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Biomedical subjects

R H Willis

Publications and source records attributed to R H Willis.

6 recordsLinked to original sources
PubMed2001

Identification of a new human lens UV filter compound.

A new UV filter compound, 4-(2-amino-3-hydroxyphenyl)-4-oxobutanoic acid O-diglucoside, has been identified in human lenses. The structure suggests that it is a further metabolic product of the second most abundant UV filter compound, 4-(2-amino-3-hydroxyphenyl)-4-oxobutanoic acid O-glucoside. Quantification studies on the new compound show that it decreases towards zero in both the nucleus and cortex as a function of age. The discovery of this novel disaccharide completes the identification of the major UV filter compounds present in the human lens.

Adolescent↗
PubMed1997

Application of a radioreceptor assay to the screening and characterisation of compounds from marine organisms with activity at the phorbol ester binding site of protein kinase C.

Protein kinase C is a ubiquitous enzyme with a key role in cellular function, making it an attractive drug target. Utilising a competitive binding assay for the phorbol ester binding site of the enzyme in a rat brain membrane preparation, screening was undertaken on 686 marine macroorganisms representing a broad range of taxa and environments from throughout Australasia. Of these extracts from 28 organisms significantly inhibited [3H]phorbol dibutyrate binding, while two samples enhanced binding. Sponges and echinoderms were particularly well represented in the active specimens. A combination of taxonomic and elution information for individual leads provided a rationale for dereplication and prioritisation. Utilising assay-guided purification, the identity of active compounds from the sponge Agelas axifera was examined in detail. The previously described compounds, the agelasines, were identified. The screening and characterisation methods described provide a method for readily identifying novel probes for protein kinase C.

Animals↗
PubMed1997

BRS1, a C30 bis-amino, bis-hydroxy polyunsaturated lipid from an Australian calcareous sponge that inhibits protein kinase C.

In the course of screening for activity at the phorbol ester binding site of protein kinase C, activity was identified within an unidentified calcareous sponge (class Calcarea) collected in the central region of the Great Barrier Reef off the north-east coast of Australia. Using high-performance liquid chromatographic fractionation guided by activity at the enzyme, the C30 polyunsaturated lipid was isolated and its structure assigned on the basis of spectroscopic analysis. The compound was given the trivial name BRS1. It exhibited a 50% effective concentration for inhibiting phorbol ester binding of 9 microM and for inhibiting enzymic activity of 98 microM. This compound represents a novel protein kinase C inhibitor.

Amino Alcohols↗