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Himanshu Sharma Mohini Mourya Debanjan Guin Yogesh C. Joshi Mahabeer P. Dobhal Ashok K. Basak 《Tetrahedron letters》2017,58(18):1727-1732
Selective dehydrogenation of 2-amino-3-cyano 4H-chromenes to the corresponding 2-iminochromenes mediated by diisopropyl azodicarboxylate under neutral conditions is reported. The dehydrogenation reaction is compatible with phenolic hydroxyl group and generates iminochromene in high yields. The methodology provides an easy access to coumarin and N-tosyl 2-amino-3-cyano-4-aryl 4H-chromenes. 相似文献
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The growth morphology of crystals of zinc tris(thiourea) sulphate (ZTS) is investigated experimentally, and computed using
the Hartman-Perdok approach. Attachment energies of the observed habit faces are calculated for determining their relative
morphological importance. A computer code is developed for carrying out these calculations. A special procedure is adopted
for computing the cohesive energy of a slice of the structure parallel to any rational crystallographic plane. For estimating
the cohesive energies, formal charges on the experimentally determined atomic positions in the molecules of ZTS are calculated
by ab initio molecular-orbital computations, with wave functions obtained by the Hartree-Fock procedure. Fairly good agreement with the
observed crystal morphology is obtained for a model of growth mechanism in which ZTS is assumed to exist in solution sa szinc
tris(thiourea) ions and sulphate ions. 相似文献
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The d + d, t + p and h + n relative wavefunctions and their asymptotic normalizations are considered in the framework of the generator coordinate method
(GCM) and compared with ATMS (amalgamation of two-body correlation into multiple scattering processes) method which used the
realistic Reid soft core interaction. The asymptotic normalization of relative wavefunctions provide various coupling constants,
the cluster probability amplitude (the so-called Z
1/2-factor) and matter RMS radii. These wavefunctions are also used to obtain 4He − d − d, 4He − t − p and 4He − h − n vertex functions in the virtual decay of 4He. The extrapolation of vertex functions for negative values of q
2 upto the corresponding poles provide the vertex constants which are comparable with other estimates. It is noticed that in
GCM the coupling constants C
2 for 4He − d − d vertex is less than 2 as has been obtained in the forward dispersion relation technique. 相似文献
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Kulthe SS Inamdar NN Choudhari YM Shirolikar SM Borde LC Mourya VK 《Colloids and surfaces. B, Biointerfaces》2011,88(2):691-696
Pluronic block copolymers offer affluent phase behavioral characteristics and are extensively investigated for drug delivery applications. Hydrophobic Pluronics produce larger aggregates whereas hydrophilic Pluronics often generate small-sized micelles in aqueous milieu. To overcome the limitations and combine the advantages of different kinds of Pluronics the mixing of such two types of Pluronics is studied here, especially for hydrophobic Pluronic L81 and relatively hydrophilic Pluronic P123. Critical micelle concentration (CMC) of the developed binary mixtures was 0.032 mg/ml as evidenced from pyrene fluorescence spectroscopy and is located in between that of the individual Pluronics. Dynamic light scattering (DLS) showed very small particle sizes (~20 nm) and low polydispersity indices for most of the mixed micelles. Transmission electron microscopy (TEM) demonstrated spherical shape of micelles. Based upon the ratio of hydrophobic and hydrophilic Pluronics, dispersions of varied stability were obtained. With 0.1/1.0 wt.% and 0.5/3.0 wt.% of Pluronic L81/P123, stable dispersions were obtained. Stability was assessed from turbidity measurement, size analysis and clarity of dispersion on standing. Micelles were also found to be stable in bovine serum albumin (BSA) solution. Mixed micelles showed fairly high entrapment efficiency, loading capacity and sustained release profile for aceclofenac (Acl), a model hydrophobe. Presence of salt lowered Acl solubilization in micelles. Thermodynamic parameters for Acl solubilization in mixed micelles revealed high partition coefficient values and spontaneity of drug solubilization. Thus, the developed novel mixed micelles hold promise in controlled and targeted drug delivery owing to their very small size, high entrapment efficiency and stability. 相似文献
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Mourya SK Dubey S Durgabanshi A Shukla SK Esteve-Romero J Bose D 《Journal of AOAC International》2011,94(4):1082-1088
Presently, disulfiram is used in aversion therapy for recovering alcoholics. It acts by inhibiting aldehyde dehydrogenase, leading to high blood levels of acetaldehyde. A simple direct injection micellar liquid chromatographic procedure was developed to determine disulfiram in illicit preparations (ayurvedic, herbal, divine ash, and traditional medicine), as well as in pharmaceuticals and biological samples (urine). After application of a predictive optimization strategy, the proposed method was developed using a 0.1 M sodium dodecyl sulfate-butanol 4% (v/v) buffered to pH 7 as the mobile phase at a flow rate of 1 mL/min, an octyl silyl (C8) 150 mm column, and diode array detection at 248 nm. Under the above conditions, the analysis time was below 8 min. Validation studies were based on U.S. Food and Drug Administration guidelines. The LOD (3 x SD criterion) was 15 ng/mL and LOQ (10 x SD criterion) was 70 ng/mL for disulfiram. The intraday and interday precisions were below 3.5%, recoveries were in the range of 97-102%, and robustness was below 3%. The optimized and validated micellar liquid chromatographic method was successfully applied to the determination of disulfiram in ayurvedic, herbal, divine ash, and other samples. The procedure developed could also be used in the fields of QC, routine analysis, and pharmacokinetic studies. 相似文献