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Biomedical subjects

C J Brooks

Publications and source records attributed to C J Brooks.

At least 73 records · Page 4Linked to original sources

Sterols of scallop. Part II. Structure of unknown sterols by combination gas-liquid chromatography and mass spectrometry.

Four sterols, isolated from the scallop Pacopecten magellanicus have been identified as 24-nor-5alpha-cholest-22-en-3beta-ol; 24-norcholest-5-en-3beta-ol; 5alpha-cholest-22-en-3beta-ol; and (E) -24-propylidenecholest-5-en-3beta-ol. These bring to seventeen the total number of sterols identified in this marine mollusc. A fifth newly detected sterol, closely similar in its mass spectrometric properties is 22-cis and trans-cholesta-5, 22-dien-3beta-ol, was clearly distinguished from these by its shorter retention time by GLC.

Animals↗

Cholesterol oxidase. Further studies of substrate specificity in relation to the analytical characterisation of steroids.

The substrate specificity of cholesterol oxidase has been further examined with respect to the size and shape of the steroid 17beta-side-chain and oxygenation of the nucleus. The relatively unreactive 17-keto-delta5-3beta-hydroxysteroids were converted to satisfactory substrates by formation of the isopentyl- or benzyloximes. The results obtained have been used to illustrate further uses of the enzyme in the gas-phase analytical characterisation and selective oxidation steroids. Oxidations were studied by kinetic experiments, gas-liquid chromatography-mass spectrometry.

17-Ketosteroids↗

The isolation of cholest-5-ene-3beta,26-diol from human brain.

Cholest-5-ene-3beta,26-diol, isolated from human brain, was further characterized by oxidation to 3-oxocholest-4-en-26-ol and to 3-oxocholest-4-en-26-oic acid. Identification was achieved by comparison (by t.l.c., g.l.c. and g.l.c.-mass spectrometry) with corresponding reference compounds derived from kryptogenin.

Brain Chemistry↗