Chemistry of some novel friedelane triterpenoids from Kokoona Zeylanica THW.
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Date
1980-10
Authors
Nanayakkara, N. P. Dhammika
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Publisher
University of Peradeniya
Abstract
This thesis is composed of two parts. The first part consists of the isolation and structure elucidation of eleven friedelane derivatives from Kokoona zeylanica Thw. of the family Celastraceae. Of these, eight compounds were found to be new, belonsing to three series according to their oxyrenation pattern. The kokoondiol series consisted of three compounds namely kokooniol (friedelan-4-one-27-01), kokoononol(friedelan-3,?1-dione~-27-01) and kokoonol (friedelan-3-one-21a,27-diol); while the zeylanol series contained three comrounds, zeylanol (friedelan-3-one- 6p-ol), zeylanonol (friedelan-3,?1-dione-6f-o1) and zevlandiol (friedelan-3-one-6P,21P-diol); kokzeylanol (frieéelan-3-one-6p, e7-diol) and kokzeylanonol(friedelan-3,21-dione-6p,27-diol) constituted the third series, the ‘okzeylenol series.
The compounds belonsing to each series were coemically interrelated and their structures were determined with the help of srectrosconic data. FPhotolysis of those containing the Pl-keto rroup sided not only the locstion of this group but also the determination of the C-27 hycroxy function. In their chemical correlstions two recently described reiuction methods were applied to deoxyrenate S-h roxy,cl-hydroxy and 2?-hydroxy function.
In the second part of this thesis the assirnment of the C-13 n.m.r. siennls of nine compounds friedelin, frieéelan-2l-one, friedelan-6-one, friedelan-27-ol, friedelen-3.21-dione, friedelan-3,6-dione, friedelan-3,6,°l-trione, friedelan-3- one-27-ol (kokoonol), friedelan-3,21-dione-27-o1 (kokoononol1) are discussed. The partially relaxed fourier transform (PFRT) Spectra and lanthanide induced shift (LIS) data were used in the assignment of the carbon atoms of these comrounds.
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Keywords
Chemistry , Medicinal plants