Antioxidant, antiinflammatory and antiinvasive activities of biopolyphenolics

A large number of polyphenolic and heterocyclic compounds, i.e. 4-methylcoumarins, 4-methylthionocoumarins, xanthones, pyrazoles, pyrazolylacrylonitriles, flavones and isoflavones have been tested for their antioxidant activity towards NADPH-catalysed liver-microsomal lipid peroxidation with a view to establish their structure-activity relationship. Inhibition of microsomal lipid peroxidation by 7,8-dihydroxy-4-methylcoumarin (DHMC, 2) and 7,8-diacetoxy-4-methylcoumarin (DAMC, 3) was intriguing. We also found that dihydroxy and diacetoxy derivatives of 4-methylthionocoumarin were more potent in comparison to the corresponding coumarin derivatives in inhibiting TNF-α induced expression of ICAM-1. The effect of nine different xanthones has been examined on the modulation of cytokine-induced expression of ICAM-1 in human endothelial cells. 1,4-Dihydroxyxanthone (10) showed enhanced antioxidant activity as well as the inhibition of the expression of cell adhesion molecules, such as ICAM-1, VCAM-1 and E-selectin on endothelial cells in a concentration and time dependent manner. Antioxidant activity of different pyrazoles and pyrazolylacrylonitriles and antiinvasive activity of flavones and isoflavones against solid tumors have also been studied

Growth, spectral, optical, thermal, crystallization perfection and nonlinear optical studies of novel nonlinear optical crystal-Urea thiosemicarbazone monohydrate

Single crystals of organic nonlinear material urea thiosemicarbazone monohydrate (UTM) have been grown by slow evaporation method. The grown crystals were characterized by single crystal X-ray diffraction analysis reveals that sample crystallized in triclinic system with noncentrosymmetric space group P1. Powder XRD pattern confirmed that grown crystal posses highly crystalline nature. FTIR spectrum was recorded to identify the presence of functional groups and molecular structure was confirmed by H-1 NMR spectrum. Material confirmation of title compound has been performed by using mass spectroscopic analysis. Elemental composition of grown crystal was confirmed by energy-dispersive spectrometry (EDS). To study the crystalline perfection of the grown crystals, high-resolution X-ray diffraction (HR-XRD) study was carried out. Thermogravimetric and differential thermal analyses were employed to understand the thermal and physio-chemical stability of the synthesized compound. UV-Vis-NIR spectrum revealed the transmission properties of the crystal specimen. Relative SHG efficiency is measured by Kurtz and Perry method and found to about 0.89 times that of standard potassium dihydrogen phosphate (KDP) crystals

Growth, HR-XRD, optical, thermal, luminescence and nonlinear optical studies of novel organic nonlinear optical crystal: l-Threonine formate

The NLO single crystals of L-threonine formate (LTF) were grown by slow evaporation method in the molar ratio 1:1. The grown crystal was characterized by single crystal XRD, Powder XRD, HR-XRD, mass, thermal and UV-vis-NIR spectral analysis. Single crystal XRD analysis revealed that the crystal system belongs to tetragonal with cell parameters a = 7.86 angstrom, b = 7.86 angstrom and c = 11.07 angstrom. The sharp and well defined Bragg peaks observed in the powder XRD pattern confirm the crystalline nature of LTF compound. The structural perfection of the grown crystals has been analyzed by high-resolution X-ray diffraction (HR-XRD) analysis. Mass spectroscopic analysis determined the compound molecular weight from the full scan mass spectra. The optical properties of the grown crystal were calculated from UV transmission spectral analysis. Thermo gravimetric and differential thermal analysis reveals the thermal stability of the grown crystal. Second harmonic generation (SHG) of powdered LTF sample was tested using Nd:YAG laser and is found to be 1.21 times that of potassium dihydrogen orthophosphate. The fluorescence spectral study was carried out in the range of 280-500 nm and the optical band gap is estimated to be 3.042 e

Growth, HR-XRD, optical, thermal, luminescence and nonlinear optical studies of novel Organic nonlinear optical crystal: L-Threonine formate

