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Biomedical subjects

J D Phillipson

Publications and source records attributed to J D Phillipson.

At least 73 records · Page 4Linked to original sources

Cascarosides A and B.

Electron-impact and field desorption mass spectrometry, together with NMR and circular dichroism spectroscopy, were used to confirm that cascarosides A and B are C-10 isomers of 8-O-(beta-D-glucopyranosyl)barbaloin. Several batches of cascarosides A and B were prepared and oxidatively hydrolyzed to aloe-emodin. The results are discussed in relation to the assay for cascara given in the European Pharmacopoeia, 1971.

Anthraquinones↗

Metabolic N-oxidation of atropine, hyoscine and the corresponding nor-alkaloids by guinea-pig liver microsomal preparations.

Incubation of guinea-pig liver microsomal preparations with atropine or hyoscine resulted in the formation of the corresponding nor-alkaloids and both isomers of atropine N-oxide from atropine and one isomer of hyoscine N-oxide from hyoscine. Separate incubations of guinea-pig liver microsomal preparations with nor-atropine and nor-hyoscine yielded the corresponding hydroxylamines. The N-oxide and hydroxylamine metabolites were identified by comparison of their t.l.c. behavior and m.x. with prepared compounds and also by their reduction to the corresponding tertiary or secondary amines.

Alkaloids↗

Chromatographic and spectroscopic methods for the identification of alkaloids from herbarium samples of the genus Uncaria.

A combination of thin-layer chromatography, gas-liquid chromatography, ultraviolet spectroscopy and mass spectrometry techniques for the alkaloid screening of herbarium samples of the genus Uncaria (Rubiaceae) is described. Some sixty alkaloids are distinguished by the screening procedure, and they represent heteroyohimbine, oxindole, roxburghine, simple beta-carboline, pyridino-indolo-quinolizidinone and gambirtannine types.

Alkaloids↗