Therapeutic potential and recent progression of BTK inhibitors against rheumatoid arthritis.

Rheumatoid arthritis (RA) is a complex chronic inflammatory illness that affects the entire physiology of human body. It has become one of the top causes of disability worldwide. The development and progression of RA involves a complex interplay between an individual's genetic background and various environmental factors. In order to effectively manage RA, a multidisciplinary approach is required, as this disease is complicated and its pathophysiological mechanism is not fully understood yet. In majority of arthritis patients, the presence of abnormal B cells and autoantibodies, primarily anti-citrullinated peptide antibodies and rheumatoid factor affects the progression of RA. Therefore, drugs targeting B cells have now become a hot topic in the treatment of RA which is quite evident from the recent trends seen in the discovery of various B cell receptors (BCRs) targeting agents. Bruton's tyrosine kinase (BTK) is one of these recent targets which play a role in the upstream phase of BCR signalling. BTK is an important enzyme that regulates the survival, proliferation, activation and differentiation of B-lineage cells by preventing BCR activation, FC-receptor signalling and osteoclast development. Several BTK inhibitors have been found to be effective against RA during the in vitro and in vivo studies conducted using diverse animal models. This review focuses on BTK inhibition mechanism and its possible impact on immune-mediated disease, along with the types of RA currently being investigated, preclinical and clinical studies and future prospective.

Molecular Docking and In Vitro Anticancer Screening of Synthesized Arylthiazole linked 2H-indol-2-one Derivatives as VEGFR-2 Kinase Inhibitors.

BACKGROUND: Indoline-2,3-dione comprises a leading course group of heterocycles endowed with appealing biological actions, including anticancer activity. There are significant justifications for exploring the anticancer activity of Schiff base derivatives of isatin as a vast number of reports have documented remarkable antiproliferative action of isatin nucleus against various cancer cell lines. AIMS AND OBJECTIVES: A series of arylthiazole linked 2H-indol-2-one derivatives (5a-t) was designed and synthesized as potential VEGFR-2 kinase inhibitors keeping the essential pharmacophoric features of standard drugs, like sunitinib, sorafenib, nintedanib, etc. They were evaluated for their in vitro anticancer activity. The aim of this study was to investigate and assess the anticancer potential of isatin-containing compounds along with their kinase inhibition activity. METHODS: The title compounds were synthesized by reacting substituted isatins with para-substituted arylthiazoles using appropriate reaction conditions. Selected synthesized derivatives went under preliminary screening against a panel of 60 cancer cell lines at NCI, the USA, for single-dose and five dose assays. Molecular docking was performed to explore the binding and interactions with the active sites of the VEGFR-2 receptor (PDB Id: 3VHE). Derivatives 5a, 5b, 5c, 5d, 5g, 5h, and 5m were assessed for in vitro inhibition potency against Human VEGFR-2 using ELISA (Enzyme- Linked Immunosorbent Assay) kit. All the target compounds were determined against human colon cancer cell line SW480 (colorectal adenocarcinoma cells). Cellular apoptosis/necrosis was determined by flow cytometry using annexin V-FITC. DNA content of the cells was analyzed by flow cytometry and the cycle distribution was quantified. RESULTS: Compounds 5a and 5g exhibited noteworthy inhibition during a five-dose assay against a panel of 60 cell lines with MID GI50 values of 1.69 and 1.54 µM, respectively. Also, both the lead compounds 5a and 5g demonstrated promising VEGFR-2 inhibitory activity with IC50 values of 5.43±0.95 and 9.63±1.32 µM, respectively. The aforesaid potent compounds were found effective against SW480 (colorectal adenocarcinoma cells) with IC50 values of 31.44 µM and 106.91 µM, respectively. Compound 5a was found to arrest the cell cycle at the G2/M phase, increasing apoptotic cell death. The docking study also supported VEGFR-2 inhibitory activity as both compounds 5a and 5g displayed promising binding and interactions with the active sites of VEGFR-2 receptor (PDB: 3VHE) with docking scores - 9.355 and -7.758, respectively. All the compounds obeyed Lipinski's rule of five. CONCLUSION: Indoline-2,3-dione and thiazole have huge potential to be considered a steer combination approach for developing promising kinase inhibitors as cancer therapeutics.

Development of Thiazole-5-carboxylate Derivatives as Selective Inhibitors of Monoacylglycerol Lipase as Target in Cancer.

