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61.
ABSTRACT: BACKGROUND: Aerva javanica (Burm. f.) Juss. ex Schult. (Amaranthacea) is traditionally used for the treatment of wound healings, cough, diarrhoea, ulcer and hyperglycaemia. The current study was aimed to fractionate and isolate bioactive compounds and ultimately to evaluate their anti-ulcereogenic potential. RESULTS: In order to achieve these aims, the fractionation, purifications and then biological potential determination of the isolated compounds was carried out. For purification purpose, initially extraction of the plant material was done with aqueous MeOH in the order of increasing polarity by using solvent-solvent extraction method. Phytochemical analysis revealed the presence of three compounds, 3-hydroxy-4 methoxybenzaldehyde (1), ursolic acid (2) and (E)-N-(4-hydroxy-3-methoxyphenethyl)-3-(4-hydroxy-3-ethoxyphenyl) acryl amide (3). Inhibition of urease activity of various fractions revealed that ethyl acetate fraction showed significant activity (P <0.05) as compared to other fractions. (E)-N-(4-hydroxy-3- methoxyphenethyl)-3-(4-hydroxy-3-ethoxyphenyl) acryl amide (3) showed marked anti ulcer activity (P <0.05). CONCLUSION: These results suggested the mild potential of A. javanica against ulcer.  相似文献   
62.
A systematic study of the product((E(2_2~+)/E(2_1~+))*B(E2)↑) is carried out in the major shell space Z=50-82,N=82-126 within the framework of the asymmetric rotor model where the asymmetry parameter γ0reflects change in the nuclear structure.A systematic study of the product((E(2+)/E(2+))*B(E2)↑) with neutron number N is also discussed.The product((E(2_2~+)/E(2_1~+))*B(E2)↑) provides a direct correlation with the asymmetry parameter γ0.The effect of subshells is visible in Ba-Gd nuclei with N 82,but not in Hf-Pt nuclei with N 104.We study,for the first time,the dependency of the product((E(2_2~+)/E(2_1~+))*B(E2)↑) on the asymmetry parameterγ0.  相似文献   
63.
We examine the effect of dissipation on travelling waves in nonlinear dispersive systems modelled by Benjamin–Bona–Mahony (BBM)-like equations. In the absence of dissipation, the BBM-like equations are found to support soliton and compacton /anticompacton solutions depending on whether the dispersive term is linear or nonlinear. We study the influence of increasing nonlinearity of the medium on the soliton and compacton dynamics. The dissipative effect is found to convert the solitons either to undular bores or to shock-like waves depending on the degree of nonlinearity of the equations. The anticompacton solutions are also transformed to undular bores by the effect of dissipation. But the compactons tend to vanish due to viscous effects. The local oscillatory structures behind the bores and /or shock-like waves in the case of solitons and anticompactons are found to depend sensitively both on the coefficient of viscosity and solution of the unperturbed problem.  相似文献   
64.
Lysozyme is often used as a model protein to study interaction with drug molecules and to understand biological processes which help in illuminating the therapeutic effectiveness of the drug. In the present work, in vitro interaction studies of 1-{(2-hydroxyethyl)amino}-2-amino-1,2-dideoxy-d-glucose triphenyl tin (IV) (GATPT) complex with lysozyme were carried out by employing various biophysical methods such as absorption, fluorescence, and circular dichroism (CD) spectroscopies. The experimental results revealed efficient binding affinity of GATPT with lysozyme with intrinsic binding (Kb) and binding constant (K) values in the order of 105 M−1. The number of binding sites and thermodynamic parameters ΔG, ΔH, and ΔS at four different temperatures were also calculated and the interaction of GATPT with lysozyme was found to be enthalpy and entropy driven. The CD spectra revealed alterations in the population of α–helical content within the secondary structure of lysozyme in presence of GATPT complex. The morphological analysis of the complex with lysozyme and lysozyme-DNA condensates was carried out by employing confocal and SEM studies. Furthermore, the molecular docking studies confirmed the interaction of GATPT within the larger hydrophobic pocket of the lysozyme via several non-covalent interactions.  相似文献   
65.
Natural products derived from marine sponges have exhibited bioactivity and, in some cases, serve as potent quorum sensing inhibitory agents that prevent biofilm formation and attenuate virulence factor expression by pathogenic microorganisms. In this study, the inhibitory activity of the psammaplin-type compounds, psammaplin A (1) and bisaprasin (2), isolated from the marine sponge, Aplysinella rhax, are evaluated in quorum sensing inhibitory assays based on the Pseudomonas aeruginosa PAO1 lasB-gfp(ASV) and rhlA-gfp(ASV) biosensor strains. The results indicate that psammaplin A (1) showed moderate inhibition on lasB-gfp expression, but significantly inhibited the QS-gene promoter, rhlA-gfp, with IC50 values at 14.02 μM and 4.99 μM, respectively. In contrast, bisaprasin (2) displayed significant florescence inhibition in both biosensors, PAO1 lasB-gfp and rhlA-gfp, with IC50 values at 3.53 μM and 2.41 μM, respectively. Preliminary analysis suggested the importance of the bromotyrosine and oxime functionalities for QSI activity in these molecules. In addition, psammaplin A and bisaprasin downregulated elastase expression as determined by the standard enzymatic elastase assay, although greater reduction in elastase production was observed with 1 at 50 μM and 100 μM. Furthermore, the study revealed that bisaprasin (2) reduced biofilm formation in P. aeruginosa.  相似文献   
66.
