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Biomedical subjects

R K Hill

Publications and source records attributed to R K Hill.

At least 19 recordsLinked to original sources

Chemistry of zerumbone. 2. Regulation of ring bond cleavage and unique antibacterial activities of zerumbone derivatives.

Further investigation of the chemistry of the eleven-membered cyclic sesquiterpene, zerumbone, the major component of the wild ginger, Zingiber zerumbet Smith, has revealed a new selective epoxidation process, a further example of a novel Favorskii-initiated double ring contraction, and a regiospecific fragmentation of zerumbone dibromide derivatives. Several zerumbone derivatives were found to be selective inhibitors of the growth of gram-positive bacteria.

Anti-Bacterial Agents↗

Stereospecificity of the enzymatic dehydrogenation in the biosynthesis of 3-ethylidene-L-azetidine-2-carboxylic acid from isoleucine by Streptomyces cacaoi.

(2RS,3S,4S)-[2-14C,4-3H]Isoleucine and (2S,3S,4R)-[U-14C,4-3H]isoleucine have been prepared by stereospecific syntheses. The addition of these substrates to Streptomyces cacaoi led to the isolation of polyoxins from which 3-ethylidene-L-azetidine-2-carboxylic acid was isolated by hydrolysis. The pro-R hydrogen at C-4 of isoleucine was lost and the pro-S hydrogen was retained in the biosynthesis of 3-ethylidene-L-azetidine-2-carboxylic acid. These results indicate that the enzymatic dehydrogenation of isoleucine to form 3-ethylidene-L-azetidine-2-carboxylic acid involves the antiperiplanar elimination of the hydrogen at C-3 and the pro-R hydrogen at C-4.

Azetidinecarboxylic Acid↗

Quality assurance in ambulatory care.

Many of the methods for evaluating the quality of ambulatory care are costly, cumbersome, and possibly counterproductive. Major developments in evaluating the quality of the doctor-patient relationship are needed before a general assessment of the quality of ambulatory care is possible. Nonetheless, limited reviews based on insurance claims data can efficiently improve certain aspects of ambulatory care.

Ambulatory Care↗