Current Medicinal Chemistry - Volume 21, Issue 13, 2014

Cu(I)-catalyzed Azide-Alkyne Cycloaddition (CuAAC) is often utilized in medicinal chemistry to make the triazole moiety as it acts as a non-classical bioisostere of the peptide bond. This useful technique can also be applied in the fragment-based assembly of molecular libraries for high-throughput screening. This minireview outlines the application of click-chemistry in the synthesis of enzyme inhibitors with the triazole moiety.

Formyl peptide receptors (FPRs) are G protein-coupled receptors (GPCRs) expressed on a variety of cell types. These receptors play an important role in the regulation of inflammatory reactions and sensing cellular damage. They have also been implicated in the pathogenesis of various diseases, including neurodegenerative diseases, cataract formation, and atherogenesis. Thus, FPR ligands, both agonists and antagonists, may represent novel therapeutics for modulating host defense and innate immunity. A variety of molecules have been identified as receptor subtype-selective and mixed FPR agonists with potential therapeutic value during last decade. This review describes our efforts along with recent advances in the identification, optimization, biological evaluation, and structure–activity relationship (SAR) analysis of small molecule non-peptide FPR agonists and antagonists, including chiral molecules. Questions regarding the interaction at the molecular level of benzimidazoles, pyrazolones, pyridazin-3(2H)-ones, N-phenylureas and other derivatives with FPR1 and FPR2 are discussed. Application of computational models for virtual screening and design of FPR ligands is also considered.

Three decades of extensive research on biological activity of natural tripeptide Gly-His-Lys has established the substructure for development of its novel derivatives which give hope for widening the application in the field of medicine and dermatology. Synthetic approaches to obtain Gly-His-Lys and its modifications provide both classical solution method and solid phase peptide synthesis, usage of different protecting groups and methods of peptide bond formation. In our present review, we emphasize on the methods of the synthesis described in the literature and present the aspects of Gly-His-Lys structure modifications that played a key role in scientific research.

Selegiline (1) [(-)-deprenyl] is used to treat patients with Parkinson’s disease. Nevertheless, in much higher doses it has beneficial effects in depression, and dementia of the aged patients. Selegiline (1) undergoes a complex metabolic pathway. Its major metabolites include (-)-desmethyldeprenyl (2), (-)-methamphetamine (3) and (-)-amphetamine (4), deprenyl-N-oxide (5) and formaldehyde (6) as a small metabolic fragment. In addition, more than 40 minor metabolites of selegiline (1) have also been either detected or proposed by investigators and researchers. This review analyses the pharmacological activity, generation pathway and the detection method of the major metabolites of selegiline (1).

MicroRNA (abbr. miRNA) is an endogenous small non-coding RNAs (containing ~22 nucleotides) found in plants and animals, which functions in transcriptional and post-transcriptional regulation of gene expression. These endogenous gene expression inhibitors were primarily described in cancer but recent emerging roles in the regulation of autoimmune inflammation which is thought to be associated with cardiovascular diseases (CVDs), including atherosclerosis known as an autoimmune disease. MiRNA controls innate and adaptive immune responses to intracellular bacterial infection by targeting interferon-γ, and plays the roles in endothelial cell (EC), vascular smooth muscle cell (VSMC), and macrophages, and thereby leading to regulate the progression of atherosclerosis. MiRNA modulates several pathways such as lipid uptake and Toll-like receptor (TLR) signaling, implicating an involvement in plaque development. In the present review, we focus on the roles of microRNAs in atherosclerosis through which highlight the therapeutic possibility for the treatment of atherosclerosis.

Proteome analysis of body fluids is a powerful tool to identify biomarkers of neurological disorders. Multiple sclerosis (MScl) is a chronic disabling disorder of central nervous system (CNS) and is regarded as an autoimmune disease to myelin components. Clinical subtypes of MScl differ in course, prognosis and response to available therapy. There is evidence of a different pattern of CNS lesions in subtypes, suggesting different immunological mechanisms are relevant in inflammatory demyelination. In order to elucidate proteome signatures, we used two-dimensional differential gel electrophoresis (2D-DIGE) to compare the protein expression profile in serum of different clinical subtypes of MScl patients and of healthy volunteers, resp. controls. Significant expression differences were detected by 2D-DIGE for 241 serum proteins, and transthyretin, zinc-alpha-2-glycoprotein, alpha-1-antitrypsin, immunoglobulin and complement factors (C4, C6 and C8) were identified as potential disease signatures for MScl patients. Three highly-expressed proteins were selected for further evaluation in individual patients by independent immunoassays, and the up-regulation of transthyretin, zinc alpha-2-glycoprotein and immunoglobulin kappa light chain was validated in sera of relapsing-remitting (CIS and RRMScl) patients, when compared to healthy donors. To present significant expression differences in PPMScl, analysis with a larger patient population is required.

Cyclic 3-hydroxymelatonin (C3HOM) is an immediate product of melatonin’s interaction with reactive oxygen species. Its presence has been detected in mice, rats and humans. In the current study, the antioxidant capacity and reducing power of this molecule have been systematically studied. C3HOM is found to be a more potent antioxidant than melatonin or vitamin C in terms of its ability to scavenge the hydroxyl radical (HO.) and to recover oxidized horseradish peroxidase to its ground state. The antioxidative mechanism of C3HOM is similar to that of the classic antioxidant, vitamin C, rather than to its precursor melatonin. C3HOM effectively prevents the oxidative degradation of cytochrome C induced by hydrogen peroxide (H2O2). It is speculated that some antioxidative activities of melatonin may be mediated by its metabolite, C3HOM. C3HOM prevents mitochondrial cytochrome C injury and, thus, it is likely to inhibit cellular apoptosis induced by the release of oxidized cytochrome C from mitochondria.