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Biomedical subjects

N S Radin

Publications and source records attributed to N S Radin.

At least 145 records · Page 8Linked to original sources
PubMed1968

6-acyl galactosyl ceramides of pig brain: structure and fatty acid composition.

Two glycolipids were isolated from pig brain and were shown to be the fatty acid esters of kerasin and cerebron in which the second fatty acid moiety is attached to the 6-position of the galactose. The point of attachment was shown in two ways: by permethylation and by cleavage with periodate. Methanolysis of the permethylated cerebroside esters yielded O-methyl sphingosines, methyl esters of nonhydroxy or 2-methoxy acids, and methyl 2,3,4-trimethyl galactoside. Cleavage of the cerebron ester with periodate, followed by treatment with sodium borohydride and dilute HCl, yielded ceramide plus 1-monoglyceride. The ester-linked fatty acids were primarily 16:0, 18:0, and 18:1, while the amide-linked fatty acids showed the wide assortment of chain lengths typical of brain cerebrosides. The methylation step, with silver oxide and methyl iodide, yielded two derivatives with the cerebroside esters, but the structural explanation for the difference was not elucidated. The galactose in the cerebron ester was shown to exist in the beta-pyranoside form.

Animals↗
PubMed1967

Spot applicator for thin-layer plates.

A device that lowers a micropipet into position just above a thin-layer plate is described. Use of a self-filling pipet and foot-operated bellows allows one to apply many portions of a sample to the same point at high speed without damaging the adsorbent coating.

Chromatography, Thin Layer↗
PubMed1966

Decarboxylation of 2-keto fatty acids by brain.

An enzyme system consisting of washed acetone powder of pig brain, adenosine triphosphate, nicotinamide adenine dinucleotide, magnesium, fumaric acid, and ascorbic acid was found to catalyze the oxidative decarboxylation of 2-ketostearic acid. The products were carbon dioxide and heptadecanoic acid. Washing the enzyme powder with ethylene-diaminetetraacetate and other chelating agents destroyed the activity. Further properties of the enzyme system are described. It is believed that this enzyme system accounts in part for the 1-carbon degradation route for brain fatty acids.

Adenosine Triphosphate↗
PubMed1966

Determination of brain gangliosides by determination of ganglioside stearic acid.

A new method is described for the determination of brain gangliosides by measuring stearic acid, the chief acid of gangliosides, in an appropriately purified brain extract. The method includes extraction of tissue with chloroform-methanol, extraction of gangliosides from the extract with 0.1 M KCl, evaporation of the aqueous phase, methanolysis, and gas-liquid chromatography of the resultant methyl esters with a double internal standard. The method depends on the simple composition of ganglioside fatty acids (80% stearic acid) and allows determination of less than 0.05 micromole of gangliosides. Interfering lipids are removed from the ganglioside extract by washing with chloroform-methanol-water. The effects of contamination with nonlipid N-acetylneuraminic acid are avoided.

Animals↗
PubMed1966

Cerebroside galactosidase of brain.

The galactoside bond in cerebroside was found to be cleaved by an enzyme in rat and pig brain. Emulsified stearoyl-(14)C psychosine was used as the substrate and the extent of cleavage was studied by isolating and counting the stearoyl sphingosine (ceramide) formed. The reaction products, ceramide and galactose, were characterized by column and thin-layer chromatography. Cerebroside containing galactose-(3)H was also used to show liberation of galactose. Cholic acid was found to be required for activation of the enzyme, which has a pH optimum of 4.5. Similar cerebrosidase activity was found in spleen, kidney, and lung of rat; liver and heart showed very slight activity. The partially purified enzyme from pig brain also formed ceramide from ceramide lactoside, ceramide glucoside, and cerebronoyl psychosine. The enzyme was active toward o-nitrophenyl galactoside and could be fractionated by Sephadex chromatography into a fraction active toward the nitrophenyl galactoside only and a fraction active toward both this substrate and ceramide galactoside. Human spleen, normal and Gaucher, exhibited cerebrosidase activity.

Animals↗