In medicinal chemistry and molecular biology, a pharmacophore is an abstract description of molecular features that are necessary for molecular recognition of a ligand by a biological macromolecule. IUPAC defines a pharmacophore to be "an ensemble of steric and electronic features that is necessary to ensure the optimal supramolecular interactions with a specific biological target and to trigger (or block) its biological response". A pharmacophore model explains how structurally diverse ligands can bind to a common receptor site. Furthermore, pharmacophore models can be used to identify through de novo design or virtual screening novel ligands that will bind to the same receptor.
Typical pharmacophore features include hydrophobic centroids, aromatic rings, hydrogen bond acceptors or donors, cations, and anions. These pharmacophobic points may be located on the ligand itself or may be projected points presumed to be located in the receptor.
The features need to match different chemical groups with similar properties, in order to identify novel ligands. Ligand-receptor interactions are typically “polar positive”, “polar negative” or “hydrophobic”. A well-defined pharmacophore model includes both hydrophobic volumes and hydrogen bond vectors.
The process for developing a pharmacophore model generally involves the following steps:
Select a training set of ligands – Choose a structurally diverse set of molecules that will be used for developing the pharmacophore model. As a pharmacophore model should be able to discriminate between molecules with and without bioactivity, the set of molecules should include both active and inactive compounds.
Conformational analysis – Generate a set of low energy conformations that is likely to contain the bioactive conformation for each of the selected molecules.
Molecular superimposition – Superimpose ("fit") all combinations of the low-energy conformations of the molecules. Similar (bioisosteric) functional groups common to all molecules in the set might be fitted (e.g.
Cette page est générée automatiquement et peut contenir des informations qui ne sont pas correctes, complètes, à jour ou pertinentes par rapport à votre recherche. Il en va de même pour toutes les autres pages de ce site. Veillez à vérifier les informations auprès des sources officielles de l'EPFL.
vignette|Pharmacophore des antihistaminiques. Un pharmacophore est constitué par une partie pharmacologiquement active d'une molécule servant de modèle. Les pharmacophores sont donc des ensembles d'atomes actifs utilisés dans la conception de médicaments. Le pharmacophore est une représentation géométrique idéalisée, seule la modélisation en 3D peut permettre une utilisation optimale pour la création de nouveaux médicaments.
Virtual screening (VS) is a computational technique used in drug discovery to search libraries of small molecules in order to identify those structures which are most likely to bind to a drug target, typically a protein receptor or enzyme. Virtual screening has been defined as "automatically evaluating very large libraries of compounds" using computer programs. As this definition suggests, VS has largely been a numbers game focusing on how the enormous chemical space of over 1060 conceivable compounds can be filtered to a manageable number that can be synthesized, purchased, and tested.
Une relation quantitative structure à activité (en anglais : Quantitative structure-activity relationship ou QSAR, parfois désignée sous le nom de relation quantitative structure à propriété - en anglais : quantitative structure-property relationship ou QSPR) est le procédé par lequel une structure chimique est corrélée avec un effet bien déterminé comme l'activité biologique ou la réactivité chimique. Ainsi, l'activité biologique peut être exprimée de manière quantitative, comme pour la concentration de substance nécessaire pour obtenir une certaine réponse biologique.
Sitting at the crossroad of organic chemistry and medicine, this course outlines how an initial hit compound transitions into a lead candidate, and ultimately a drug, in the modern drug discovery worl