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
Journal of Radioanalytical and Nuclear Chemistry - Activity concentrations of natural (40K, 226Ra, 228Ra, 232Th, 238U) and artificial (134Cs, 137Cs) radionuclides were measured in powdered milk... 相似文献
Multiple valued quantum logic is a promising research area in quantum computing technology having several advantages over binary quantum logic. Adder circuits as well as subtractor circuits are the major components of various computational units in computers and other complex computational systems. In this paper, we propose a quaternary quantum reversible half-adder circuit using quaternary 1-qudit gates, 2-qudit Feynman and Muthukrishnan-Stroud gates. Then we propose a quaternary quantum reversible full adder and a quaternary quantum parallel adder circuit. In addition, we propose a quaternary quantum reversible parallel adder/subtractor circuit. The proposed designs are compared with existing designs and improvements in terms of hardware complexity, quantum cost, number of constant inputs and garbage outputs are reported.
In the present work, ab-initio calculations are performed to investigate cooperativity effects between chalcogen bond and H···π interactions in XHY···NCH···C6H6 and XHY···CNH···C6H6 complexes, where X = F, Cl, Br, CN, NC, and Y = S, Se. The nature of these interactions and the mechanism of cooperativity are studied by means of quantum theory of atoms in molecules, noncovalent interaction index, many-body analysis of interaction energy and electron density shift analysis. For each ternary complex, the shortening of the Y···N(C) distance is more pronounced than that of the H···π. The cooperative energies of these complexes are all negative which demonstrate a positive cooperativity between the Y···N(C) and H···π interactions. The many-body analysis of interaction energy reveals that the two-body energy term has the largest contribution to the total interaction energies of ternary complexes. A good linear correlation is established between the three-body energy and cooperative energy values in the ternary systems. The cooperative energies of XHY···CNH···C6H6 complexes indicate a larger sensitivity on the polarity of solvent than XHY···NCH···C6H6 ones. 相似文献
In this work the phase equilibrium of an aqueous two phase system (ATPS) containing polypropylene glycol (PPG, molecular weight = 425 kg·mol?1) and NaClO4 was investigated at atmospheric pressure and at 288.15 and 298.15 K. Two phase regions and composition of phases were determined. Our results show that as the temperature increases, the two-phase region expands. Also, the extended UNIQUAC (E-UNIQUAC) equation was used to correlate the equilibrium data. To reduce the number of adjustable parameters, ATPSs composed of PEG and PPG were collected from the literature and simultaneously correlated using the E-UNIQUAC model. Also, the effect of temperature on the liquid–liquid equilibrium (LLE) was considered by using temperature-dependent parameters. In the modeling, two different scenarios were supposed. In the first, polymer and salt were treated as solutes (Case A), while in the second, the pseudo-solvent approach was considered (Case B). The results showed good agreement with experimental data in both cases. The average absolute deviation of the model using Case B was about 0.2% and that for Case A was about 2% in the ATPS composed of PEG. Meanwhile, the reported errors in the ATPS containing PPG for Case A and Case B were almost equal. 相似文献
PEG-bound aldehydes undergo zinc-mediated Barbier allylation to form homoallylic alcohols, which on further reaction with various aldehydes in the presence of BF3·Et2O through a Prins cyclization afford 4-hydroxytetrahydropyrans and 4-fluorotetrahydropyrans. 相似文献
Summary Bis(acetylacetonato)VOII,–CoII,–NiII,–CuII,–ZnII, –UO
2II
