1,3,4-Oxadiazole Scaffold in Antidiabetic Drug Discovery: An Overview.

Diabetes mellitus is one of the biggest challenges for the scientific community in the 21st century. With the increasing number of cases of diabetes and drug-resistant diabetes, there is an urgent need to develop new potent molecules capable of combating this cruel disease. Medicinal chemistry concerns the discovery, development, identification, and interpretation of the mode of action of biologically active compounds at the molecular level. Oxadiazole-based derivatives have come up as a potential option for antidiabetic drug research. Oxadiazole is a five-membered heterocyclic organic compound containing two nitrogen atoms and one oxygen atom in its ring. Oxadiazole hybrids have shown the ability to improve glucose tolerance, enhance insulin sensitivity, and reduce fasting blood glucose levels. The mechanisms underlying the antidiabetic effects of oxadiazole involve the modulation of molecular targets such as peroxisome proliferator-activated receptor gamma (PPARγ), α-glucosidase, α-amylase and GSK-3ß which regulate glucose metabolism and insulin secretion. The present review article describes the chemical structure and properties of oxadiazoles and highlights the antidiabetic activity through action on different targets. The SAR for the oxadiazole hybrids has been discussed in this article, which will pave the way for the design and development of new 1,3,4-oxadiazole derivatives as promising antidiabetic agents in the future. We expect that this article will provide comprehensive knowledge and current innovation on oxadiazole derivatives with antidiabetic potential and will fulfil the needs of the scientific community in designing and developing efficacious antidiabetic agents.

An Insight into the Combat Strategies for the Treatment of Type 2 Diabetes Mellitus.

Diabetes is a chronic, and metabolic disorder that has gained epidemic proportions in the past few decades creating a threat throughout the globe. It is characterized by increased glucose levels that may be due to immune-mediated disorders (T1DM), insulin resistance or inability to produce sufficient insulin by ß-pancreatic cells (T2DM), gestational, or an increasingly sedentary lifestyle. The progression of the disease is marked by several pathological changes in the body like nephropathy, retinopathy, and various cardiovascular complications. Treatment options for T1DM are majorly focused on insulin replacement therapy. While T2DM is generally treated through oral hypoglycemics that include metformin, sulfonylureas, thiazolidinediones, meglitinides, incretins, SGLT-2 inhibitors, and amylin antagonists. Multidrug therapy is often recommended when patients are found incompliant with the first-line therapy. Despite the considerable therapeutic benefits of these oral hypoglycemics, there lie greater side effects (weight variation, upset stomach, skin rashes, and risk of hepatic disease), and limitations including short half-life, frequent dosing, and differential bioavailability which inspires the researchers to pursue novel drug targets and small molecules having promising clinical efficacy posing minimum side-effects. This review summarizes some of the current emerging novel approaches along with the conventional drug targets to treat type 2 diabetes.

A comprehensive review on the antidiabetic attributes of thiazolidine-4-ones: Synthetic strategies and structure-activity relationships.

The thiazolidine-4-one scaffold has recently emerged as a potential pharmacophore having clinical significance for medicinal chemists. This heterocyclic ring has been reported to possess a plethora of biological activities, including antidiabetic activity that has inspired researchers to integrate this core with different pharmacophoric fragments to design novel and effective antidiabetic leads. The antidiabetic activity has been observed due to the ability of the thiazolidine-4-one nucleus to interact with different biological targets, including peroxisome proliferator-activated receptor γ, protein tyrosine phosphatase 1B, aldose reductase, α-glucosidase, and α-amylase. The present review discusses the mode of action of thiazolidine-4-ones through these antidiabetic drug targets. This review attempts to summarize and analyze the recent developments with regard to the antidiabetic potential of thiazolidine-4-ones covering different synthetic strategies, structure-activity relationships, and docking studies reported in the literature. The significance of various structural modifications at C-2, N-3, and C-5 of the thiazolidine-4-one ring has also been discussed in this manuscript. This comprehensive compilation will provide an inevitable scope for the design and development of potential antidiabetic drug candidates having a thiazolidine-4-one core.

A complete review of empagliflozin: Most specific and potent SGLT2 inhibitor used for the treatment of type 2 diabetes mellitus.

