Mini Reviews in Medicinal Chemistry - Volume 14, Issue 2, 2014

This paper addresses the mechanisms behind selective endothelial permeability and their regulations. The singular properties of each of the seven blood-tissues barriers. Then, it further revisits the physical, quantitative meaning of permeability, and the way it should be measured based on sound physical chemistry reasoning and methodologies. Despite the relevance of permeability studies one often comes across inaccurate determinations, mostly from oversimplified data analyses. To worsen matters, the exact meaning of permeability is being lost along with this loss of accuracy. The importance of proper permeability calculation is illustrated with a family of derivatives of kyotorphin, an analgesic dipeptide.

Since the discovery of the first penicillin bacterial resistance to β-lactam antibiotics has spread and evolved promoting new resistances to pathogens. The most common mechanism of resistance is the production of β-lactamases that have spread thorough nature and evolve to complex phenotypes like CMT type enzymes. New antibiotics have been introduced in clinical practice, and therefore it becomes necessary a concise summary about their molecular targets, specific use and other properties. β-lactamases are still a major medical concern and they have been extensively studied and described in the scientific literature. Several authors agree that Glu166 should be the general base and Ser70 should perform the nucleophilic attack to the carbon of the carbonyl group of the β-lactam ring. Nevertheless there still is controversy on their catalytic mechanism. TEMs evolve at incredible pace presenting more complex phenotypes due to their tolerance to mutations. These mutations lead to an increasing need of novel, stronger and more specific and stable antibiotics. The present review summarizes key structural, molecular and functional aspects of ESBL, IRT and CMT TEM β-lactamases properties and up to date diagrams of the TEM variants with defined phenotype. The activity and structural characteristics of several available TEMs in the NCBI-PDB are presented, as well as the relation of the various mutated residues and their specific properties and some previously proposed catalytic mechanisms.

With the emergence of resistance to artemesinin, the need for new antimalarial compounds is pressing. Several research groups have made significant contributions to the exploration of the use of 1,2,4,5-tetraoxanes and 1,2,4- trioxanes as synthetic analogues of artemesinin. This short review highlights the recent developments in this field detailing both biological results and useful synthetic methodology. In addition, the current understanding of the mode of action of this class of compounds has been described.

This review provides a brief summary of thiadiazole ring containing compounds as antidiabetic agents. It covers the most active thiadiazole derivatives selected from reported literature of thiadiazole system as antidiabetic drug substance in the form of synthesis and structural activity relationship study reports. Some of the promising thiadiazole compounds interacting with targets such as sodium-glucose linked transporter, peroxisome proliferator-activated receptor, protein tyrosine phosphatase, c-Jun N-terminal kinase, dipeptidyl peptidase-4 and cannabinoid-1 receptor have been collected with their biological potency. The information provided in this review acts as important overview for medicinal chemist to develop a new chemical entity possessing antidiabetic activity.

Hydrogels are the biomaterials comprising network of natural or synthetic polymers capable of absorbing large amount of water. Hydrogels are “Smart Gels” or “Intelligent Gels” which can be made to respond to the various environmental conditions like temperature, pH, magnetic/electric field, ionic strength, inflammation, external stress etc. There are numerous potential applications of hydrogels in modern day life ranging from a diaper to gene delivery. This review succinctly describes the classification, properties and preparation methods along with numerous diverse applications of hydrogels like agricultural hydrogels, hydrogel for drug delivery, sensing, dental adhesives, wound healing and tissue regeneration, diet aid and gastric retention and in tissue engineering etc. Hydrogels can be regarded as highly valuable biomaterials for human-beings.

1,2,4-Triazine nucleus is a prominent structural core system present in numerous pharmacologically active compounds. Till date, various 1,2,4-triazine analogs, possesing a wide range of potent pharmacological activities, have been reported. This review is an attempt to compile the medicinal chemistry aspects of various synthesized 1,2,4-triazine analogs reported so far.

Glibenclamide (5-chloro-N-(4-[N-(cyclohexylcarbamoyl) sulfamoyl] phenethyl)-2-methoxybenzamide, Glyburide, E) is a well-known and potent second-generation of sulfonylurea oral hypoglycemic drug which is most widely used in type 2 diabetes recently. It acts upon pancreatic β-cells by stimulating insulin secretion in glucose and lipid-lowering activities. So far, many derivatives of E have been synthesized by adding new structural moieties to its structure while preserving its binding affinity to the receptor before their anti-hyperglycemic and anti hyperlipidemic activities being evaluated. In this study, new analogues of E after changing lipophilic side chain (5-chloro-2-methoxy benzamide) with 4- bromo-3, 5-dimethoxy benzamide and 2, 4-dichloro benzamide were synthesized. Also, their glucose and lipid-lowering activities were evaluated and compared to E and Tolbutamide (a famous first-generation of sulfonylurea oral hypoglycemic drug) by the known procedures. Findings showed that chloride substitution on lipophilic side chain of Glibenclamide could possibly increase the affinity of drug for receptor/or its half life time that resulted in more lasting anti-hyperglycemic and anti lipidemic activities in diabetic rats. However, bromide substitution with additional methoxy groups in benzamide ring could slightly improve the anti-hyperglycemic potency of the new drug compared to the root drug (E).