Biomedical subjects
Publications and source records attributed to J R Hanson.
ent-19-Hydroxykaur-16-en-15-one is transformed to ent-3 beta,16 beta,19-trihydroxykauran-15-one by Cephalosporium aphidicola. The structure of this metabolite was established by X-ray crystallography.
The biotransformation of ent-16beta-17-epoxy-7 alpha-hydroxykaurane by Gibberella fujikuroi affords ent-7 alpha,11 alpha,16 beta,17-tetrahydroxykaurane and ent-7 alpha, 9 alpha, 16 beta, 17-tetrahydroxykaurane. These results indicated that the presence of the 16 alpha, 17-diol group, into which the 16 alpha, 17-epoxy is transformed in the medium, inhibits oxidation at C-19 and favours hydroxylation at C-11(beta). Incubation of ent-16 beta, 17-epoxykauran-19-oic acid, via the 16 alpha, 17-diol, gave the 7-aldehyde of 16 alpha, 17-dihydroxy-GA12.
The fungus, Cephalosporium aphidicola, has been shown to hydroxylate progesterone predominantly at the 6 beta- and 11 alpha-positions. Minor metabolites include testosterone acetate, the 20(R)-alcohol and 12 beta, 17 alpha-dihydroxy-progesterone. The sequence involves hydroxylation at 11 alpha and then 6 beta. The hydroxylations of 11 alpha- and 17 alpha-hydroxyprogesterone and of 9 beta, 10 alpha-retroprogesterone have also been examined in the light of these results.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
15-Oxosteviol, postulated to be the mutagenic metabolite of steviol, was observed to be non-mutagenic in preliminary experiments using a number of different systems. Repetition of the original experiment in Salmonella TM677 failed to show any significant induction of 8-azaguanine resistant mutants by 15-oxosteviol even when the number of bacteria tested was greatly increased. Examination of the earlier positive result showed that it could not be justified from the data and revealed a commonly applied way of mishandling data obtained with the TM677 system.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.