Sodium-glucose co-transporter 2 (SGLT2) inhibitors are the latest class of drugs to be introduced for the treatment of type 2 diabetes mellitus (T2DM). They reduce hyperglycemia by increasing urinary glucose excretion and exert favorable effects beyond glucose control with consistent body weight, blood pressure, and serum uric acid reductions. Empagliflozin is a potent SGLT2 inhibitor used to improve glycemic control in adults with T2DM. It has the highest SGLT2 specificity among all the clinically used or currently tested SGLT2 inhibitors. Low risk of hypoglycemia, absence of weight gain and demonstrated cardiovascular risk reduction support its consideration as a first line medication in addition to metformin for patients with T2DM and cardiovascular disease. Mostly reported adverse events are genital mycotic infections, while urinary tract infections and events linked to volume depletion are rather rare. This review covers the complete information on empagliflozin including the history of its development, synthesis, pharmacology and different methods which have been reported for its analysis.

1,2,4-Oxadiazole as a Privileged Scaffold for Anti-inflammatory and Analgesic Activities: A Review.

1,2,4-Oxadiazole is one of the important heterocycles used by medicinal chemists in designing a new therapeutic molecule. The compounds containing this nucleus are reported to have a wide range of pharmaceutical and biological applications including anti-inflammatory and analgesic activities. The fused and pendent 1,2,4-oxadiazole moiety has been traced in a number of well established, commercially available drugs. This review article provides an up to date information about techniques adopted for the synthesis of 1,2,4-oxadiazoles, and their therapeutic importance as anti-inflammatory and analgesic agents.

Exploring 1,3,4-Oxadiazole Scaffold for Anti-inflammatory and Analgesic Activities: A Review of Literature From 2005-2016.

1,3,4-Oxadiazole derivatives are found to have a wide range of pharmacological activities and attracting the researchers to work on this nucleus. Literature survey indicates that many 1,3,4- oxadiazoles have been synthesized with the aim to get compounds of significant anti-inflammatory and analgesic activities with reduced adverse effects. The purpose of this review is to compile the reports on 1,3,4-oxadiazole derivatives possessing anti-inflammatory and analgesic activities. The review also includes the reports on 1,3,4-oxadiazole derivatives of existing NSAIDs in the last ten years.

Chemical Modifications of Ketoprofen (NSAID) in Search of Better Lead Compounds: A Review of Literature From 2004-2016.

BACKGROUND: Ketoprofen, a potent anti-inflammatory, analgesic and anti-pyretic drug belonging to the propionic acid class was synthesized in 1968. Rapid absorption, simple metabolism, faster blood brain barrier crossing and high antinociceptive activity are the features responsible for its high use. But, free acidic moiety present in its structure is the major factor that declines its popularity by causing various gastric side effects. Many researchers have chemically modified this drug with the aim to discover an improved and safe NSAID candidate or a new drug with altered activity. We thoroughly searched the literature and found that during the period 2004-2016, more than fifty reports are available on chemical modification of ketoprofen. Along with this, many patents involving chemical modification of ketoprofen have also been reported. However, it was very surprising to note that there are only a few review articles available covering only its pharmacological and clinical properties. There is no review article available covering the chemistry part of ketoprofen. This motivated us to compile the information available on ketoprofen and its derivatives. The purpose of this article is to present an updated review about this topic. METHODS: We thoroughly searched the peer reviewed research literature and compiled all such reportings (2004 onwards) for the benefit of researchers who further want to work on ketoprofen or other NSAIDs. RESULTS: Studies have been conducted to invent strategies to reduce the ulcerogenic properties of ketoprofen and in the course of time, its modified and improved derivatives have been synthesized in search of safer NSAIDs. Along with the aim of reducing the gastric side-effects, researchers have also done chemical modifications in the structure of ketoprofen to improve its solubility, to alter its blood brain-barrierr permeability, to improve its pharmacodynamic profile and to get derivatives possessing antioxidant, antiviral, anticancer and immunomodulatory activities. CONCLUSION: The findings of the review confirm that chemical modifications of ketoprofen decrease ulcer producing side effect while maintaining its desirable actions. Some derivatives were also found to possess better activity profile compared to the parent drug.

Synthesis and pharmacological evaluation of pyrazolo[4,3-c]cinnoline derivatives as potential anti-inflammatory and antibacterial agents.

