N-hexane Soluble Fraction Research Articles

Analysis of n-hexane Soluble Fraction of Yubari Coal Tar Pitch and its Structural Analysis

Although the method of structural analysis using NMR has been greatly developped recently, there remains some doubts whether its results represent true mean structure of compounds contained in the sample. The authors aimed to confirm this point.n-hexane soluble part of Yubari coal tar pitch was fractionated by GPC and alumina chromatography and each fraction was analysed by UV and GC-Mass. The mean structure was calculated from these results of analysis and this value was compared with the value from the structural analysis of NMR.This comparison gave a quite satisfactory result . From this it can be said that structural analytical indices represent very well the mean structure for such sample as the one which is not polymer and has low oxygen, nitrogen or sulfur content.

Secondary Metabolites from <i>Bryophyllum daigremontianum</i>

A total of four compounds were isolated from the n-hexane soluble fraction of a methanolic extract of the whole plant of Bryophyllum daigremontianum. The structures of the isolated compounds were elucidated as 11-oxo-epi-β-amyrin (1), 21-dehydrodesmosterol (2), 3,4-dihydroxy-cis-cinnamic acid (3), and p-hydroxy-benzaldehyde (4) by high field NMR analyses as well as by comparison with structurally related compounds. Key words: Bryophyllum daigremontianum, Crassulaceae, 11-oxo-epi-β-amyrin, 21-dehydrodesmosterol, 3,4-dihydroxy-cis-cinnamic acid, p-hydroxybenzaldehyde. doi: 10.3329/dujps.v7i2.2169 Dhaka Univ. J. Pharm. Sci. 7(2): 141-144, 2008 (December)

Chemical and Biological Investigations of <i>Samanea saman</i> (Jacq.) Merr.

Two compounds namely lupeol (1) and epilupeol (2) were isolated from n-hexane soluble fraction of crude methanol extract of the powdered whole plant of Samanea saman Merr. for the first time. The structures of the isolated compounds were established by extensive analyses of their high resolution NMR spectral data as well as co- TLC with authentic samples. In our preliminary screening, the n-hexane, carbon tetrachloride, and dichloromethane soluble fractions of the crude methanolic extract of S. saman were subjected to antimicrobial activity and brine shrimp lethality bioassay. The carbon tetrachloride soluble partitionate of the methanol extract exhibited mild to moderate antimicrobial activity and strong cytotoxicity having LC50 of 0.831μg/ml. Key words: Samanea saman; Leguminosae; lupeol; epilupeol; antimicrobial activity; brine shrimp lethality bioassay. DOI: http://dx.doi.org/10.3329/dujps.v9i2.7882 Dhaka Univ. J. Pharm. Sci. 9(2): 69-73, 2010 (December)