 39). Eight known compounds namely Stigmasterol (43), β-Sitosterol (44), Isoscopoletin (45), Scopoletin (46), Daphnoretin (47), 3-({6-[(β-D-glucopyranosyl)oxy]-2-oxo-2H-1-benzopyran-7-yl}oxy)-7-methoxy-2H-1-benzopyran-2-one (48), Bergaptol (49), Bergaptol-O-β-D-glucopyranoside (50) were also isolated for the first time from Salsola foetida. The structure elucidations of these compounds were carried out with the help of modern spectroscopic techniques. Compounds 37-39 exhibited potent tyrosinase inhibitory and antioxidant activities. Helv. Chim. Acta 2003, 86, 457. Helv. Chim. Acta 2003, 86, 457. Helv. Chim. Acta 2003, 86, 457

Item Type:Thesis (PhD)
Uncontrolled Keywords:heteroatom, salsola foetida, tetraketones, tyrosinase, toluenes, aromatic carboxylic acids, sildenafil citrate, cinnamic acids, noradrenaline, chenopodiaceae, salsola linn
Subjects:Physical Sciences (f) > Chemistry(f2)
ID Code:1332
Deposited By:Mr. Muhammad Asif
Deposited On:27 Jan 2007
Last Modified:04 Oct 2007 21:05

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