Udai P. Singh

The effect of histidine on the structure and antitumor activity of metal-5-halouracil complexes

The ternary complexes of Mn(II), Co(II), Ni(II), Cu(II), Zn(II), and Cd(II) ions with 5-halouracils, viz., 5-fluorouracil (5FU), 5-chlorouracil (5ClU), and 5-bromouracil (5BrU), and the biologically important ligand L-histidine (HISD) have been synthesized and characterized by elemental analysis, conductance measurements, infrared spectra, electronic spectra, and magnetic moment (room temperature) measurements. On the basis of these studies, the structures of the complexes have been proposed. All these ternary complexes were screened for their antitumor activity against Daltons lymphoma in C3H/He mice. It was found that only Mn(II)-5BrU-HISD, Co(II)-5BrU-HISD, Cu(II)-5ClU-HISD, Cu(II)-5BrU-HISD, Zn(II)-5FU-HISD, and Zn(II)-5BrU-HISD complexes have significant antitumor activity with T/C greater than 125% (where T and C represent mean lifespan of treated mice and control mice respectively). The Mn(II)-5FU-HISD, Co(II)-5FU-HISD, Co(II)-5ClU-HISD, Ni(II)-5ClU-HISD, Ni(II)-5BrU-HISD, and Zn(II)-5ClU-HISD complexes are also effective antitumor agents, with T/C greater than 115%. The complexes that showed effective antitumor action in vivo were also found to inhibit 3H-thymidine incorporation (DNA replication) in Daltons lymphoma cells in vitro.

Synthesis, characterization, and antitumor activity of 5-iodouracil complexes

Complexes of 5-iodouracil (5IU) with Mn(II), Co(II), Cu(II), Zn(II), and Cd(II) ions have been prepared, characterized, and subjected to a screening system for evaluation of antitumor activity against Sarcoma-180 (S-180) and L 929 tumor cells. The complexes were characterized by their elemental analysis, infrared spectra, electronic spectra, magnetic measurements, and powder x-ray diffraction. The antitumor activity results indicate that some complexes have good antitumor activity both in vivo and in vitro against S-180 and L 929 tumor cells.

Transition metal complexes of 5-chlorouracil

SummaryComplexes of 5-chlorouracil (5-ClU) (1) with 3d metal ions were characterized by elemental analysis, various spectroscopic methods (i.r., u.v. spectroscopy) and magnetic susceptibility measurements. The spectral evidence suggest that 5-ClU behaves as bidentate ligand in NiII, CuII, ZnII, and CdII compounds, coordinating through its one carbonyl oxygen and one nitrogen whereas with MnII and CoII it coordinates through the carbonyl oxygen only. The insolubility of the new complexes in organic solvents suggests that these are polymeric except for the CoII complex which is soluble in pyridine. There is probable OH bridging in the MnII and CuII complexes and the 5-ClU may bridge in the rest.

Statistical mechanical theory for discotic liquid crystals Discotic nematic-isotropic transition properties

Abstract A statistical mechanical theory is applied to study the equilibrium properties of discotic nematic liquid crystals. We report the calculation of thermodynamic properties for a model system composed of molecules interacting through angle-dependent pair potentials which can be broken up into rapidly varying short-ranged repulsions and weak long-range attractions. The repulsive interaction is represented by a repulsion between hard oblate ellipsoids of revolution and is a short-range, rapidly-varying, potential. The influence of attractive potentials, represented by dispersion and quadrupole interactions on a variety of thermodynamic properties is analysed. It is found that the thermodynamic properties for the discotic nematic-isotropic transition are highly sensitive to the form of effective one-body orientational perturbation potential. The discontinuity in the transition properties is more pronounced in the case of quadrupole interaction than for anisotropic dispersion interaction. A remarkable s...

Glycogen Accumulation in the Ovarian Follicle of Indian Vespertilionid Bat, Scotophilus heathi during the Period of Delayed Ovulation

Abstract Massive accumulation of glycogen in the follicles of Scotophilus heathi during the period of delayed ovulation was noticed. The follicles which survive for prolonged periods are morphologically specialized. The accumulation of glycogen was noticed in the granulosa cells. The egg cytoplasm, thecal cells and interstitial cells were almost devoid of glycogen. The first sign of a glycogen deposit in the ovary was noticed during the recrudescence phase (October) in late pre-antral follicles. Most of the morphologically healthy late pre-antral and antral follicles showed a positive reaction with PAS and Best carmine from October to early February. Morphologically atretic follicles showed only a mild glycogen accumulation. Little or no glycogen accumulation was noticed in some of the healthy late-antral follicles before ovulation during late February and early March. HCG-induced antral follicles during quiescence also did not show any accumulation of glycogen. The study suggests that glycogen laden follicles are not suitable for ovulation and may be the reason for the occurrence of delayed ovulation in S. heathi.

