Design, synthesis, biological screening, and molecular docking studies of piperazine-derived constrained inhibitors of DPP-IV for the treatment of type 2 diabetes

Synthetic Approaches to Novel DPP-IV Inhibitors-A Literature Review

Dipeptidyl peptidase IV (DPP-IV) is a serine protease whose inhibition has been an object of considerable interest in the context of developing novel treatments for type 2 diabetes mellitus. The development of novel DPP-IV inhibitors from natural or synthetic origin has seen a growing scientific interest in recent years, especially during the SARS-CoV-2 pandemic, when DPP-IV inhibitors were found to be of beneficial therapeutic value for COVID-19 patients. The present manuscript aims to summarize the most recent information on the synthesis of different DPP-IV inhibitors, emphasizing the various heterocyclic scaffolds that can be found in them. Special attention is devoted to DPP-IV inhibitors that are currently in clinical trials. Different synthetic approaches for the construction of DPP-IV inhibitors are discussed, as well as the most recent developments in the field.

Morpholine, Piperazine, and Piperidine Derivatives as Antidiabetic Agents

Diabetes mellitus is a severe endocrine disease that affects more and more people every year. Modern medical chemistry sets itself the task of finding effective and safe drugs against diabetes. This review provides an overview of potential antidiabetic drugs based on three heterocyclic compounds, namely morpholine, piperazine, and piperidine. Studies have shown that compounds containing their moieties can be quite effective in vitro and in vivo for the treatment of diabetes and its consequences.

Designing and computational analyzing of chimeric long-lasting GLP-1 receptor agonists for type 2 diabetes

Glucagon-like peptide-1 (GLP-1) is an intestinally derived incretin that plays a vital role in engineering the biological circuit involved in treating type 2 diabetes. Exceedingly short half-life (1-2 min) of GLP-1 limits its therapeutic applicability, and the implication of its new variants is under question. Since albumin-binding DARPin as a mimetic molecule has been reported to increase the serum half-life of therapeutic compounds, the interaction of new variants of GLP-1 in fusion with DARPin needs to be examined against the GLP-1 receptor. This study was aimed to design stable and functional fusion proteins consisting of new protease-resistant GLP-1 mutants (mGLP1) genetically fused to DARPin as a critical step toward developing long-acting GLP-1 receptor agonists. The stability and solubility of the engineered fusion proteins were analyzed, and their secondary and tertiary structures were predicted and satisfactorily validated. Molecular dynamics simulation studies revealed that the predicted structures of engineered fusion proteins remained stable throughout the simulation. The relative binding affinity of the engineered fusion proteins' complex with human serum albumin and the GLP-1 receptor individually was assessed using molecular docking analyses. It revealed a higher affinity compared to the interaction of the individual GLP-1 and HSA-binding DARPin with the GLP-1 receptor and human serum albumin, respectively. The present study suggests that engineered fusion proteins can be used as a potential molecule in the treatment of type 2 diabetes, and this study provides insight into further experimental use of mimetic complexes as alternative molecules to be evaluated as new bio-breaks in the engineering of biological circuits in the treatment of type 2 diabetes.

Heterocyclic compounds as a magic bullet for diabetes mellitus: a review

Diabetes mellitus (DM) is a major metabolic disorder due to hyperglycemia, which is increasing all over the world. From the last two decades, the use of synthetic agents has risen due to their major involvement in curing of chronic diseases including DM. The core skeleton of drugs has been studied such as thiazolidinone, azole, chalcone, pyrrole and pyrimidine along with their derivatives. Diabetics assays have been performed in consideration of different enzymes such as α-glycosidase, α-amylase, and α-galactosidase against acarbose standard drug. The studied moieties were depicted in both models: in vivo as well as in vitro. Molecular docking of the studied compounds as antidiabetic molecules was performed with the help of Auto Dock and molecular operating environment (MOE) software. Amino acid residues Asp349, Arg312, Arg439, Asn241, Val303, Glu304, Phe158, His103, Lys422 and Thr207 that are present on the active sites of diabetic related enzymes showed interactions with ligand molecules. In this review data were organized for the synthesis of heterocyclic compounds through various routes along with their antidiabetic potential, and further studies such as pharmacokinetic and toxicology studies should be executed before going for clinical trials.

