Tetrahydropiperine and piperine

A series of piperine derivates (1-19) have been designed, synthesized and evaluated in vitro for their monoamine oxidase (MAO) A and B inhibitory activity and selectivity. It is worth noting that most of the small amine moieties substituted on the piperidine ring proved to be potent and selective inhibitors of MAO-B rather than of MAO-A. 5-(3,4-methylenedioxyphenyl)-2E,4E-pentadienoic acid n-propyl amide (3) showed the greatest MAO-B inhibitory activity (IC(50)(MAO-B)=0.045 μM) and good selectivity (IC(50)(MAO-A)=3.66 μM). The conjugated double bond and carbonyl group of piperine are proved to be an essential feature for piperine and related alkylamides to exhibit MAO-inhibitory activity. Binding mode of the titled compounds was predicted using FlexX algorithm. The design and optimization of novel small molecule monoamine oxidase inhibitors will be guided by the results of this report.

Topics: Alkaloids; Benzodioxoles; Humans; Inhibitory Concentration 50; Models, Molecular; Monoamine Oxidase; Monoamine Oxidase Inhibitors; Piperidines; Polyunsaturated Alkamides; Protein Binding; Protein Structure, Tertiary; Structure-Activity Relationship

A series of natural and synthetic piperine amides were evaluated for activity on the human TRPV1 expressed in HEK293 cells. The agonistic effect of piperine amides was mainly dependent on the length of the carbon chain. Structural changes of double bonds and stereochemistry in the aliphatic chain of these compounds did not change their potency or efficacy, indicating that increased rigidity or planarity of the piperine structure does not affect the activity. The opening of the methylenedioxy ring or changes in the heterocyclic ring of the piperine molecule reduced or abolished activity. Furthermore, inactive compounds did not display functional antagonistic activity.

Topics: Alkaloids; Amides; Benzodioxoles; Capsaicin; Cell Line; Dose-Response Relationship, Drug; Humans; Molecular Structure; Piperidines; Polyunsaturated Alkamides; Spectrometry, Fluorescence; TRPV Cation Channels

Quantitative structure activity relationship (QSAR) analysis of piperine analogs as inhibitors of efflux pump NorA from Staphylococcus aureus has been performed in order to obtain a highly accurate model enabling prediction of inhibition of S. aureus NorA of new chemical entities from natural sources as well as synthetic ones. Algorithm based on genetic function approximation method of variable selection in Cerius2 was used to generate the model. Among several types of descriptors viz., topological, spatial, thermodynamic, information content and E-state indices that were considered in generating the QSAR model, three descriptors such as partial negative surface area of the compounds, area of the molecular shadow in the XZ plane and heat of formation of the molecules resulted in a statistically significant model with r(2)=0.962 and cross-validation parameter q(2)=0.917. The validation of the QSAR models was done by cross-validation, leave-25%-out and external test set prediction. The theoretical approach indicates that the increase in the exposed partial negative surface area increases the inhibitory activity of the compound against NorA whereas the area of the molecular shadow in the XZ plane is inversely proportional to the inhibitory activity. This model also explains the relationship of the heat of formation of the compound with the inhibitory activity. The model is not only able to predict the activity of new compounds but also explains the important regions in the molecules in quantitative manner.

Topics: Alkaloids; Anti-Bacterial Agents; Bacterial Proteins; Benzodioxoles; Computer Simulation; Models, Chemical; Models, Molecular; Multidrug Resistance-Associated Proteins; Piperidines; Polyunsaturated Alkamides; Quantitative Structure-Activity Relationship; Software; Staphylococcus aureus

Based on our recent findings that piperine is a potent Staphylococcus aureus NorA efflux pump inhibitor (EPI), 38 piperine analogs were synthesized and bioevaluated for their EPI activity. Twenty-five of them were found active with potentiating activity equivalent or more than known EPIs like reserpine, carsonic acid and verapamil. The inhibitory mechanism of the compounds was confirmed by efflux inhibition assay using ethidium bromide as NorA substrate. The present communication describes the synthesis, bioevaluation and structure related activity of these efflux pump inhibitors.

Topics: Alkaloids; Anti-Bacterial Agents; Bacterial Proteins; Benzodioxoles; Ciprofloxacin; Enzyme Inhibitors; Ethidium; Microbial Sensitivity Tests; Multidrug Resistance-Associated Proteins; Nucleic Acid Synthesis Inhibitors; Piperidines; Polyunsaturated Alkamides; Staphylococcus aureus

We describe herein an evaluation of trypanocidal effects of the natural alkaloid piperine and twelve synthetic derivatives against epimastigote and amastigote forms of the protozoan parasite Trypanosoma cruzi, the causative agent of the incurable human disease, Chagas' disease. The results obtained point to piperine as a suitable template for the development of new drugs with trypanocidal activity.

Topics: Alkaloids; Animals; Benzodioxoles; Cells, Cultured; Chagas Disease; Dose-Response Relationship, Drug; Drug-Related Side Effects and Adverse Reactions; Humans; Inhibitory Concentration 50; Parasitic Sensitivity Tests; Piperidines; Polyunsaturated Alkamides; Trypanocidal Agents; Trypanosoma cruzi