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31.
Research on Chemical Intermediates - Since it has been cleared that a fake compound has been sold to us as cyanoform.  相似文献   
32.
Interactional studies of new flavonoid derivatives (Fl) with chicken blood ds.DNA were investigated spectrophotometrically in DMSO-H2O (9:1 v/v) at various temperatures. Spectral parameters suggest considerable binding between the flavonoid derivatives studied and ds.DNA. The binding constant values lie in the enhanced-binding range. Thermodynamic parameters obtained from UV studies also point to strong spontaneous binding of Fl with ds.DNA. Viscometric studies complimented the UV results where a small linear increase in relative viscosity of the DNA solution was observed with added optimal flavonoid concentration. An overall mixed mode of interaction (intercalative plus groove binding) is proposed between DNA and flavonoids. Conclusively, investigated flavonoid derivatives are found to be strong DNA binders and seem to be promising drug candidates like their natural analogues.  相似文献   
33.
Imidazolidine and thiazolidine-based isatin derivatives (IST-01–04) were synthesized, characterized, and tested for their interactions with ds-DNA. Theoretical and experimental findings showed good compatibility and indicated compound–DNA binding by mixed mode of interactions. The evaluated binding parameters, i.e., binding constant (Kb), free energy change (ΔG), and binding site sizes (n), inferred comparatively greater and more spontaneous binding interactions of IST-02 and then IST-04 with the DNA, among all compounds tested under physiological pH and temperature (7.4, 37 °C). The cytotoxic activity of all compounds was assessed against HeLa (cervical carcinoma), MCF-7 (breast carcinoma), and HuH-7 (liver carcinoma), as well as normal HEK-293 (human embryonic kidney) cell lines. Among all compounds, IST-02 and 04 were found to be cytotoxic against HuH-7 cell lines with percentage cell toxicity of 75% and 66%, respectively, at 500 ng/µL dosage. Moreover, HEK-293 cells exhibit tolerance to the increasing drug concentration, suggesting these two compounds are less cytotoxic against normal cell lines compared to cancer cell lines. Hence, both DNA binding and cytotoxicity studies proved imidazolidine (IST-02) and thiazolidine (IST-04)-based isatin derivatives as potent anticancer drug candidates among which imidazolidine (IST-02) is comparatively the more promising.  相似文献   
34.
Triphenyl(propyl‐3‐sulfonyl)phosphoniumtrifluoromethanesulfonate {[TPPSP]OTf} as a reusable, green and benign ionic liquid catalyst has been used in the Hantzsch four‐component (synthesis of polyhydroquinolines) and three‐component (synthesis of acridines) condensation reactions of 1,3‐diones, β‐ketoesters, aldehydes, ammonium acetate and aniline derivatives in the presence of 0.5 mol% of {[TPPSP]OTf} at room temperature under solvent‐free conditions. The new ionic liquid catalyst was fully characterized using infrared, 1H NMR, 13C NMR, 31P NMR, 19F NMR and mass spectroscopies, and thermogravimetric and derivative thermogravimetric analyses. Additionally, the recovered catalyst can be recycled at least five times in subsequent reactions without significant loss in catalytic activity. The new synthesis technique presented offers numerous advantages of safety, mild conditions, simplicity, short reaction time, high yields and easy workup compared to the traditional synthesis method. Twenty products have been reported for the first time. Copyright © 2016 John Wiley & Sons, Ltd.  相似文献   
35.
Vanadyl polyphosphates with a P/V ratio=2 (crystalline α-VO(PO3)2 and β-VO(PO3)2 as well as amorphous VO(PO3)2) were synthesized, starting from usually prepared precursor VO(H2PO4)2 but pursuing new methods using V2O5/H3PO4 as well as VOHPO4·1/2 H2O/H3PO4, too. The products were characterized by chemical analysis and X-ray diffractometry.In situ ESR spectroscopy was used as a tool to predict their catalytic activity in the ammoxidation reaction.  相似文献   
36.
The petroleum ether and ethyl acetate fractions of dried ground seeds of Piper nigrum Linn. afforded sixteen compounds (1-16) including one new insecticidal amide, pipwaqarine (1) and six constituents (3,4,6,7,11,15) previously unreported from this plant. The structure of (1) has been elucidated through extensive 1D-, 2D-NMR spectral studies as, 1-[13-(3',4'-methylenedioxyphenyl)-2E,4E,12E-tridecatrienoyl]-N-isopentylamide, while those of known constituents through comparison of spectral data. 1 exhibited toxicity of 30ppm against fourth instar larvae of Aedes aegypti Liston determined by WHO method. A portion of petroleum ether fraction was also subjected to GC and GC-MS analysis resulting in the identification of three compounds (17-19) using the NIST Mass spectral search program 1998 and Kovat's retention indices. Two of these compounds, 17 and 18, are reported for the first time from this plant.  相似文献   
37.
In [6] we analyzed the direct analytical nodal methods (ANM) of indexl and show that the corresponding mathematical methods are equivalent to the physical ones when the components of the matrices are calculated by generalized Radau reduced integration. In this article we extend the theorem 8 of [7] to the polynomial nodal methods (PNM) (exact calculation of moments) which are thus the order ofO(h l+3?δ l0. We also show that the analytical nodal methods are only the order ofO(h l+2). Forl = 0 our numerical results confirm our theoretical results.  相似文献   
38.
In the title salt, C14H18N22+·2C9H5N4O, the 1,1′‐diethyl‐4,4′‐bipyridine‐1,1′‐diium dication lies across a centre of inversion in the space group P21/c. In the 1,1,3,3‐tetracyano‐2‐ethoxypropenide anion, the two independent –C(CN)2 units are rotated, in conrotatory fashion, out of the plane of the central propenide unit, making dihedral angles with the central unit of 16.0 (2) and 23.0 (2)°. The ionic components are linked by C—H...N hydrogen bonds to form a complex sheet structure, within which each cation acts as a sixfold donor of hydrogen bonds and each anion acts as a threefold acceptor of hydrogen bonds.  相似文献   
39.
In this paper, we give the explicit formula for the zonal spherical function on the Lie ball in ?n.  相似文献   
40.
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