Design, synthesis, and biological evaluation of isatin-indole-3-carboxaldehyde hybrids as a new class of xanthine oxidase inhibitors.

A novel series of triazole-linked isatin-indole-3-carboxaldehyde hybrids based on the febuxostat skeleton and its binding site interactions were rationally designed and synthesized as potential xanthine oxidase inhibitors. Among the synthesized hybrids, A19 showed the most potent xanthine oxidase inhibition (IC50 = 0.37 µM) with the mixed-type inhibitory scenario. Structure-activity relationship studies revealed that methoxy (OCH3 ) substitution on position 5 of the isatin nucleus and a two-carbon distance between isatin and the triazole moiety is most tolerable for the inhibitory potential. Various binding interactions of A19 with the binding site of xanthine oxidase are also streamlined by molecular docking studies, which showcase the favorable binding pattern for xanthine oxidase inhibition by the hybrid. Furthermore, molecular dynamic studies were performed that suggest the stability of the enzyme-hybrid complex. Overall, the study suggests that hybrid A19 can act as an effective hit lead for further development of potent xanthine oxidase inhibitors.

Purine Analogues as Kinase Inhibitors: A Review.

Protein kinases constitute one of the largest and most functionally diverse gene families that regulate key cell functions. In past several years, kinase inhibition has emerged as potential anti-cancer drug target. Purine is a priveleged heterocyclic nucleus which exists in the chemical architecture of various bioactive compounds. Numerous reports on the use of purine analogues in the treatment of acute leukemias (thiopurines, pentostatin), as antiviral (acyclovir, penciclovir, ganciclovir), as immunosuppressive (azathioprine), as antitumor (vidarabine), as bronchodilator (theophylline) have been revealed. In the past decade, purine analogues have emerged as significantly potent kinase inhibitors. A fair amount of research has been done and several patents have also been published highlighting the kinase inhibitory action of purines. Caffeine, 2-aminopurine, purvalanol-A, seleciclib, FSBA, adenosine thiol analogue possessing purine as the basic moiety fall under this category. In view of the use of purines for the inhibition of kinases, there is need for compilation of data specifying the prominence of purines in the treatment of cancer through this mechanism. The structure of the potent compounds, their IC50 values, models used and the enzymes/ receptors/ targets involved have been presented in this review. The present compilation covers the patents published entailing the purines as kinase inhibitors and the purine drugs employed in chemotherapy.

Anti-cancer pyrimidines in diverse scaffolds: a review of patent literature.

Pyrimidine ring is the building unit of DNA and RNA and thus pyrimidine based chemical architectures exhibit diverse pharmacological activities. Among the reported medicinal attributes of pyrimidines, anticancer activity is the most extensively reported. The anticancer potential of pyrimidines in fused scaffolds has also been evidenced through number of research article and patent literature. The pyrimidines based scaffolds have exerted their cell killing effects through varied mechanisms which indicate their potential to interact with diverse enzymes/ targets/receptors. This review article strictly focuses on the patent literature from 2009 onwards. The structure of the potent compounds, their IC50 values, models/assays used for the anticancer evaluation and the enzymes/ receptors/ targets involved have been presented in this compilation. Significant number of patents i.e. 59 have been published on pyrimidine based anticancer agents from 2009-2014 (from 2009 through the present date) which clearly indicate that this heterocycle is an area of focus at present for researchers all over the globe. Moreover, out of the 59 patents published during this period, 32 have been published from 2012 onwards which further highlights the present interest of the researcher towards pyrimidine based anticancer agents. The promising activity displayed by these pyrimidine based scaffolds clearly places them in forefront as potential future drug candidates. The present compilation can be extremely beneficial for the medicinal chemists working on design and synthesis of anticancer drugs.

4,6-Diaryl/heteroarylpyrimidin-2(1H)-ones as a new class of xanthine oxidase inhibitors.

A series of 4,6-diaryl/heteroarylpyrimidones was synthesized employing silica-supported fluoroboric acid under solvent-free conditions in a microwave reactor. The catalytic influence of HBF4-SiO2 was investigated in detail to optimize the reaction conditions. The synthesized compounds were evaluated for in vitro xanthine oxidase (XO) inhibitory activity for the first time. Structure-activity relationship analyses are also presented. Among the synthesized compounds, VA-5, -9, -10, -12, -22, -23, and -25 were the active inhibitors with IC50 values ranging from 6.45 to 13.46 µM. Compound VA-25 with a pyridinyl ring as ring A and a thiophenyl ring as ring B emerged as the most potent XO inhibitor (IC50 = 6.45 µM) in comparison to allopurinol (IC50 = 12.24 µM). Some of the important interactions of VA-25 with the amino acid residues of the active site of XO were figured out by molecular modeling studies.

Tubulin inhibitors: a patent survey.

Tubulin is one of the most useful and strategic molecular targets for anticancer drugs. The dynamic process of microtubule assembly and disassembly can be blocked by various agents that bind to distinct sites in the ß-tubulin subunit. By interfering with microtubule function in vitro, these agents arrest cells in mitosis, eventually leading to cell death, by both apoptosis and necrosis. So far, three binding domains have been identified a) the colchicine site close to the α/ß interface, b) the area where the vinca alkaloids bind, and c) the taxane-binding pocket. This review compiles the patent literature up to 2013 and offers a detailed account of all the advances on Tubulin inhibitors (lead molecules) along with in depth knowledge about the number of novel scaffolds, modified analogs and derivatives of the lead molecules. Colchicine binding site remains the most explored site indicated by the patent survey as majority of the patents revolves around phenstatin and combretastatin based molecules where the key structural feature for tubulin inhibition is an appropriate arrangement of the two aromatic rings at an appropriate distance and optimal dihedral angle maximizing interactions with tubulin. A brief account of promising tubulin inhibitors in stages of clinical development and some strategies for the development of potent molecules overcoming the problem of drug resistance have also been discussed.

Synthesis and biological activity of novel antibacterial quinazolines.

Novel quinazolines, having interesting antibacterial activity have been prepared, characterized and tested against a panel of susceptible and resistant Gram positive and Gram negative organisms.

Amidine derived 1,3-diazabuta-1,3-dienes as potential antibacterial and antifungal agents.

Several 1-aryl-2-phenyl-4-piperidino-4-thioalkyl-1,3-diazabuta-1,3-dienes were prepared by the treatment of N-arylimino isothiocyanate with piperidine followed by S-alkylation with alkyl iodides in the presence of dry acetone and potassium hydroxide. The constitution of the products was supported by IR, PMR and mass spectral study. The compounds synthesized were tested in in vitro against E. coli, S. aureus, P. aeruginosa, B. cereus and B. subtilis and fungal stains, Candida albicans and Aspergillus niger. Standard drugs were also tested under identical conditions for comparing the results.