The NLO single crystals of L-threonine formate (LTF) were grown by slow evaporation method in the molar ratio 1:1. The grown crystal was characterized by single crystal XRD, Powder XRD, HR-XRD, mass, thermal and UV-vis-NIR spectral analysis. Single crystal XRD analysis revealed that the crystal system belongs to tetragonal with cell parameters a = 7.86 angstrom, b = 7.86 angstrom and c = 11.07 angstrom. The sharp and well defined Bragg peaks observed in the powder XRD pattern confirm the crystalline nature of LTF compound. The structural perfection of the grown crystals has been analyzed by high-resolution X-ray diffraction (HR-XRD) analysis. Mass spectroscopic analysis determined the compound molecular weight from the full scan mass spectra. The optical properties of the grown crystal were calculated from UV transmission spectral analysis. Thermo gravimetric and differential thermal analysis reveals the thermal stability of the grown crystal. Second harmonic generation (SHG) of powdered LTF sample was tested using Nd:YAG laser and is found to be 1.21 times that of potassium dihydrogen orthophosphate. The fluorescence spectral study was carried out in the range of 280-500 nm and the optical band gap is estimated to be 3.042 e

An extensive investigation on nucleation, growth parameters, crystalline perfection, spectroscopy, thermal, optical, microhardness, dielectric and SHG studies on potential NLO crystal - Ammonium Hydrogen L-tartarte

Ammonium Hydrogen L-tartarte (AMT), an organic nonlinear optical crystal was grown by slow evaporation method at ambient temperature. Solubility, metastable zone width and induction period of Ammonium Hydrogen L-tartarte in aqueous solution were determined. Good quality crystals were selected and characterized by Single crystal XRD, HR-XRD, FT-IR, H-1 NMR, Mass, TGA-DTA, SEM, EDAX, optical and NLO studies. Single crystal XRD analysis revealed that the crystal system belongs to orthorhombic with cell parameters a = 7.65 angstrom, b = 7.85 angstrom and c = 11.07 angstrom. High-resolution-X-ray diffraction (HR-XRD) analysis was carried out to study the crystalline perfection of the grown crystal. H-1 NMR and FTIR spectrum thus confirmed the presence of functional groups of the grown crystal. Molecular mass of AMT was measured accurately by mass spectroscopic analysis. Surface features of the grown crystal were analyzed by SEM, AFM, chemical etching and the presence of elements in the compound was identified by EDAX analysis. Thermal behavior of the grown crystal has been studied by TG/DTA analysis. The recorded UV-Vis-NIR spectrum shows excellent transmission in the region of 190-1100 nm. The Vickers and Knoop's microhardness studies have been carried out on AMT crystals over a range of 10-50 g. Hardness anisotropy has been observed in accordance with the orientation of the crystal. Fluorescence spectral studies were carried in the range of 280-500 nm for the grown crystal. The SHG conversion efficiency and laser damage threshold were measured using an Nd: YAG laser (1064 nm)

Comparative specificities of Calreticulin Transacetylase to O-acetyl, N-acetyl and S-acetyl derivative of 4-methylcoumarins and their inhibitory effect on AFB1-induced genotoxicity in vitro and in vivo.

We have earlier conclusively established the Calreticulin Transacetylase (CRTAase) catalyzed modifications of functional proteins such as cytochrome-P450-linked mixed function oxidases (Cyt-P450-linked MFOs), NADPH cytochrome c reductase, and glutathione S-transferase by acetoxy derivatives of polyphenols. In this study, we have investigated the comparative specificities of CRTAase to N-acetyl derivative, 7-acetamido-4-methylcoumarin (7-N-AMC), O-acetyl derivative, 7-acetoxy-4-methylcoumarin (7-AMC), S-acetyl derivative, 7-thioacetyl-4-methycoumarin (7-S-AMC) and their parent compounds in the modulation of catalytic activities of aforesaid proteins. Special attention concentrated on the comparative inhibitory effect of aforesaid acetyl moiety on Cyt-P450-linked MFOs such as 7-ethoxyresorufin O-deethylase (EROD), pentoxyresorufin O-dealkylase (PROD) and aflatoxin B1 (AFB1)-induced genotoxicity in vitro and in vivo. The results clearly indicated that N-acetyl and O-acetyl derivatives were better substrates for CRTAase while the S-acetyl was found to be a poorer substrate. Our study involving atomic charge, charge density and molecular electrostatic potential (MEP) calculations indicated the pivotal role of electronegativity and charge distribution values of O, N and S atoms of the acetyl group at C-7 position of the 4-methylcoumarins in CRTAase activity. These facts reinforce our hypothesis that the CRTAase catalyzed modifications of the catalytic activities of aforesaid proteins by acetyl derivative of 4-methylcoumarins is probably due to acetylation of these proteins. © 2012 Elsevier Ltd

Mechanical Properties and Morphological Alterations in Fiber-Based Scaffolds Affecting Tissue Engineering Outcomes

