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CHEMICAL AND BIOLOGICAL STUDIES ON SOME MEMBERS OF ASTERACEAE FAMILY AND PSEUDOCALYMMA ELEGANS, A NATIVE OF BRAZIL

Muhammad, Jahangir (2001) CHEMICAL AND BIOLOGICAL STUDIES ON SOME MEMBERS OF ASTERACEAE FAMILY AND PSEUDOCALYMMA ELEGANS, A NATIVE OF BRAZIL. PhD thesis, University of Karachi, Karachi.

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Abstract

The work embodied in this dissertation in mainly concerned with the isolation and characterization of chemical constituents from terrestrial plant. The isolated compounds were either new or previously been reported in the literature. They were characterization by various sophisticated spectroscopic techniques available at this institution. The first chapter is a general article describing about medicinally important plants and drugs from them as a gift of nature to us. The same chapter describes various steps involved in drug discovery. The second chapter entitled “Pulicaria gnaphalodes” shows the chemical analysis of the titled pant belonging to the family asteracease. As a results of this analysis, a new dimmer of sequiterpene (gnapholide) was isolated and characterized, along with another known dimmer of the same skeleton, a sesquiterpenoid, four flavonoids and a benzoic acid derivative reported for the first time form this source. The third chapter entitled “Tridax Procumbens” covers the phytochemical investigations as well as syntheses of oleanolic acid derivatives, which was obtained form the titled source of the same family in good amount for biological studies. During the phytochemical analysis a new dimmer of bithiophene (tridbisbithiophene) was obtained along with four commonly known triterpenoids reported first time form this source. The next chapter (fourth) entitled “Artemisia scoparia” shows the isolation purification and characterization of tow new benzene derivatives (scopariendiol and scoparal) a new isocoumarin (Scoparin) along with pair of isomeric coumarins (sabandin-A and B) which were ambiguously characterized previously by Reyes in 1970, together with a flavone, tow steroids and their glucosides for the first time form the is source. The fifth and second last chapter of the dissertation is based on a plant named pseudocalymma elegens, a native of Brazil, belonging to the family bignoniaceae which was selected for phytochemical screening due to its significant toxicological features. As a re results of phytochemical screening, two new iriboiae glucosides(eleganoside- B and C) along with two flavone of glycosides were obtained for the fist time from this source. The final chapter (sixth) covers the results obtained from four bioassays of various crude extracts, semi-pure fraction, pure compounds of above mentioned sources and enzyme inhibition study by oleanolic acid and its synthetic derivatives. The various purified samples could not be tested biologically due to, either lack of their amounts or solubility. In the end of the thesis, a list of publications made by author and published papers (to date) related to the work described in the dissertation are bound. It is to clarify here that each chapter has corresponding references, descriptions of investigated plant, survey. During the phytochemical search, altogether nine new several known constituents were obtained. As a results of this research, up till now two paper have been published, tow are submitted for publication and the remaining two are in under preparation

Item Type:Thesis (PhD)
Uncontrolled Keywords:asteraceae family, pseudocalymma elegans, terrestrial plant, bignoniaceous plant, asteraceous plants, pulicaria gnaphalodes (vent.) boiss, tridax procumbens l., artemisia scoparia waldst, pseudocalymma elegans(vell.) kuhlm
Subjects:Physical Sciences (f) > Chemistry(f2)
ID Code:1062
Deposited By:Mr. Muhammad Asif
Deposited On:20 Jan 2007
Last Modified:04 Oct 2007 21:04

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