Journal of Computer-Aided Molecular Design

, Volume 20, Issue 12, pp 763–771 | Cite as

A marriage made in torsional space: using GALAHAD models to drive pharmacophore multiplet searches

Original Paper


Pharmacophore multiplets are useful tools for 3D database searching, with the queries used ordinarily being derived from ensembles of random conformations of active ligands. It seems reasonable to expect that their usefulness can be augmented by instead using queries derived from single ligand conformations obtained from aligned ligands. Comparisons of pharmacophore multiplet searching using random conformations with multiplet searching using single conformations derived from GALAHAD (a genetic algorithm with linear assignment for hypermolecular alignment of datasets) models do indeed show that, while query hypotheses based on random conformations are quite effective, hypotheses based on aligned conformations do a better job of discriminating between active and inactive compounds. In particular, the hypothesis created from a neuraminidase inhibitor model was more similar to half of 18 known actives than all but 0.2% of the compounds in a structurally diverse subset of the World Drug Index. Similarly, a model developed from five angiotensin II antagonists yielded hypotheses that placed 65 known antagonists within the top 0.1–1% of decoy databases. The differences in discriminating power ranged from 2 to 20-fold, depending on the protein target and the type of pharmacophore multiplet used.


GALAHAD Molecular alignment Pharmacophore Pharmacophore multiplets Tuplets Virtual screening 



Angiotensin II


Chapman and Hall Dictionary of Pharmaceutical Agents


Genetic algorithm


Genetic automated molecular overlays


Receiver Operating Characteristic


World Drug Index


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Copyright information

© Springer Science+Business Media, LLC 2006

Authors and Affiliations

  1. 1.Informatics Research CenterTripos Inc.St. LouisUSA

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