INTRODUCTION: The signalling function of 2-arachidonoylglycerol (2-AG) in endocannabinoid system is delineated by Monoacylglycerol lipase (MAGL). MAGL readdresses the lipid stores in the direction of pro-tumorigenic signalling lipids in cancer cells. Selective as well as potent MAGL inhibitors are limited in number hence their continuous development may lead to a breakthrough invention in the field of MAGL inhibitors. In succession of the above, we have synthesised 2-amino-4- methylthiazole-5-carboxylate derivatives and characterised them by collective use of IR, 1H-NMR, 13C-NMR, Mass spectral data and elemental analysis. METHODOLOGY: Thirteen compounds (3c-g, 4c, 4e, 4f and 6b-f) inhibited MAGL with IC50 value 0.037- 9.60 µM. Two compounds (3g and 4c) were found to be most potent with IC50 values 0.037 and 0.063µM, respectively. Thirty synthesised compounds were sent to NCI for anticancer screening, out of which nine compounds were selected for one dose anticancer assay. Compounds 3g (NSC:788170) and 4c (NSC:788176)were found to be the most potent during one dose anticancer screening and fulfilled the specified threshold for growth inhibition criteria of NCI and were further selected for full panel five dose assay at 10-fold dilutions of five different concentrations. CONCLUSION: Compound 3g displayed GI50 value 0.865 µM against EKVX (Non-Small Cell Lung Cancer cell line), and 1.20 µM against MDA-MB-468 (Breast Cancer cell Line), while (4c) showed GI50 value 0.34 and 0.96 µM against HOP-92 and EKVX (Non-Small Cell Lung Cancer cell line) and 1.08 µM against MDA-MB-231/ATCC(Breast Cancer cell Line). In addition, molecular docking studies of the said MAGL inhibitors have also been presented in this article.

Imidazole: An Essential Edifice for the Identification of New Lead Compounds and Drug Development.

In recent years, a drastic rise has been observed in incidences of resistance, low efficacy rates and toxicities to various drugs used in therapeutic application. Presence of imidazole nucleus in several categories of therapeutic agents such as anti-microbials, anti-virals, anti-cancer, etc has made it a vital anchor for the development of new therapeutic agents. Still, there is a need to couple the newest information with the already available knowledge to recognize the present standing of imidazole motif in medicinal chemistry research. In the present review, importance of this nucleus in some less explored activities like anti-malarial and anthelmintic is mentioned along with well explored fields like cancer. Substitution pattern around imidazole nucleus is discussed here with an aim to help medicinal chemists for the development of SAR of imidazole based compounds for each activity. This discussion will further help in the advancement of existing imidazole derivatives and in the generation of new and safe imidazole compounds.

2-Benzamido-4-methylthiazole-5-carboxylic Acid Derivatives as Potential Xanthine Oxidase Inhibitors and Free Radical Scavengers.

The new chemical entities febuxostat and topiroxostat have been approved by the US Food and Drug Administration, opening new avenues for exploiting different heterocycles other than purines as xanthine oxidase (XO) inhibitors. A different series of substituted 2-benzamido-4-methylthiazole-5-carboxylic acid derivatives (5a-r) was synthesized and characterized by the collective use of IR, 1 H and 13 C NMR, and mass spectroscopy, for the treatment of gout and hyperuricemia. In vitro studies of the synthesized derivatives revealed that the presence of a fluoro group at the para position in 5b (IC50 = 0.57 µm) and a chloro group in 5c (IC50 = 0.91 µm) signifies excellent XO inhibitory activity among the series, along with their DPPH free radial scavenging activity. In vivo serum uric acid inhibition studies established that 5b and 5c displayed 62 and 53% uric acid inhibition, respectively. Studies on enzyme kinetics indicated that 5b acts as a mixed type inhibitor. In silico prediction by various softwares also helped in the recognition of potent XO inhibitors.

Development of 2-(Substituted Benzylamino)-4-Methyl-1, 3-Thiazole-5-Carboxylic Acid Derivatives as Xanthine Oxidase Inhibitors and Free Radical Scavengers.

A series of 2-(substituted benzylamino)-4-methylthiazole-5-carboxylic acid was designed and synthesized as structural analogue of febuxostat. A methylene amine spacer was incorporated between the phenyl ring and thiazole ring in contrast to febuxostat in which the phenyl ring was directly linked with the thiazole moiety. The purpose of incorporating methylene amine was to provide a heteroatom which is expected to favour hydrogen bonding within the active site residues of the enzyme xanthine oxidase. The structure of all the compounds was established by the combined use of FT-IR, NMR and MS spectral data. All the compounds were screened in vitro for their ability to inhibit the enzyme xanthine oxidase as per the reported procedure along with DPPH free radical scavenging assay. Compounds 5j, 5k and 5l demonstrated satisfactory potent xanthine oxidase inhibitory activities with IC50 values, 3.6, 8.1 and 9.9 µm, respectively, whereas compounds 5k, 5n and 5p demonstrated moderate antioxidant activities having IC50 15.3, 17.6 and 19.6 µm, respectively, along with xanthine oxidase inhibitory activity. Compound 5k showed moderate xanthine oxidase inhibitory activity as compared with febuxostat along with antioxidant activity. All the compounds were also studied for their binding affinity in active site of enzyme (PDB ID-1N5X).