67.
The present work focuses on the clouding phenomenon in an amphiphilic drug [amitriptyline (AMT), which is a tricyclic antidepressant] solution. A 50-mM AMT solution prepared in 10 mM of sodium phosphate (SP) buffer was taken where the cloud point (CP) was found to decrease with increasing pH. The same CP decreasing trend (with pH increase) followed in the presence of a fixed concentration (50 mM) of added salts [NaBr, and tetra-n-butylammonium bromide (TBuAB)]. The addition of increasing amounts of quaternary bromides (tetramethylammonium bromide, tetraethylammonium bromide, tetra-n-propylammonium bromide, TBuAB, and tetra-n-pentylammonium bromide) to 50 mM of AMT solution (prepared in 10 mM of SP buffer) caused continuous increase in CP, which was found to be dependent upon the alkyl chain length of that particular salt. The similar type of CP increase was also observed in the presence of conventional (cetyltrimethylammonium bromide and tetradecyltrimethylammonium bromide) and gemini surfactants [bis(hexadecyldimethylammonium)hexane, bis(hexadecyldimethylammonium)pentane, and bis(hexadecyldimethylammonium)butane]. The overall behavior was discussed in terms of electrostatic interactions, micellar growth, and mixed micelle formation.  相似文献   
68.
New oxygen carriers have been synthesized by the interaction of the CuII/NiII derivative of the bis(5-nitroindazolyl)methane complex with 14-membered 1,8-dihydro-1,3,6,8,10,13-hexaazacyclotetradecane (M-mac), where M=FeIII, NiII, CoII, to yield binuclear complexes. These complexes have been characterized by physico-chemical methods: elemental analysis, i.r., 1H-n.m.r., 13C-n.m.r., 2D cosy n.m.r., e.p.r., u.v.–vis. spectroscopy and cyclic voltammetry. A representative binuclear FeIII–CuII complex was chosen to interact with H2O2 to elucidate the mechanistic pathway of oxygen binding in solution spectrophotometrically, and also by cyclic voltammetry. Hydrogen peroxide exhibits two mechanisms for binding, either (i) homolysis or (ii) heterolytic cleavage. The mode of H2O2 binding can be hazardous in (i) due to the threat of oxidative damage to the cellular structure, proteins and metabolites, or eco-friendly as in (ii) which produces innocuous products such as water and dioxygen. This study aims to combat the problems associated with H2O2 binding in nature by producing a parallel study on model compounds.  相似文献   
69.
Let R be a ring and \({\mathbb{N}}\) be the set of all non-negative integers. A family of maps \({D=\{d_n\}_{n \in\mathbb{N}}}\) is said to be Jordan triple higher derivable if \({d_n(aba)=\sum \nolimits_{p+q+r=n} d_p(a)d_q(b)d_r(a)}\) holds for all \({a,b \in R}\), where d 0 = I R , (the identity map on R). In this paper, we determine Jordan triple higher derivable map on a ring R, which contains a nontrivial idempotent which is automatically additive. An immediate application of our main result shows that every Jordan triple higher derivable map becomes higher derivation on R.  相似文献   
70.
The present paper reports the preparation of poly (3,4‐ethylenedioxythiophene) (PEDOT) ferrimagnetic conducting polymer composite by incorporation of ferrite particles in the polymer matrix by emulsion polymerization. Synthesis of PEDOT–γ‐Fe2O3 composite was carried out by chemical oxidative polymerization of EDOT with ferrite particles in the presence of dodecylbenzenesulfonic acid (DBSA) that works as dopant as well as surfactant in aqueous medium. The resulting conducting composite possesses saturation magnetization (Ms) value of 20.56 emu/g with a conductivity of 0.4 Scm?1, which was determined by VSM and four probe technique, respectively. B‐H curve reveals that ferrimagnetic particles of γ‐Fe2O3 show super‐paramagnetic behavior at room temperature which was also observed in PEDOT–γ‐Fe2O3 composite. The resulting conducting ferrimagnetic composite shows microwave absorption loss of 18.7–22.8 dB in the frequency range of 12.4–18 GHz. Thermogravimetric analysis of the composite revealed that the composite is thermally stable up to 230°C. The characterization of the PEDOT–γ‐Fe2O3 composite was carried out using XRD and FTIR spectroscopy. Copyright © 2007 John Wiley & Sons, Ltd.  相似文献   
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