Insight into Structure Activity Relationship of DPP-4 Inhibitors for Development of Antidiabetic Agents.

This article sheds light on the various scaffolds that can be used in the designing and development of novel synthetic compounds to create DPP-4 inhibitors for the treatment of type 2 diabetes mellitus (T2DM). This review highlights a variety of scaffolds with high DPP-4 inhibition activity, such as pyrazolopyrimidine, tetrahydro pyridopyrimidine, uracil-based benzoic acid and esters, triazole-based, fluorophenyl-based, glycinamide, glycolamide, ß-carbonyl 1,2,4-triazole, and quinazoline motifs. The article further explains that the potential of the compounds can be increased by substituting atoms such as fluorine, chlorine, and bromine. Docking of existing drugs like sitagliptin, saxagliptin, and vildagliptin was done using Maestro 12.5, and the interaction with specific residues was studied to gain a better understanding of the active sites of DPP-4. The structural activities of the various scaffolds against DPP-4 were further illustrated by their inhibitory concentration (IC50) values. Additionally, various synthesis schemes were developed to make several commercially available DPP4 inhibitors such as vildagliptin, sitagliptin and omarigliptin. In conclusion, the use of halogenated scaffolds for the development of DPP-4 inhibitors is likely to be an area of increasing interest in the future.

Triazole scaffold-based DPP-IV Inhibitors for the management of Type-II Diabetes Mellitus: Insight into Molecular Docking and SAR.

Diabetes mellitus, characterized as a chronic metabolic disorder or a polygenic syndrome; is increasing at a very fast pace among every group of the population worldwide. It arises due to the inability of the body to produce enough insulin (the hormone responsible for controlling blood sugar levels) or inability to utilize the insulin, leading to hyperglycaemic condition, which, if left uncontrolled gives rise to chronic microvascular and macrovascular complications like retinopathy, neuropathy, nephropathy, coronary artery disease, cognitive impairment, etc. Several therapeutic approaches are available for the treatment of diabetes; among which dipeptidyl peptidase (DPP-IV) inhibitors (gliptins) hold a significant place. DPP-IV is a multifunctional enzyme or a serine exopeptidase that plays an imperative role in cleaving bioactive molecules. DPP-IV causes the breakdown of incretin hormone (GLP-1: Glucagon-like peptide 1 and GIP: Glucose-dependent insulinotropic peptide) that is essential for controlling glycaemic levels in the body. Inhibition of DPP-IV enzyme (DPP-IV inhibitors: Sitagliptin, Saxagliptin, Linagliptin, Alogliptin) prevents this breakdown, thereby controlling blood glucose levels and saving the patients from deleterious effects of prolonged hyperglycaemic conditions. Triazole-based DPP-IV inhibitors are a significant class of drugs used to treat Type 2 diabetes mellitus in a dose-dependent manner. Clinical trials have demonstrated their efficacy as monotherapy or in combination with other antidiabetic agents. This review highlights the molecular docking studies and structure-activity relationship of potential synthetic derivatives that may act as lead molecules for future drug discovery and yield drug molecules with enhanced efficacy, potency and reduced toxicity profile.

Image analysis of PVC / TiO2 nanocomposites SEM micrographs.

The present paper deals with image analysis of Scanning Electron Microscope (SEM) micrographs of PVC / TiO2 nanocomposites prepared through solution casting technique at different wt% of TiO2 nanofillers dispersed within the PVC matrix. The qualitative and quantitative dispersion of TiO2 nanofillers is estimated through the proposed algorithm based on global threshold obtained from Otsu's method. The PVC-TiO2- PVC molecular region map and TiO2 nanofillers dispersion maps are obtained by background elimination technique with predefined threshold value and a global threshold value, respectively. The particle size distribution histograms are obtained in terms of TiO2 nanofillers population versus available PVC/TiO2 matrix areal spread. This study is carried out to correlate qualitative and quantitative dispersion of TiO2 nanofillers within the PVC matrix with the variation of specimen properties accordingly.