Diabetes mellitus (DM) is a major metabolic disorder due to hyperglycemia, which is increasing all over the world.

A review upon medicinal perspective and designing rationale of DPP-4 inhibitors

Type 2 Diabetes Mellitus (T2DM) is one of the highly prevalence disorder and increasing day by day worldwidely. T2DM is a metabolic disorder, which is characterized by deficiency in insulin or resistance to insulin and thus increases the glucose levels in the blood. Various approaches are there to treat diabetes but still there is no cure for this disease. DPP-4 inhibitor is a privileged target in the field of drug discovery and provides various opportunities in exploring this target for development of molecules as antidiabetic agents. DPP-4 acts by inhibiting the incretin action and thus decreases the level of blood glucose by imparting minimal side effects. Sitagliptin, vildagliptin, linagliptin etc. are the different DPP-4 based drugs approved throughout the world for the treatment of diabetes mellitus. Cyanopyrrolidines, triazolopiperazine amide, pyrrolidines are basic core nucleus present in various DPP-4 inhibitors and has potential effects. In the past few years, researchers had applied various approaches to synthesize potent DPP-4 inhibitors as antidiabetic agent without side effects like weight gain, cardiovascular risks, retinopathy etc. This review will also emphasize the recent strategies and rationale utilized by researchers for the development of DPP-4 inhibitors. This review also reveals about the various other approaches like molecular modelling, ligand based drug designing, high throughput screening etc. are used by the various research group for the development of potential DPP-4 inhibitors.

Recent Medicinal Chemistry Approach for the Development of Dipeptidyl Peptidase IV Inhibitors

BACKGROUND

Diabetes, a metabolic disease, occurs due to a decreased or no effect of insulin on the blood glucose level. The current oral medications stimulate insulin release, increase glucose absorption and its utilization, and decrease hepatic glucose output. Two major incretin hormones like Glucose-dependent insulinotropic polypeptide (GIP) and glucagonlike peptide - 1 (GLP-1) stimulate insulin release after a meal, but their action is inhibited by enzyme dipeptidyl peptidase- IV.

OBJECTIVE

The activity of endogenous GLP-1 and GIP prolongs and extends with DPP IV inhibitors, which are responsible for the stimulation of insulin secretion and regulation of blood glucose level. DPP IV inhibitors have shown effectiveness and endurability with a neutral effect on weight as well as less chances of hypoglycemia in the management of type 2 diabetes. These journeys started from Sitagliptin (marketed in 2006) to Evogliptin (marketed in 2015, Korea).

CONCLUSION

Treatment of type 2 diabetes includes lifestyle changes, oral medications, and insulin. Newer and superior therapies are needed more than currently prescribed drugs. Various heterocyclic derivatives have been tried, but due to masking of DASH proteins, CYP enzymes, and hERG channel, they showed side effects. Based on these, the study has been focused on the development of safe, influential, selective, and long-lasting inhibitors of DPP IV.

Structural and biological survey of 7-chloro-4-(piperazin-1-yl)quinoline and its derivatives

The 7-chloro-4-(piperazin-1-yl)quinoline structure is an important scaffold in medicinal chemistry. It exhibited either alone or as hybrid with other active pharmacophores diverse pharmacological profiles such as: antimalarial, antiparasitic, anti-HIV, antidiabetic, anticancer, sirtuin Inhibitors, dopamine-3 ligands, acetylcholinesterase inhibitors, and serotonin antagonists. In the presented review, a comprehensive discussion of compounds having this structural core is surveyed and illustrated.

Synthesis of vildagliptin conjugated metal nanoparticles for type II diabetes control: targeting the DPP-IV enzyme

Diabetes is one of the most prevalent diseases worldwide.

Emergence of promising novel DPP-4 inhibitory heterocycles as anti-diabetic agents: A review

Diabetes has turned out to be an epidemic in the recent years all over the world, and today it has become a burden on the healthcare system. Over the years, with technological advancements, different classes of antidiabetic medications have emerged, like sulfonylureas, biguanides, alpha-glucosidase inhibitors, and thiazolidinediones, but these are often loaded with serious aftermaths like hypoglycemia, weight gain, cardiovascular and renal issues. Dipeptidyl peptidase-4 (DPP-4) inhibition is an exciting and new approach in the treatment of type-2 diabetes. DPP-4 inhibitors or "gliptins" are weight neutral, pose lesser risk of hypoglycemia, and provide a long-term post-meal glycemic control. In this review, an attempt has been made to investigate novel potential compounds that can be added to the existing list of anti-diabetic drugs.

