Mini Reviews in Medicinal Chemistry - Volume 12, Issue 2, 2012

Balaglitazone (DRF-2593) is a novel partial agonist of PPAR-gamma (γ), which is developed by Dr. Reddy's laboratories India. Balaglitazone is a second generation peroxisome proliferator-activated receptor (PPAR) gamma agonist with only partial agonistic properties. Balaglitazone is currently being evaluated in phase III clinical trial in United States and Europe. Selective PPAR-γ modulators bind in distinct manners to the ligand-binding pocket of PPAR-γ, leading to alternative receptor conformations, differential cofactor recruitment/displacement, differential gene expression, and ultimately differential biological responses. Based on this concept, new and improved novel antidiabetic agents are in current development. Clinical studies conducted with 409 subjects of randomized, double blind, parallel-group placeboand active comparator-controlled subject groups to determine the efficacy and safety of Balaglitazone. The study showed that the trial met its primary endpoint. Balaglitazone treated groups shown significantly reduce of HbA1c (%), FSG (mmol/L), postprandial glucose as comparison to pioglitazone. Phase III clinical studies data clearly shows that Balaglitazone provides robust glycemic control as an add-on to insulin therapy. Balaglitazone 10mg and 20mg show the similar magnitudes of the effects which comparable to the effects seen in the pioglitazone 45mg group. The incidence of fluid retention and fat accumulation fewer than those observed with pioglitazone 45mg. Hence, Balaglitazone is prominent candidate of new glitazone which requires fewer doses as comparison pioglitazone and shows better safety profile less incidence of special adverse effect like heart failure, peripheral oedema, and myocardial infarction. Unlike other marketed PPAR gamma agonists, Balaglitazone shows less fluid retention, less heart enlargement and no reduction of bone formation than full PPAR gamma agonists in preclinical studies. In present review, we have tried to cover classification PPARs various ligands, chemistry, physical properties, commercial synthesis, current patent status, polymorphic information, receptor interaction, pharmacophore rational, mechanism, adverse effect and clinical status of Balaglitazone, giving emphasis on medicinal chemistry aspect.

Kinases are probably the most important signaling enzymes, which represent about 20% of the druggable genome. Currently, more than 150 kinases are known. So, kinase inhibition therapy has become a very important area of drug research since most of our diseases are related to intra or intercellular signaling by kinases. Indole alkaloids are extensively studied for their biological activities in several pharmaceutical areas, including, for example, antitumor. Among this chemical family, indolinone displays very promising antitumor properties by inhibiting various kinase families. These small molecules have a low molecular weight and most of them bind to protein kinases competing with ATP for the ATP-binding site. This review focuses on the indolinone based drugs approved for the treatment of cancer, drugs under clinical trial and then chemical diversity of various synthetic analogues of indolinone and their metabolites as various kinase inhibitors. This review also focused on structural activity relationship (SAR), mechanisms of action and biological targets through which indolinone and its derivatives display their antitumor activity.

The biological activities and mechanisms of tea polyphenols and their polymerics have been attractive issues in cancer research. The inhibition of tea polyphenols on cancer cells decreased cell proliferation and increased apoptosis. Tremendous evidences have shown that tea polyphenols suppress tumor promotion by inhibiting enzyme activities and blocking signal transduction pathways. Specifically, the mitogen activated protein kinases (MAPK) pathways have been implicated as an important target molecular for cancer prevention and therapy. The purpose of this review is to discuss the relationship between tea polyphenols and MAPK signaling pathways in cancer.

The genus Chaetomium fungi are considered to be a rich source of novel and bioactive secondary metabolites of great importance. Up till now, a variety of more than 200 secondary metabolites belonging to diverse structural types of chaetoglobosins, epipolythiodioxopiperazines, azaphilones, xanthones, anthraquinones, chromones, depsidones, terpenoids, and steroids have been discovered. Most of these fungal metabolites exhibited antitumor, cytotoxic, antimalarial, enzyme inhibitory, antibiotic, and other activities. This review covers the extraction, structure elucidation, structural diversity, and biological activities of natural products isolated from about 30 fungi associated with marine- and terrestrial- origins, and highlights some bioactive compounds as well as their mechanisms of action and structure-activity relationships.

Phytoestrogens are estrogenic compounds of plant origin classified into different groups including isoflavones, lignans, coumestans and stilbenes. Isoflavones such as genistein and daidzein are the most studied and most potent phytoestrogens, and are found mainly in soy based foods. The effects of phytoestrogens are partly mediated via estrogen receptors (ERs): ERα, ERβ and possibly GPER. The interaction of phytoestrogens with ERs is thought to induce both genomic and non-genomic effects in many tissues including the vasculature. Some phytoestrogens such as genistein have additional non-ER-mediated effects involving signaling pathways such as tyrosine kinase. Experimental studies have shown beneficial effects of phytoestrogens on endothelial cells, vascular smooth muscle, and extracellular matrix. Phytoestrogens may also affect other pathophysiologic vascular processes such as lipid profile, angiogenesis, inflammation, tissue damage by reactive oxygen species, and these effects could delay the progression of atherosclerosis. As recent clinical trials showed no vascular benefits or even increased risk of cardiovascular disease (CVD) and CV events with conventional menopausal hormone therapy (MHT), phytoestrogens are being considered as alternatives to pharmacologic MHT. Epidemiological studies in the Far East population suggest that dietary intake of phytoestrogens may contribute to the decreased incidence of postmenopausal CVD and thromboembolic events. Also, the WHOCARDIAC study supported that consumption of high soybean diet is associated with lower mortalities from coronary artery disease. However, as with estrogen, there has been some discrepancy between the experimental studies demonstrating the vascular benefits of phytoestrogens and the data from clinical trials. This is likely because the phytoestrogens clinical trials have been limited in many aspects including the number of participants enrolled, the clinical end points investigated, and the lack of long-term follow-up. Further investigation of the cellular mechanisms underlying the vascular effects of phytoestrogens and careful evaluation of the epidemiological evidence and clinical trials of their potential vascular benefits would put forward the use of phytoestrogens as an alternative MHT for the relief of menopausal symptoms and amelioration of postmenopausal CVD.

Cell adhesion molecules (CAMs) are transmembrane proteins that mediate adhesion and interactions between cells or cell and extra-cellular matrix. Increased expression and activation of CAMs in vascular endothelial cells and circulating leukocytes, as occurring in the settings of inflammation, hypercholesterolemia, hypertension and diabetes, stimulates leukocyte recruitment into the vascular endothelium, an important step in the pathogenesis of atherosclerosis. CAMs are a potential therapeutic target in clinical practice and in recent years pharmaceutical agents with specific effects on the production and function of these molecules have been studied and developed. This article reviews recent progress regarding pathophysiology of CAMs in atherogenesis and pharmaceutical products or chemicals that are active against CAMs, and assesses the possibilities for clinical developments in this area that might enhance the prevention, monitoring and treatment of atherosclerotic cardiovascular diseases.