Two new myrsinol-type diterpene polyesters 3,5,13,17-tetra-O-acetyl-7-O-benzoyl-15-hydroxymyrsinol (1) and 3,5,13,17-tetra-O-acetyl-7-O-butanoyl-13-hydroxymyrsinol (2), with a tricyclic carbon skeleton have been isolated from Euphorbia decipiens Boiss. & Buhse. The structure elucidation of the isolated compounds was based primarily on HREIMS, EIMS, IR, UV, ID-, and 2D-NMR analyses, including COSY, HMQC, HMBC, and NOESY correlations. Compounds 1 and 2 also showed activity against urease enzyme. 相似文献
An efficient improved procedure for the synthesis of beta-acetamido carbonyl compounds is developed by a cobalt(II) chloride-catalyzed three-component coupling protocol. The procedure is also amenable to the synthesis of gamma-lactams by a three-component coupling reaction with use of 2-carbomethoxybenzaldehyde. The beta-acetamido carbonyl compounds derived from 2-carbomethoxybenzaldehyde are useful intermediates as they can be transformed to the corresponding gamma-lactams on treatment with base. 相似文献
Paeonins A and B, new monoterpene galactosides have been isolated from the chloroform-soluble fraction of the roots of Paeonia emodi and showed potent lipoxygenase inhibitory activity. The structures of 1 and 2 have been assigned on the basis of spectral analysis including one- and two-dimensional NMR techniques. 相似文献
Evidence is presented for the formation of a solid phase based on the smallest fullerene, C20, in thin diamond-like carbon films deposited by ultraviolet laser ablation from diamond onto nickel substrates at room temperature
in the presence of 10-4 torr of cyclohexane or benzene. Laser desorption mass spectrometry from the films shows the presence of C20, C21 and C22 species, while micro-Raman spectroscopy and electron diffraction from selected particles together with first principle density-functional
calculations, indicate a cubic solid with dodecahedral C20 cages as building blocks. Unlike solid C60 and fully protonated C20, which are bound by van der Waals forces, the proposed structure is stabilized by linking of the C20 dodecahedra with bridging carbon atoms at interstitial tetrahedral sites to form a face-centered-cubic lattice with 22 carbon
atoms per unit cell.
Received 10 October 2002 / Received in final form 24 December 2002 Published online 6 March 2003
RID="a"
ID="a"e-mail: zafar.iqbal@njit.edu 相似文献
The synthesis and characterization of homobimetallic complexes of VO(IV), Cr(II), Co(II), Ni(II), and Cu(II) with the chiral Schiff base (1S,2S)-N,N-1,2-Diphenylethylene-bis-(5-imino-1-phenyl-1,3-hexa-nedione) is reported. The metal ions occupy both compartments of the ligand; water molecules fill the coordination spheres to provide an octahedral environment around the central atoms. The antibacterial activity of both mono- and bimetallic complexes against a number of Gram-positive as well as Gram-negative bacteria has been tested and is discussed. 相似文献
Synthesis and characterization of molybdenum complex with tolbutamide (an oral antidiabetic drug) have been studied. The conductometric titration using monovariation method indicates that complex is non-ionic and of L2M type. Analytical data agree with the molecular formula (C12H17N2O3S)2Mo·2H2O. Structure of the complex was assigned as octahedral in which ligand molecules lie horizontally joining the central molybdenum atom and one water molecule, each attached vertically with the metal. Infra-red spectral studies confirm the coordination of sulphonyl oxygen on one side and enolic oxygen attached from other side with the metal ion. IR and 1H NMR studies support structure II proposed on the basis of analytical data. Magnetic susceptibility data suggested that the complex is diamagnetic. Thermal studies support the presence of ligand moieties and coordinated water. X-ray diffraction data also support the complex formation. 相似文献
The present paper deals with the synthesis and characterization of Schiff base complexes of pyrazinamide an antitubercular drug. Metals selected for complexation are copper, silver, gold, zinc, mercury, iron and cobalt. The complexes have been suitably synthesized and isolated in pure powdered form. Analytical data agrees with the compositions M(L), M′(L)2 and M″(L)2·2H2O, respectively where M = Ag, M′ = Cu, Au, Zn and Hg and M″ = Fe and Co, ligand metal ratios were also confirmed by monovariation method and Job’s method of continuous variation. Molar conductance values suggest the non ionic nature of the complexes. The tentative structure assigned to the complexes on the basis of stoichiometry and analytical data were further supported by spectral studies viz; IR, NMR, magnetic susceptibility and electronic spectra. A preliminary attempt has also been made to compare the potencies of metal complexes with parent drug. The Cu and Ag complexes are giving encouraging results. Particle size studies further suggest that the drug molecule undergoes reduction in size on complexation. 相似文献
This papers describes the in vitro interaction of copper(II) acetylsalicylate and copper(II) salicylate with genomic DNA isolated from human blood. The two drug substances were found to bind to DNA after incubation with whole blood over night. Bonding was confirmed by detection of separated DNA electrophoresis bands for copper, copper(II) acetylsalicylate, copper(II) salicylate, acetylsalicylic acid and salicylic acid. Drug–DNA interactions were observed during electrophoresis in the form of fragmentation by formation of two bands when compared to controls. Gel permeation chromatography parameters also confirmed the occurrence of fragmentation. The use of gel permeation chromatography parameters as a measure of fragmentation of DNA is discussed. The fragmentation of genomic DNA after incubation with copper(II) acetylsalicylate and copper(II) salicylate suggested that these drug substances might be responsible for cytotoxicity in vivo.