Electrospinning is a versatile tool used to produce highly customizable nonwoven nanofiber mats of various fiber diameters, pore sizes, and alignment. It is possible to create electrospun mats from synthetic polymers, biobased polymers, and combinations thereof. The post-processing of the end products can occur in many ways, such as cross-linking, enzyme linking, and thermal curing, to achieve enhanced chemical and physical properties. Such multi-factor tunability is very promising in applications such as tissue engineering, 3D organs/organoids, and cell differentiation. While the established methods involve the use of soluble small molecules, growth factors, stereolithography, and micro-patterning, electrospinning involves an inexpensive, labor un-intensive, and highly scalable approach to using environmental cues, to promote and guide cell proliferation, migration, and differentiation. By influencing cell morphology, mechanosensing, and intracellular communication, nanofibers can affect the fate of cells in a multitude of ways. Ultimately, nanofibers may have the potential to precisely form whole organs for tissue engineering, regenerative medicine, and cellular agriculture, as well as to create in vitro microenvironments. In this review, the focus will be on the mechanical and physical characteristics such as porosity, fiber diameter, crystallinity, mechanical strength, alignment, and topography of the nanofiber scaffolds, and the impact on cell proliferation, migration, and differentiation

QSAR analysis of analogs of bis[2-(acylamino) phenyl] disulfides, 2-(acylamino)benzenethiols and S-[2-(acylamino) phenyl] alkanethioates as antihyperlipidemic agents <b></b>

1481-1486A series of antihyperlipidemic analogs of bis[2-(acylamino)phenyl]disulfides, 2-(acylamino) benzenethiols and S-[2-(acylamino)phenyl] alkanethioates has been subjected to quantitative structure activity relationship analysis. They show that the cholesteryl ester transfer protein inhibitors as determined in the human are having significant correlation with steric (Principle moment of inertia of X-component) and thermodynamic (logP and bend energy) properties of the molecule. Molecular modelling and QSAR analysis suggest that substitution at R1 with bulkier group is more favourable for cholesteryl ester transfer protein (CETP) inhibitory activity while keeping R2 unsubstituted or substituted with smaller groups results in more potent CETP inhibitors

Xanthones as inhibitors of microsomal lipid peroxidation and TNF-alpha induced ICAM-1 expression on human umbilical vein endothelial cells (HUVECs)

Xanthones bearing different functionalities, namely 1-hydroxyxanthone (1), 3-hydroxyxanthone (2), 1,4-dihydroxyxanthone (3), 2,6-dihydroxyxanthone (4), 1,2-diacetoxyxanthone (5), 2,6-diacetoxyxanthone (6), 3-methoxyxanthone (7), 1,3,7-trimethoxyxanthone (8) and 1,5-dihydroxy-6-methoxyxanthone (9) were synthesised and examined for their effect on nicotinamide adenine dinucleotide phosphate (NADPH)-catalysed liver microsomal lipid peroxidation and on tumour necrosis factor-alpha (TNF-alpha) induced expression of intercellular adhesion moledule-1 (ICAM-1) on endothelial cells, with a view to establish structure-activity relationship. Hydroxy- and acetoxyxanthones showed potent inhibitory effects on NADPH-catalysed lipid peroxidation and TNF-a induced expression of ICAM-1 on endothelial cells. (C) 2002 Elsevier Science Ltd. All rights reserved

Piper longum Linn. Extract inhibits TNF-α-induced expression of cell adhesion molecules by inhibiting NF-κB activation and microsomal lipid peroxidation

Recruitment of specific leukocyte subpopulations at the site of inflammation requires a series of cell adhesion molecule (CAM)-mediated interactions. The major CAMs, viz., intercellular adhesion molecule-1 (ICAM-1), VCAM-1 and E-selectin are expressed on endothelium in response to various cytokines or bacterial LPS. Here, we have evaluated the effect of Piper longum chloroform extract (PlCE) on TNF-α-induced expression of ICAM-1 on endothelial cells and on NADPH-catalyzed rat liver microsomal lipid peroxidation with a view to identify modulators for the expression of CAMs. We demonstrate that PlCE inhibits adhesion of neutrophils to endothelial monolayer. This inhibition is due to the ability of PlCE to significantly block the TNF-α-induced expression of CAMs, i.e. ICAM-1, VCAM-1 at 17.5 μg/ml concentration and E-selectin at 15 µg/ml concentration on human umbilical vein endothelial cells. The inhibition of ICAM-1, VCAM-1 and E-selectin by PlCE is mediated through inhibition of NF-κB in endothelial cells. To demonstrate the antioxidant activity of PlCE, we showed that PlCE inhibited the NADPH-catalyzed rat liver microsomal lipid peroxidation significantly. These results suggest a possible mechanism of anti-inflammatory as well as antioxidant activity of PlCE