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Ashraf T Khalil

Publications and source records attributed to Ashraf T Khalil.

3 recordsLinked to original sources

Secoiridoid glycoside and alkaloid constituents of Hydrangea chinensis.

A new secoiridoid glycoside, hydrachoside A (1), along with 14 known compounds, was isolated from the leaves of Hydrangea chinensis. The absolute stereochemistry of the side chain attached to C-15 on the secoiridoid glycoside hydrangenoside E (2) was determined by NMR spectral analysis. The structures of compounds 1 and 2 were elucidated on the basis of spectral data. The previously reported structure, hydrachine A (3), was revised as its epimer, (-)-neodichroine (4), a new compound.

Alkaloids↗

Limonoids from Citrus reticulata.

The seeds of Citrus reticulata afforded the new limonoid derivative, isolimonexic acid methyl ether, in addition to the previously isolated limonin, deacetylnomilin, obacunone and ichangin. The structure elucidation was achieved primarily through 1D and 2-D-NMR analyses. The marginal antimalarial activity of isolimonexic acid methyl ether is reported.

Antimalarials↗

Cytotoxic benzophenanthridine and benzylisoquinoline alkaloids from Argemone mexicana.

Fractionation of the chloroform extract from the aerial part of Argemone mexicana led to the isolation of two benzophenanthridine-type alkaloids, N-demethyloxysanguinarine and pancorine; three benzylisoquinoline-type alkaloids, (+)-1,2,3,4-tetrahydro-1-(2-hydroxymethyl-3,4-dimethoxyphenylmethyl)-6,7-methylenedioxyisoquinoline, (+)-higenamine and (+)-reticuline. Among them, N-demethyloxysanguinarine is a new compound, and (+)-1,2,3,4-tetrahydro-1-(2-hydroxymethyl-3,4-dimethoxyphenylmethyl)-6,7-methylenedioxy-isoquinoline was isolated form a natural source for the first time, to which was assigned a trivial name, (+)-argenaxine. In addition, six known non-alkaloidal compounds were also isolated and identified. All compounds were characterized on the basis of their spectral data and chemical evidences. Some isolated alkaloids from this species were evaluated for their cytotoxicity to human nasopharyngeal carcinoma (HONE-1) and human gastric cancer (NUGC) cell lines. Chelerythrine was found to exhibit significant activity against NUGC cell line, while angoline inhibited both types. (+)-Argenaxine showed moderate activity against the NUGC cell line.

Alkaloids↗