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ISOLATION AND STRUCTURAL STUDIES ON THE CONSTITUENTS OF CALOTROPIS PROCERA, PLUMERIA AND AMBERBOA RAMOSE

Akhtar, Nargis (1992) ISOLATION AND STRUCTURAL STUDIES ON THE CONSTITUENTS OF CALOTROPIS PROCERA, PLUMERIA AND AMBERBOA RAMOSE. PhD thesis, University of Karachi, Karachi.

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Abstract

The present doctoral thesis deals with the chemical studies on three medicinal plants of Pakistani origin. The part A describe the bioassay directed isolation on the terpenoidal and steroidal constituents of plumeria rubra which has led to the isolation and structural elucidation of two bio-active triterpenes of amyrin series, namely rubrinol(3β,30-dihydroxy-12-uresen) and 6α-hydroxy-3-epi-oleanolic acid. A further new triterpene 3α,27-dihydroxy-12-oleanene was also isolated but its activity could not be determined due to paucity of material. In addition, three known triterpenes have been isolated for the first time form this species. NEW TRITERPENES ISOLATION FROM P. RUBRA 13α,27-dihydroxy-12-oleanene(47) Phytochemistry (In press).************ 2Rubrino948) Fitoterapia(In Press) ********************* The compound has been found to be active against two G(+) and two G(-) organisms, namely Bacillus anthracis, Corynebacterium pseudodiphthericum, Pseudomonas aeruginosa and Pseudomonas pseudomalliae. It also showed antitumor activity causing 54% reduction in tumor formation as against DMSO which was devoid of any inhibitory activity. 36α-dihydroxy-3-epi-oleanene acid(49) Phytochemistry(In press)************ TRITERPENES ISOLATION FRO THE FIRST TIME FROM P. RUBRA 1Taraxasteryl acetate(50) 2Cycloart-22-ene-3α,25-diol(51) 3Oleanolic acid(52) The part B of the thesis describes studies on the chemical constituents of Calotropis procera which have resulted in the isolation and characterization of a new cardenolide, proceragenin and calotropenol, new triterpene of the amyrin series. NEW COMPOUNDS FROM C. PROCERA 1Proceragenin(31) Phytochemistry , 31(8), 2821(1992)************** Proceragenin showed strong antibacterial activity and was found to be active against six G(+) and five G(-) organism namely Micrococcus luteus, Aeromonas sobriae, Aeromonas caviae, Pseudomonas pseudomalliae, Escherichia coli, Streptococcus fecalis, Vibrio cholarae, Klebsiella peumoniae, Corynebacterium diphteriae and Bacillus subtilis. It also showed strong antitumor activity, causing 75% reduction in the tumor formation as against DMSO which was devoid of any activity. 2Calotiropenol(29) Fitoterapia(In press)************** The part C describes studies on the terpenoidal of Amberboa ramosa which resulted in the isolation of two new cycloartane type triterpenes, besides two known triterpenoids which have been for the first time from this plant. New triterpenes isolation from A. Ramosa 1Cycloart-25-ene-3β,(22R)22-diol(28) J. Nat. Prod.(In press)************** 2Cycloart-20-ene-3β,25-diol(19) J. Nat. Prod.(In press)******************* Triterpenes isolation for the fist time from A. Ramosa 1Cycloartanol(20) 2Cycloart-23-ene-3β,25-diol(21) The structural elucidation of all the compounds have been carried out through chemical studies as weel as modern spectroscopic methods including 2D NMR spectroscopy.

Item Type:Thesis (PhD)
Uncontrolled Keywords:calotropis procera, plumeria, amberboa ramose, medicinal plants, triterpenes, p. rubra, genus calotropis, genus amberboa, genus plumeria
Subjects:Physical Sciences (f) > Chemistry(f2)
ID Code:1116
Deposited By:Mr. Muhammad Asif
Deposited On:03 Jan 2007
Last Modified:04 Oct 2007 21:04

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