Carboxylesterases from the seeds of an underutilized legume, Mucuna pruriens; Isolation, purification and characterization

Two carboxylesterases (ME-III and ME-IV) have been purified to apparent homogeneity from the seeds of Mucuna pruriens employing ammonium sulfate fractionation, cation exchange chromatography on CM-cellulose, gel-permeation chromatography on Sephadex G-100 and preparative PAGE. The homogeneity of the purified preparations was confirmed by polyacrylamide gel electrophoresis (PAGE), gel-electrofocussing and SDS-PAGE. The molecular weights determined by gel-permeation chromatography on Sephadex G-200 were 20.89 kDa (ME-III) and 31.62 kDa (ME-IV). The molecular weights determined by SDS-PAGE both in the presence and absence of 2-mercaptoethanol were 21 kDa (ME-III) and 30.2 kDa (ME-IV) respectively, suggesting a monomeric structure for both the enzymes. The enzymes were found to have Stokes radius of 2.4 nm (ME-III) and 2.7 nm (ME-IV). The isoelectric pH values of the enzymes, ME-III and ME-IV, were 6.8 and 7.4, respectively. ME-III and ME-IV were classified as carboxylesterases employing PAGE in conjunction with substrate and inhibitor specificity. The K m of ME-III and ME-IV with 1-naphthyl acetate as substrate was 0.1 and 0.166 mM while with 1-naphthyl propionate as substrate the K m was 0.052 and 0.0454 mM, respectively. As the carbon chain length of the acyl group increased, the affinity of the substrate to the enzyme increased indicating hydrophobic nature of the acyl group binding site. The enzymes exhibited an optimum temperature of 45 °C (ME-III) and 37 °C (ME-IV), an optimum pH of 7.0 (ME-III) and 7.5 (ME-IV) and both the enzymes (ME-III and ME-IV) were stable up to 120 min at 35 °C. Both the enzymes were inhibited by organophosphates (dichlorvos and phosphamidon), but resistant towards carbamates (carbaryl and eserine sulfate) and sulphydryl inhibitors (p-chloromercuricbenzoate, PCMB). © 2011 Elsevier Ltd. All rights reserved

Synthesis and characterization of novel 1,2-oxazine-based small molecules that targets acetylcholinesterase

Thirteen 2-oxazine-based small molecules were synthesized targeting 5-lipoxygenase (LOX), and acetylcholinesterase (AChE). The test revealed that the newly synthesized compounds had potent inhibition towards both 5-LOX and AChE in lower micro molar concentration. Among the tested compounds, the most active compound, 2-(2-acetyl-6,6-dimethyl-4-phenyl-5,6-dihydro-2H-1,2-oxazin-3- yl)methyl-1H-isoindole-1,3(2H)-dione (2a) showed inhibitory activity towards 5-LOX and AChE with an IC50 values of 1.88, and 2.5 μM, respectively. Further, the in silico molecular docking studies revealed that the compound 2a bound to the catalytic domain of AChE strongly with a highest CDOCKER score of -1.18 kcal/mol when compared to other compounds of the same series. Additionally, 2a showed a good lipophilicity (log P = 2.66), suggesting a potential ability to penetrate the blood-brain-barrier. These initial pharmacological data revealed that the compound 2a could serve as a drug-seed in developing anti-Alzheimer's agents. © 2014 Elsevier Ltd. All rights reserved

Anti-tumor and anti-angiogenic activity of novel hydantoin derivatives: Inhibition of VEGF secretion in liver metastatic osteosarcoma cells

A series of new azaspiro bicyclic hydantoin derivatives has been designed and synthesized. Initially, the anti-proliferative effect of the hydantoin derivatives was evaluated against human ovarian cancer cells (SKOV-3 and OVSAHO) and murine osteosarcoma cells (LM8 and LM8G7). Among the tested compounds, 8-(3-fluorobenzyl)-1′-(4-(methylsulfonyl)benzyl)-8-azaspiro[bicyclo[3.2.1]octane-3,4′-imidazolidine]-2′,5′-dione (7h) and 8-(3,4-difluorobenzyl)-1′-(4-(methylsulfonyl)benzyl)-8-azaspiro[bicyclo[3.2.1]octane-3,4′-imidazolidine]-2′,5′-dione (7i) showed a significant anti-proliferative activity against the OVSAHO and LM8G7 cells. The real-time monitoring of the effect of the compounds 7h and 7i against the proliferation of LM8G7 was revealed that resulting IC50 values were 102 μM and 13 μM, respectively. We reasoned that the presence of fluorine atom at the 3rd position of the phenyl ring of the hydantoin side chain may determine the potency of the molecule. Furthermore, the compound 7i inhibited the tube formation of the mouse endothelial cells. Finally, the treatment of the compound 7i against the proliferation of LM8G7 cells demonstrated the down regulation of the secretion of VEGF, indicate the potential angioinhibitory effects. In conclusion, our findings demonstrate the suppression of the secretion of VEGF by LM8G7 cells by the compound 7i might contribute at least in part to the antitumor action

