Synthesis, Biological Evaluation, and QPLD Studies of Piperazine Derivatives as Potential DPP-IV Inhibitors.

BACKGROUND: Diabetes mellitus is a serious global health issue, currently affecting 425 million people and is set to affect over 690 million people by 2045. It is a chronic disease characterized by hyperglycemia due to relative or absolute insulin hormone deficiency. Dipeptidyl peptidase- IV (DPP-IV) inhibitors are hypoglycemic agents augmenting the action of the incretin hormones that stimulate insulin secretion from the pancreatic beta cells. OBJECTIVE: In this study, synthesis and biological evaluation of seven piperazine derivatives 3a-g was carried out. METHODS: The synthesized molecules were characterized using proton-nuclear magnetic resonance, carbon-nuclear magnetic resonance, infrared spectroscopy and mass spectrometry. RESULTS: In vitro biological evaluation study showed comparable DPP-IV inhibitory activity for the targeted compounds ranging from 19%-30% at 100 µM concentration. Furthermore, the in vivo hypoglycemic activity of 3d was evaluated using streptozotocin-induced diabetic mice. It was found that compound 3d significantly decreased the blood glucose level when the diabetic group treated with 3d was compared to the control diabetic group. Quantum-Polarized Ligand Docking (QPLD) studies demonstrate that 3a-g fit the binding site of DPP-IV enzyme and form H-bonding with the backbones of R125, E205, E206, K554, W629, Y631, Y662, R669, and Y752. CONCLUSION: Piperazine derivatives were successfully found to be new scaffolds as potential DPP-IV inhibitors.

Identification of dipeptidyl peptidase IV inhibitors: virtual screening, synthesis and biological evaluation.

Inhibition of dipeptidyl peptidase IV is an important approach for the treatment of type-2 diabetes. In this study, we reported a multistage virtual screening workflow that integrated 3D pharmacophore models, structural consensus docking, and molecular mechanics/generalized Born surface area binding energy calculation to identify novel dipeptidyl peptidase IV inhibitors. After screening our in-house database, two hit compounds, HWL-405 and HWL-892, having persistent high performance in all stages of virtual screening were identified. These two hit compounds together with several analogs were synthesized and evaluated for in vitro inhibition of dipeptidyl peptidase IV. The experimental data indicated that most designed compounds exhibited significant dipeptidyl peptidase IV inhibitory activity. Among them, compounds 35f displayed the greatest potency against dipeptidyl peptidase IV in vitro with the IC50 value of 78 nm. In an oral glucose tolerance test in normal male Kunming mice, compound 35f reduced blood glucose excursion in a dose-dependent manner.

Discovery of new chemotype dipeptidyl peptidase IV inhibitors having (R)-3-amino-3-methyl piperidine as a pharmacophore.

Structures containing the (R)-3-amino-3-methyl piperidine unit as a new pharmacophore moiety have been shown to possess moderate inhibitory activity for DPP-4 with good pharmacokinetics profile. One of these compounds was found to have good oral bioavailability and PK/PD profile in ZF-rat.

Synthesis, biological assay in vitro and molecular docking studies of new imidazopyrazinone derivatives as potential dipeptidyl peptidase IV inhibitors.

A series of novel imidazopyrazinone derivatives were synthesized and evaluated with regard to their ability to inhibit dipeptidyl peptidase IV (DPP-IV) in vitro. Of these compounds (2R)-4-oxo-4-[2-(3-carbamoylbenzyl)-hexahydro-3-oxoimidazo [1,5-a]pyrazin-7(8H)-yl]-1-(2,4,5-trifluorophenyl)butan-2-amine fumaric acid (17h, IC(50)=78 nM) was shown to effectively inhibit the activity of the dipeptidyl peptidase IV enzyme. Molecular docking studies were also performed to illustrate the binding mode of compounds 15c and 17h. Favorable interactions were identified from the binding of inhibitor 15c with DPP-IV. By analogy to the binding mode of compound 15c, it seems that the introduction of a substituted benzyl moiety onto the imidazopyrazinone could remarkably improve the inhibitory activity of compound 17h.