ABSTRACT
Piperine is a component of Piper nigrum (Black pepper). It is well known in ayurvedic formulations. Piperine is a bioenhancer as it reduces the activity of drug-metabolizing enzymes in rodents and thereby enhancing the plasma concentrations of several drugs, including the Pglycoprotein substrates. Therefore, it is of interest to understand the molecular docking interactions of piperine with several cell cycle proteins such as Cyclin dependent kinase 2 (CDK2), Cyclin-dependent kinase 4 (CDK4), Cyclin D and Cyclin T for further consideration in drug discovery related to oral cancer.
ABSTRACT
Electron-transfer(ET) from organic sulfides to excited state rhenium(I)-based heteroleptic tricarbonyl complexes [Re(bpy)(CO)(3)(py)](+) (I) and [Re(bpy)(CO)(3)(ind))](+) (II) in acetonitrile solution is facile and luminescence quenching constants, k(q), are in the range 10(5)-10(8) M(-1)s(-1). The detection of the sulfide radical cation in this system using time-resolved absorption spectroscopy is a direct evidence for the ET nature of the reaction. The k(q) values for the quenching of Re(I)-complexes with organic sulfides are analyzed with a scheme involving rate controlling electron transfer process. The measured rate constants for the electron transfer (ET) reaction are close to the values calculated from Marcus theory.