Complexes of some trace metal ions with 5-fluorouracil

Abstract The preparation of 5-fluorouracil complexes with Mn(II), Co(II), Ni(II), Cu(II), Zn(II) and Cd(II) are reported. The new complexes have been characterised by elemental analysis, solid-state infrared, electronic spectra and magnetic measurements. These measurements suggest that the ligand is bonded to the metal ions through the carbonyl group, behaving as a mono- dentate ligand. On the basis of the ν(OH)bending frequencies and the insolubility of the complexes in common organic solvents, polymeric structures have been proposed for the complexes, with bridging through OH groups. Mn(II), Zn(II) and Cd(II) form four-coordinated complexes, while six coordination numbers have been suggested for Co(II), Ni(II) and Cu(II).

Expression and cellular pattern of relaxin mRNA in porcine corpora lutea during pregnancy

We developed an in situ hybridization method for detecting relaxin mRNA in the porcine corpus luteum (CL) by employing a non-radioactive probe and microwave fixation. We subsequently examined the expression and cellular patterns of relaxin mRNA in the CL during pregnancy and then evaluated whether relaxin mRNA was a factor limiting hormone production by the CL. Digoxigenin (DIG)-labeled RNA probes complementary to porcine relaxin mRNA were produced by in vitro transcription. The specificity was validated by showing, by Northern analysis, that the anti-sense probe hybridized to a 1.0-kb relaxin transcript in the CL. Microwave fixation (2-min irradiation in a conventional microwave oven) combined with DIG-labeled cRNA probes allowed precise and reliable analysis of relaxin mRNA, with superior retention of the mRNA and a higher resolving power. Application of this method to the porcine CL during pregnancy demonstrated that the relaxin mRNA level per cell and the percentage of mRNA-expressing cells increased as gestation progressed, with a marked decline near term. Northern analysis revealed the cellular pattern of relaxin mRNA localization, showing that the increase of relaxin mRNA with advancing pregnancy was attributable to an increase of both the cellular mRNA level and the percentage of mRNA-expressing cells. The present findings, taken together with known relaxin levels in the CL, reveal that changes of relaxin mRNA are correlated with changes of the hormone in the CL during pregnancy, suggesting that the relaxin level is determined by the amount of mRNA available for translation.

Synthesis and Spectroscopic Studies of Simple and Mixed Complexes of Nickel(II) and Zinc(II) with an AZO Dye

Abstract New simple and mixed complexes of 1-(2-pyridylazo)-2-naphthol (PAN) and 1,10-phenanthroline (phen) or 2,2′-bipyridyl (bipy) with nickel(II) and zinc(II) were synthesized and characterized by elemental analyses, conductivity, infrared, electronic spectra, room temperature magnetic measurements, and X-ray diffraction studies. The I. R. data suggest the coordination of PAN through oxygen and (pyridine) nitrogen, whereas phen and bipy coordinate through the pyridine nitrogens. The UV-Vis. spectra along with magnetic measurements favor a tetrahedral geometry for the complexes. The podwer X-ray diffraction studies indicate tetragonal symmetry for all these complexes except for Ni(II)-PAN-phen, which has orthorhombic symmetry. aPresent address: School of Materials Science and Technology, I. T, B.H.U., Varanasi - 221 005, India Referee I: C. E. Barnes Referee II: T. C. Strekas

Oxovanadium(IV) and Dioxouranium(VI) Complexes of Azo Dyes

Abstract Oxovanadium(IV) and dioxouranium(VI) complexes of 1-(2-pyridylazo)-2-naphthol (PAN) and 4-(2-pyridylazo) resorcinol (PAR) have been prepared and characterised by elemental analyses, various physico-chemical methods and magnetic measurements. The I. R. observations suggest that PAN is coordinated through oxygen and (pyridine) nitrogen, whereas PAR is coordinated through (pyridine) nitrogen and the ortho-hydroxyl group. The spectral-studies suggest that oxovanadium(IV) complexes have the coordination number five and dioxouranium(Vl) complexes have the coordination number six for the cations.

Perturbation theory for non-axial molecular fluids

The thermodynamic perturbation theory in which all angle-dependent interactions are considered as a perturbation of the central potential is applied to study the equilibrium properties of a fluid composed of non-axial molecules. The influence of a large number of anisotropic pair and three-body non-additive interactions have been taken into account. Using the same set of force parameters the calculation is made for gaseous pressure second and third virial coefficients and liquid phase thermodynamic properties (Helmholtz free-energy, configurational energy, pressure and entropy). It is shown that the non-axial approximation is an improvement over the axial one. Excellent agreement between theory and experiment is obtained for ethylene.