CHARACTERIZATION OF ALPHA-AMYLASE FROM THE SEEDS OF Mucuna pruriens

Amylases are hydrolytic enzymes which are widely distributed in nature, animals, plants and microorganisms. Amylases are of great significance in present-day biotechnology. In present study, amylases are isolated from the soaked seeds of Mucuna pruriens under extreme acidic conditions. Conventional protein purification techniques such as salt fractionation, ion exchange chromatography on CM-cellulose and sephadex G-75 was employed for the purification of amylase from the seeds of Mucuna pruriens. The amylase activity was eluted in one peak. The specific activity and yield of the purified amylase was 6.25 and 29.99, respectively. Native PAGE, SDS-PAGE and gel electrofocussing were employed to establish homogeneity of the purified amylase. SDS-PAGE and gel-filtration chromatography on sephadex G-75 was used to determine the molecular weight of the purified amylase. The purified amylase was nearly homogenous and its molecular weight was found to be 78.4 kDa. The optimum pH and temperature of the purified amylase were 7.0 and 50oC, respectively. The isolectric pH of the purified amylase was 7.2 and the activity was linear up to 60 minutes

Synthesis and biological evaluation of tetrahydropyridinepyrazoles ('PFPs') as inhibitors of STAT3 phosphorylation

The transcription factor STAT3 is constitutively overexpressed in many human tumors and hence represents a putative target for anticancer drug design. In this work, we describe the synthesis and biological evaluation of a novel chemotype, pyridine-fused pyrazoles ('PFPs') as inhibitors of STAT3 phosphorylation. The effect of the compounds synthesized was evaluated in cell proliferation assays of MCF-7 and HepG2 cancer cell lines and two of the compounds tested (12g and 12k) were found to show significant activity. Both compounds were also found to inhibit the proliferation of Hep3B, HUH-7 and PLC/PRF5 HCC cells in a dose-and time-dependent manner. Furthermore, we established in a DNA binding assay that one of the compounds (12g) was able to significantly inhibit the DNA binding ability of STAT3. Cytotoxicity of 12g against PC3 cells, which do not constitutively phosphorylate STAT3, was found to be minimal, hence lending further support for our mode-of-action hypothesis of this compound. We established for this structure a complete inhibition of CXCL12-induced cell invasion and associated wound healing in HCCLM3 cells, corroborating the proposed modulation of the STAT3 axis by 12g. Finally, molecular modeling was employed to evaluate the hypothesis of PFPs to bind to the SH2 domain of STAT3. Given the efficacy of PFPs in the biological systems studied here we propose their further evaluation in the context of STAT3-mediated cancer therapy

Molprint 2D-Based Identification and Synthesis of Novel Chromene Based Small Molecules that Target Pla2: Validation through Chemo-And Bioinformatics Approaches

Phospholipase A2 (PLA2) is known to regulate inflammation and hence it is considered as a validated drug-target by medicinal chemists. In this report, we have identified and considered a highly ranked ligand from the ZINC-drug-like compounds database that targets PLA2 via the MOLPRINT-2D based chemoinformatics drug-design approach. The computationally predicted lead molecule was found to contain a core moiety of a chromene ring, which is well known for its varied biological properties. Here, a novel and efficient retro-synthetic protocol for the synthesis of highly substituted chromene libraries was made. A one-pot synthesis of chromene was carried out using different aromatic primary alcohols, malononitrile and 4-hydroxy coumarin in the presence of a mild oxidant mixture called T3P®–DMSO, followed by a Suzuki coupling reaction to obtain the lead molecules. All of the tested compounds of the chromene series displayed inhibition of the venom PLA2 in the range of 12 to 68 μM. Among the tested compounds, 2-amino-4-(2′-methyl-[1,1′-biphenyl]-4-yl)-5-oxo-4,5-dihydropyrano[3,2-c]chromene-3-carbonitrile (7b) showed maximum inhibitory efficacy against venom PLA2 with an IC50 value of 12.5 μM. Furthermore, the designed PLA2 ligands bound to the active site of venom PLA2, whose binding affinity was comparable to nimesulide, indicating that the chromene moiety containing ligands could be novel lead-structures that serve as anti-inflammatory agents

A comparative study on q-deformed fermion oscillators

In this paper, the algebras, representations, and thermostatistics of four types of fermionic q-oscillator models, called fermionic Newton (FN), Chaichian-Kulish-Ng (CKN), Parthasarathy-Viswanathan-Chaichian (PVC), Viswanathan-Parthasarathy-Jagannathan-Chaichian (VPJC), are discussed. Similarities and differences among the properties of these models are revealed. Particular emphasis is given to the VPJC-oscillators model so that its Fock space representation is analyzed in detail. Possible physical applications of these models are concisely pointed out.Comment: 32 pages, 2 figures, to appear in Int. J. Theor. Phys. (IJTP

YREC: The Yale Rotating Stellar Evolution Code

The stellar evolution code YREC is outlined with emphasis on its applications to helio- and asteroseismology. The procedure for calculating calibrated solar and stellar models is described. Other features of the code such as a non-local treatment of convective core overshoot, and the implementation of a parametrized description of turbulence in stellar models, are considered in some detail. The code has been extensively used for other astrophysical applications, some of which are briefly mentioned at the end of the paper.Comment: 10 pages, 2 figures, ApSS accepte