Recent progress of the development of dipeptidyl peptidase-4 inhibitors for the treatment of type 2 diabetes mellitus

Diabetes is a fast growing chronic metabolic disorder around the world. Dipeptidyl peptidase-4 (DPP-4) is a new promising target during type 2 diabetes glycemic control. Thus, a number of potent DPP-4 inhibitors were developed and play a rapidly evolving role in the management of type 2 diabetes in recent years. This article reviews the development of synthetic and natural DPP-4 inhibitors from 2012 to 2017 and provides their physico-chemical properties, biological activities against DPP-4 and selectivity over dipeptidyl peptidase-8/9. Moreover, the glucose-lowering mechanisms and the active site of DPP-4 are also discussed. We also discuss strategies and structure-activity relationships for identifying potent DPP-4 inhibitors, which will provide useful information for developing potent DPP-4 drugs as type 2 diabtes treatments.

Computational Analysis of Gynura bicolor Bioactive Compounds as Dipeptidyl Peptidase-IV Inhibitor

The inhibition of dipeptidyl peptidase-IV (DPPIV) is a popular route for the treatment of type-2 diabetes. Commercially available gliptin-based drugs such as sitagliptin, anagliptin, linagliptin, saxagliptin, and alogliptin were specifically developed as DPPIV inhibitors for diabetic patients. The use of Gynura bicolor in treating diabetes had been reported in various in vitro experiments. However, an understanding of the inhibitory actions of G. bicolor bioactive compounds on DPPIV is still lacking and this may provide crucial information for the development of more potent and natural sources of DPPIV inhibitors. Evaluation of G. bicolor bioactive compounds for potent DPPIV inhibitors was computationally conducted using Lead IT and iGEMDOCK software, and the best free-binding energy scores for G. bicolor bioactive compounds were evaluated in comparison with the commercial DPPIV inhibitors, sitagliptin, anagliptin, linagliptin, saxagliptin, and alogliptin. Drug-likeness and absorption, distribution, metabolism, and excretion (ADME) analysis were also performed. Based on molecular docking analysis, four of the identified bioactive compounds in G. bicolor, 3-caffeoylquinic acid, 5-O-caffeoylquinic acid, 3,4-dicaffeoylquinic acid, and trans-5-p-coumaroylquinic acid, resulted in lower free-binding energy scores when compared with two of the commercially available gliptin inhibitors. The results revealed that bioactive compounds in G. bicolor are potential natural inhibitors of DPPIV.

Modified human glucagon-like peptide-1 (GLP-1) produced in E. coli has a long-acting therapeutic effect in type 2 diabetic mice

Glucagon-like peptide 1 (GLP-1) is a very potent insulinotropic hormone secreted into the blood stream after eating. Thus, it has potential to be used in therapeutic treatment of diabetes. The half-life of GLP-1, however, is very short due to its rapid cleavage by dipeptidyl peptidase IV (DPP-IV). This presents a great challenge if it is to be used as a therapeutic drug. GLP-1, like many other small peptides, is commonly produced through chemical synthesis, but is limited by cost and product quantity. In order to overcome these problems, a sequence encoding a six codon-optimized tandem repeats of modified GLP-1 was constructed and expressed in the E. coli to produce a protease-resistant protein, 6×mGLP-1. The purified recombinant 6×mGLP-1, with a yield of approximately 20 mg/L, could be digested with trypsin to obtain single peptides. The single mGLP-1 peptides significantly stimulated the proliferation of a mouse pancreatic β cell line, MIN6. The recombinant peptide also greatly improved the oral glucose tolerance test of mice, exerted a positive glucoregulatory effect, and most notably had a glucose lowering effect for as long as 16.7 hours in mice altered to create a type 2 diabetic condition and exerted a positive glucoregulatory effect in db/db mice. These results indicate that recombinant 6×mGLP-1 has great potential to be used as an effective and cost-efficient drug for the treatment of type 2 diabetes.