and tris(acetylacetonato)FeIII react with benzohydroxamic acid to yield the corresponding mixed ligand complexes as a result of displacement of one acetylacetone molecule. Intermolecular association may be the reason for six-coordination geometry around the metal ions. A t.g.a. study of the complexes shows, in most cases, initial loss of alcohol and water molecules associated with the complexes; subsequent decomposition steps are characterised by very sharp weight loss. The photochemical stability of the complexes has been studied. Intraligand excitation causes a decomposition in the case of FeIII and VOII-complexes but no detectable effect for CoII, NiII, CuII, ZnII, or UO
2II
-complexes. 相似文献
New mixed ligand complexes of benzoyldithiocarbazate (H2BDT) have been synthesized and characterized by elemental analyses, spectral studies (i.r., u.v.–vis., mass), thermal analysis and electrical conductivity measurements. The complexes have the general formulae: [M2(BDT)(OX)2] · xH2O; [Co2(BDT)(OX)2(H2O)4]; [M(HBDT)(OX)-(H2O)], [Ni(BDT)(py)2]n and [Ni(BDT)(L)]n where M = MnII, NiII and CuII; BDT = dithiocarbazate dianion; OX = 8-hydroxyquinolinate; x = 1 or 2; M = ZnII or CdII; HBDT = dithiocarbazate anion and L = 2,2-bipyridyl or 1,10-o-phenanthroline. For the [M2(BDT)(OX)2] · xH2O, [Co2(BDT)(OX)2(H2O)4], [Ni(BDT)(py)2]n and [Ni(BDT)(L)]n complexes, benzoyldithiocarbazate acts as a dibasic-tetradentate ligand in the enol form via the enolic oxygen, the hydrazide nitrogens and the thiolate sulphur, while it acts as a monobasic-tridentate ligand in the keto form in the [M(HBDT)(OX)(H2O)] complexes. The thermal behaviour of the complexes has been studied by t.g.–d.t.g. techniques. Kinetic parameters of the thermal decomposition process have been computed by Coats–Redfern and Horowitz–Metzger methods. It is obvious that the thermal decomposition in the complexes occurs directly at the metal–ligand bonds except for the ZnII and CdII complexes in which decomposition seems to be at a point in the benzoyldithiocarbazate moiety. From the calculated kinetic data it can be concluded that the dehydration processes in all complexes have been described as phase-boundary controlled reactions. The activation energy values reveal that the thermal stabilities of the homobimetallic complexes lie in the order: MnII < NiII < CoII, while the monomeric CdII complex has more enhanced thermal stability than the ZnII complex. 相似文献
In this work chitin was extracted chemically from shrimp shells. Seventeen Bacillus isolates were screened for chitinolytic activity. The chitinolytic strains of Bt. were screened at different temperatures and pHs for their hydrolytic potentials. By using a pair of specific primers, endochitinase gene was amplified from SBS Bt-5 strain through PCR, and then cloned into pTZ57 TA cloning vector and transferred in Escherichia coli DH5α strain. The sequenced gene (GenBank Accession No: HE995800) consists of 2031 nucleotides capable of encoding 676 residues. The protein consisted of three functional domains with a calculated molecular mass of 74.53 kDa and a pI value of 5.83. The amino acid sequence of chi gene showed 99% similarity to the genes of Bt MR11 endochitinase, Bt serovar kurstaki chitinase (kchi), Bt strain MR21 endochitinase and Bacillus cereus B4264. 相似文献
New covalently linked sulfonic acid modified silicas have been formed and characterised and their catalytic Brönsted activity evaluated. Thus phenylmercaptoethyltrimethoxysilane, (MeO)3SiCH2CH2SC6H5 and benzylmercaptoethyltrimethoxysilane, (MeO)3SiCH2CH2SCH2C6H5, were used to prepare the corresponding T-functional silica derivatives silica CH2CH2SC6H4-4-SO3H and silica CH2CH2SCH2C6H4-4-SO3H by grafting on commercial silica, followed by sulfonation of the aryl group. Solid-state NMR, DTA and surface area characteristics of the materials are reported. The mercaptophenylsulfonic acid materials are thermally robust highly efficient solid catalysts for a range of transformations including, esterification, etherification and carbonyl group protection. An apparent pore size effect on rate of conversion was observed. The mercaptobenzylsulfonic acid materials were comparatively unstable. 相似文献