A series of pyrazolo[4,3-c]cinnoline derivatives was synthesized, characterized and evaluated for anti-inflammatory and antibacterial activity. Test compounds that exhibited good anti-inflammatory activity were further screened for their ulcerogenic and lipid peroxidation activity. Compounds 4d and 4l showed promising anti-inflammatory activity with reduced ulcerogenic and lipid peroxidation activity when compared to naproxen. Docking results of these two compounds with COX-2 (PDB ID: 1CX2) also exhibited a strong binding profile. Among the test derivatives, compound 4i displayed significant antibacterial property against gram-negative (Escherichia coli and Pseudomonas aeruginosa) and gram-positive (Staphylococcus aureus) bacteria. However, compound 4b emerged as the best dual anti-inflammatory-antibacterial agent in the present study.

Synthesis and antimicrobial screening of N-[2-(2/4-substituted phenyl)-1-(5/6 substituted 1H- benzimidazol-2-yl)vinyl]benzamides.

A series of (benzamidostyryl)benzimidazole derivatives were synthesized by hydrolyzing 2-phenyl-4-(substituted)benzylidene-5-oxazolones, the azlactone precursors in an acidic medium and treating the product with substituted o-phenylenediamine (OPDA) in situ. The structures of the synthesized compounds were confirmed by spectral and elemental analyses. All synthesized compounds were screened for their in vito antimicrobial activities against some identifiable strains. Thereby, it was found that only nitro substituted benzimidazoles exhibited good to moderate antibacterial activity, while other derivatives were devoid of any antimicrobial effect.

Syntheses and evaluation of anti-inflammatory, analgesic and ulcerogenic activities of 1,3,4-oxadiazole and 1,2,4-triazolo[3,4-b]-1,3,4-thiadiazole derivatives.

Several 2,5-disubstituted-1,3,4-oxadiazoles (4a-f) and 3,6-disubstituted-1,2,4-triazolo[3,4-b]-1,3,4-thiadiazoles (7a-f) were synthesized and characterized by elemental analyses and spectral data. These compounds were screened for their anti-inflammatory, analgesic, ulcerogenic and lipid peroxidation activities. Compound 7c showed excellent anti-inflammatory and remarkable analgesic activity with reduced ulcerogenic and lipid peroxidation activity when compared with ibuprofen.

N'-[(5-chloro-3-methyl-1-phenyl-1H-pyrazol-4-yl)methylene] 2/4-substituted hydrazides: synthesis and anticonvulsant activity.

A series of N'-[(5-chloro-3-methyl-1-phenyl-1H-pyrazol-4-yl)methylene] 2/4-substituted hydrazides were synthesized using appropriate synthetic route and characterized by elemental analysis and spectral data. The anticonvulsant activity of some of the synthesized compounds were evaluated against maximal electroshock induced seizure (MES) and subcutaneous pentylenetetrazol (scPTZ) induced seizure models in mice. The neurotoxicity were assessed using the rotorod method. All the test compounds were administered at doses of 30, 100, and 300 mg/kg body weight and the anticonvulsant activity was noted at 0.5 and 4 h time intervals after the drug administration. Among the compound tested, all except 5 g showed protection from seizures in both the animal models. Some titled compounds exhibited lesser CNS depression and neurotoxicity compared to phenytoin.

Design & synthesis of 2-(substituted aryloxy)-5-(substituted benzylidene)-3-phenyl-2,5-dihydro-1H-[1,2,4] triazin-6-one as potential anticonvulsant agents.

A series of 2-(substituted aryloxy)-5-(substituted benzylidene)-3-phenyl-2,5-dihydro-1H-[1,2,4] triazin-6-one were designed & synthesized using appropriate synthetic route keeping in view the structural requirement of pharmacophore and evaluated for anticonvulsant activity and CNS activities. After intraperitoneal injection to mice, some synthesized derivatives were examined in the maximal electroshock seizure (MES) and subcutaneous pentylenetetrazol (scPTZ) induced seizure and neurotoxicity screens. Those found potent were also evaluated for behavioural impairment and depression activity. Among the compound tested, 5 eIX showed protection from seizures in both the animal models at dose level of 30 mg/kg while 5 bII &5 cII showed protection against scPTZ model at same dose level. Some titled compounds exhibited lesser CNS depression and neurotoxicity compared to clinically effective drug.