Gliptins in managing diabetes - Reviewing computational strategy

The pace of anti-diabetic drug discovery is very slow in spite of increasing rate of prevalence of Type 2 Diabetes which remains a major public health concern. Though extensive research steps are taken in the past decade, yet craves for better new treatment strategies to overcome the current scenario. One such general finding is the evolution of gliptins which discriminately inhibits DPP4 (Dipeptidyl peptidase-4) enzyme. Although the mechanism of action of gliptin is highly target oriented and accurate, still its long-term use stands unknown. This step calls for a fast, flexible, and cost-effective strategies to meet the demands of producing arrays of high-content lead compounds with improved efficiency for better clinical success. The present review highlights the available gliptins in the market and also other naturally occurring DPP4 enzyme inhibitors. Along with describing the known inhibitors and their origin in this review, we attempted to identify a probable new lead compounds using advanced computational techniques. In this context, computational methods that integrate the knowledge of proteins and drug responses were utilized in prioritizing targets and designing drugs towards clinical trials with better efficacy. The compounds obtained as a result of virtual screening were compared with the commercially available gliptin in the market to have better efficiency in the identification and validation of the potential DPP4 inhibitors. The combinatorial computational methods used in the present study identified Compound 1: 25022354 as promising inhibitor.

Effect of Glycosin alkaloid from Rhizophora apiculata in non-insulin dependent diabetic rats and its mechanism of action: In vivo and in silico studies

BACKGROUND AND AIM

Diabetes mellitus is a complex multifactorial disorder that remains a great challenging task in the clinical practice. Rhizophora apiculata from Indian medicinal mangrove is widely used to treat inflammation, wound healing and diabetes. Bioassay guided fractionation was followed to isolate Glycosin from the ethanolic extract of R. apiculata. The antidiabetic effect of Glycosin in diabetic rats was investigated and determined their possible mechanism of action.

METHODS

Diabetes was induced in adult Wistar rats by a single intraperitoneal injection of streptozotocin and nicotinamide. Based on the oral glucose tolerance test, Glycosin (50mg/kg b.wt.) was orally administrated to diabetic rats for a period of 45 days. In different intervals, blood glucose and body weight were recorded. After 45 days, blood samples were collected to determine serum lipid profile, level of plasma insulin, hemoglobin, liver, and kidney functions using the appropriate tests. In addition the levels of carbohydrate metabolic enzymes in the liver homogenate were also measured. To determine the molecular mechanism of action, we followed the molecular docking of Glycosin in its possible targets, dipeptidyl peptidase-IV (DPP-IV), Peroxisome proliferator-activated receptor gamma (PPARγ), phosphorylated insulin receptor, and protein tyrosine phosphatase 1B (PTP-1B).

RESULTS

Glycosin treatment significantly (p<0.01) reduced the blood-glucose level, increased the body weight, increase hemoglobin, high-density lipoprotein and insulin level, protein, in addition the activity of hexokinase when compared to untreated rats. Decreased activities of liver function enzymes as well as level of urea, and creatinine were observed in Glycosin treated rats. Docking simulation confirmed that Glycosin interacted with DPP-IV, Insulin receptor and PTP-1B and PPARγ with more affinity and binding energy.

CONCLUSION

Glycosin acts as antihyperglycemic agent, associated with antihyperlipidemic and possibility function as a ligand for proteins that are targets for antidiabetes drugs.

Naturally Occurring Carbazole Alkaloids from Murraya koenigii as Potential Antidiabetic Agents

This study identified koenidine (4) as a metabolically stable antidiabetic compound, when evaluated in a rodent type 2 model (leptin receptor-deficient db/db mice), and showed a considerable reduction in the postprandial blood glucose profile with an improvement in insulin sensitivity. Biological studies were directed from the preliminary in vitro evaluation of the effects of isolated carbazole alkaloids (1-6) on glucose uptake and GLUT4 translocation in L6-GLUT4myc myotubes, followed by an investigation of their activity (2-5) in streptozotocin-induced diabetic rats. The effect of koenidine (4) on GLUT4 translocation was mediated by the AKT-dependent signaling pathway in L6-GLUT4myc myotubes. Moreover, in vivo pharmacokinetic studies of compounds 2 and 4 clearly showed that compound 4 was 2.7 times more bioavailable than compound 2, resulting in a superior in vivo efficacy. Therefore, these studies suggested that koenidine (4) may serve as a promising lead natural scaffold for managing insulin resistance and diabetes.