Determination of berberine and berberrubine in rabbit plasma by capillary electrophoresis with amperometric detection and its application to pharmacokinetic study

A simple and selective method based on capillary electrophoresis with amperometric detection has been developed for the separation and determination of berberine (BB) and berberrubine (BBR) in rabbit plasma. The working electrode was a 150 μm diameter platinum microelectrode at a detection potential of +1.1 V (versus Ag/AgCl). The analytes could be well separated within 6 min in a 50 cm length fused-silica capillary at a separation voltage of 15 kV in a 50 mmol/L phosphate buffer (pH 6.0). Calibration curve was linear over the range of 0.002-20 μg/mL. The detection limits (S/N = 3) were 1.0 and 0.8 ng/mL for BB and BBR, respectively. Relative standard deviations (R.S.D.) of not more than 6.0 % were obtained for both migration times and electrophoretic peak area. The proposed method was successfully used to analyze the drugs in samples of rabbit plasma for pharmacokinetic study.Colegio de Farmacéuticos de la Provincia de Buenos Aire

1,1′-(Butane-1,4-diyl)di-1H-imidazole–benzene-1,3,5-triol–water (1/1/1)

The asymmetric unit of the title compound, C10H14N4·C6H6O3·H2O, contains one mol­ecule of benzene-1,3,5-triol, two half-molecules of 1,1′-butane-1,4-diyldi-1H-imidazole (each molecule is centrosymmetric) and one solvent water mol­ecule. In the crystal structure, inter­molecular O—H⋯O and O—H⋯N hydrogen bonds link all mol­ecules into a three-dimensional supra­molecular network

4-(2,2-Difluoro-1,3-benzodioxol-4-yl)-1H-pyrrole-3-carbonitrile

In the title compound, C12H6F2N2O2, the 2,2-difluoro-1,3-benzodioxole ring system is approximately planar [maximum deviation = 0.012 (2) Å] and its mean plane is twisted with respect to the pyrrole ring, making a dihedral angle of 2.51 (9)°. In the crystal, N—H⋯N hydrogen bonds link the mol­ecules into chains running along the a axis. π–π stacking is also observed between parallel benzene rings of adjacent mol­ecules, the centroid–centroid distance being 3.7527 (13) Å

Hexaaqua­nickel(II) bis­{4-[(2-chlorothia­zol-5-yl)meth­oxy]benzoate} dihydrate

In the title compound, [Ni(H2O)6](C11H7ClNO3S)2·2H2O, the NiII atom lies on an inversion center and is six-coordinate in an octa­hedral environment of water mol­ecules. The cation and anion are linked through O—H⋯O hydrogen bonding involving the coordinated and uncoordinated water mol­ecules into a three-dimensional network

(Z)-N-{3-[(6-Chloro­pyridin-3-yl)meth­yl]-1,3-thia­zolidin-2-yl­idene}cyanamide

The asymmetric unit of the title compound, C10H9ClN4S, common name thia­cloprid, comprises two mol­ecules. In both mol­ecules, the thia­zolidine rings are almost planar (with r.m.s. deviations of 0.016 and 0.065 Å) and form dihedral angles of 73.36 (6) and 70.25 (8)° with the 2-chloro­pyridine rings. In the crystal, inter­molecular C—H⋯N hydrogen bonds links the mol­ecules into chains propagating in [01]

catena-Poly[[tetra­aqua­zinc(II)]-μ-1,3,4-thia­diazol-2,5-diyldithio­diacetato-κ2 O:O′]

In the title linear coordination polymer, [Zn(C6H4N2O4S3)(H2O)4]n, the ZnII atom is coordinated by four O atoms from four water mol­ecules and two O atoms from two [5-(carb­oxyl­atomethyl­sulfan­yl)-1,3,4-thia­diazol-2-ylsulfan­yl]acetate units in an octa­hedral coordination environment. The chains are linked into a three-dimensional supra­molecular network via O—H⋯O and O—H⋯N hydrogen bonds

3,3′-(Butane-1,4-di­yl)diimidazole-1,1′-diium bis­(triiodide)

The cations and anions of the salt, C10H16N4 2+·2I3 −, are linked by N—H⋯I hydrogen bonds and π–π stacking inter­actions(with interplanar distances of 3.575 and 3.528 Å) into a three-dimensional supra­molecular network. The asymmetric unit contains two anions and two half-cations; each cation is centrosymmetric

Bis[1,1′-(1,3-phenyl­enedimethyl­ene)di(1H-imidazol-3-ium)] β-octa­molybdate

In the title compound, (C14H16N4)2[Mo8O26], the β-octa­molybdate anion is centrosymmetric. N—H⋯O hydrogen bonds link the diimidazolium cations and the polyoxidoanions into a chain structure along [100]. π–π inter­actions between the imidazole rings and between the imidazole and benzene rings [centroid–centroid distances = 3.611 (2) and 3.689 (3) Å, respectively] connect the chains

Di-μ-chlorido-bis­{[1,2-bis­(pyridin-2-ylmeth­oxy)benzene-κ4 N,O,O′,N′]chloridocadmium}

In centrosymmetric dinuclear title compound, [Cd2Cl4(C18H16N2O2)2], the CdII atom is seven-coordinated in a penta­gonal–bipyramidal environment defined by two N atoms and two O atoms from one ligand and three Cl− anions, two of which are bridging. A π–π inter­action between adjacent pyridine rings [centroid–centroid distance = 3.773 (1) Å] further stablizes the dimer

catena-Poly[[[diaqua­manganese(II)]-bis­[μ-1,3-bis­(1H-imidazol-1-ylmeth­yl)benzene-κ2 N 3:N 3′]] dinitrate]

In the title compound, {[Mn(C14H14N4)2(H2O)2](NO3)2}n, the MnII ion is located on an inversion center and is coordinated by four N atoms from four 1,3-bis­(1H-imidazol-1-ylmeth­yl)benzene (L) ligands and two water mol­ecules in a distorted octa­hedral geometry. Two L ligands are related by a centre of symmetry and bridge MnII ions, forming a positively charged polymeric chain in [101]. Uncoordinated nitrate anions further link these chains into layers parallel to the ac plane via O—H⋯O hydrogen bonds