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Biomedical subjects

M Hoshi

Publications and source records attributed to M Hoshi.

At least 343 records · Page 19Linked to original sources
PubMed1973

2,3-Erythro-dihydroxyhexacosanoic acid and homologs: isolation from yeast cerebrin phosphate and determination of their structures.

Homologs of methyl esters of very polar fatty acids were obtained by methanolysis of cerebrin phosphate isolated from baker's yeast. The major ester component was isolated by preparative gas-liquid chromatography and was found to be 2,3-dihydroxyhexacosanoic acid as deduced from the mass spectra of its trimethylsilyl ether and isopropylidene derivative, reaction with periodate, and comparison of its chromatographic behavior with that of synthetic erythro- and threo-dihydroxy acids. Its infrared spectrum supported the above conclusions. From their retention times by gas-liquid chromatography, the homologs were found to be saturated, unbranched 2,3-dihydroxy fatty acids with 24-27 carbon atoms. The synthesis of the new fatty acids, erythro- and threo-2,3-dihydroxyhexacosanoic acids, is also reported. A method for separating trans-2-hexacosenoic acid, a key intermediate of the above synthesis, and its isomer, trans-3-hexacosenoic acid, both formed by dehydrobromination of 2-bromohexacosanoic acid, is also described.

Chromatography, Gas↗
PubMed1973

Esterification of fatty acids at room temperature by chloroform-methanolic HCl-cupric acetate.

A new procedure for the preparation of methyl esters from free fatty acids under mild conditions was investigated. Free fatty acids are dissolved in a mixture of chloroform-methanolic HCl-cupric acetate and kept at room temperature for 30 min for complete esterification. The method is suitable for esterification of long-chain acids, such as 18:0, and for very long chain acids, such as 24:0. Fatty acids from brain glycerophosphatides, which included a high concentration of polyenes such as 20:4 (n - 6), 22:4 (n - 6), and 22:6 (n - 3), were also esterified by the same procedure, and neither artifact formation nor loss of unsaturated acids was observed.

Carbon Isotopes↗