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Biomedical subjects

Yvonne C Martin

Publications and source records attributed to Yvonne C Martin.

3 recordsLinked to original sources

A bioavailability score.

Responding to a demonstrated need for scientists to forecast the permeability and bioavailability (F) properties of compounds before their purchase, synthesis, or advanced testing, we have developed a score that assigns the probability that a compound will have F > 10% in the rat. Neither the rule-of-five, log P, log D, nor the combination of the number of rotatable bonds and polar surface area successfully categorized compounds. Instead, different properties govern the bioavailability of compounds depending on their predominant charge at biological pH. The fraction of anions with >10% F falls from 85% if the polar surface area (PSA) is < or = 75 A(2), to 56% if 75 < PSA < 150 A(2), to 11% if PSA is > or = 150 A(2). On the other hand, whereas 55% of the neutral, zwitterionic, or cationic compounds that pass the rule-of-five have >10% F, only 17% of those that fail have > 10% F. This same categorization distinguishes compounds that are poorly permeable from those that are permeable in Caco-2 cells. Further validation is provided with human bioavailability values from the literature.

Animals↗

Do structurally similar molecules have similar biological activity?

To design diverse combinatorial libraries or to select diverse compounds to augment a screening collection, computational chemists frequently reject compounds that are > or =0.85 similar to one already chosen for the combinatorial library or in the screening set. Using Daylight fingerprints, this report shows that for IC(50) values determined as a follow-up to 115 high-throughput screening assays, there is only a 30% chance that a compound that is > or = 0.85 (Tanimoto) similar to an active is itself active. Although this enrichment is greater than that found with random screening and docking to three-dimensional structures, this low fraction of actives within similar compounds occurs not only because of deficiencies in the Daylight fingerprints and Tanimoto similarity calculations but also because similar compounds do not necessarily interact with the target macromolecule in similar ways. The current study emphasizes the statistical or probabilistic nature of library design and that perfect results cannot be expected.

Combinatorial Chemistry Techniques↗

Ligand binding to domain-3 of human serum albumin: a chemometric analysis.

A detailed chemometric analysis of ligand binding to domain-3A of human serum albumin is described. NMR and fluorescence data on a set of 889 chemically diverse compounds were used to develop a group contribution model based on 74 chemical fragments that is in good agreement with the experimental data (R2 = 0.94, Q2 = 0.90). The structural descriptors used in this analysis comprise a convenient look-up table for quantitatively estimating the effect that a particular group will have on albumin binding. This information can be valuable for optimizing a particular series of compounds for drug development.

Binding Sites↗