1990 1 4 4 0
THERMODYNAMIC STUDIES OF THE INTERACTION OF SODIUM N-DODECYL, SULPHATE WITH CALF - THYMUS WISTONE H3 - 2 2 The binding of Sodium n-dodecyl sulphate (SDS) to histone H3 was studied in the pH range 3.2-10 by equilibrium dialysis at 27? and 3 7 ?c .T he binding data have been used to obtain the Gibbs free energy of interaction using a theoretical model of the Wyman binding potential; and the enthalpy of interaction from the temperature dependence of theequilibriumconstantsfronr theVan't Hoff re1ation.The enthalpy of interaction of H3 and SDS is exothermic in some buffer solutions which is in marked contrast to other histone - SDS complexes, The entropy of initial interaction of H3 and SDS is negative in some other buffer solutions with increasing binding of SDS, the entropy becomes positive. 1 - 0 0
THE INFLUENCE OF CHARGE DENSITY ON THE INTERACTION BETWEEN SODIUM NDUDECYL SULPHATE (SDS) WITH H1 - 2 2 The binding data for the interaction of SDS with HI, in aqueous solution at various ionic strengths have been measured by equlibrium dialysis, and investigated spectroscapicaliy. The effect of charge density on the interaction is shown to be of considerable interest. The presence of NaCl causes conformational changes on the structure of HI; whereas this phenomena seems to become more intensified upon contact with SDS. The existence and the importance of charge density which cause additional forces in the macromolecular structures at identical ionic strengths is reported 1 - 0 0
A QUANTUM CHEMICAL STUDY OF STRUCTURE -ACTIVITY RELATIONSHIPS OF DIHYDROPYRIDINE CALCIUM ANTAGONISTS - 2 2 Quantum chemical (MNDo)caleulations have beenused toelucidate the molecular properties and structure - activity relationships of dihydropyridine (DHP) type calcium antagonists. There is a good corielation between the net atomic charges on various atoms of the 4 - phenyl ring of dihydropyridines and pharmacological activity. .Also, activity decreases with increasing free rotation of the phenyl ring. These results indicate that the binding of the 4 - phenyl ring to a rigid part of the receptor plays an important part in the activity of DHP calcium antagonists 1 - 0 0
SPECTROPHOTOMETRIC DETERMI NATION OF OSMIUM (VIII) WITH 1-HYDROXY 2- PYRIDINE - THIONE (SODIUM SALT) AS A REAGENT - 2 2 A spectrophotometric study of osmium (VIII) complex of 1-hydroxy 2- pyridine thione (HPT) is presented. A red-violet complex, 0 s (HPT) is formed in a highly acidic solution, and shows maximum absorbance at 500 nm with molar absorptivity of 5.12 x 101. mol . cm . Beer's law is obeyed in the range of 3-60 ppm. Sandel's sensitivity of the method is 0.37 ?g.cm per0.001 ab sorbance unit. V (V), Pt (IV), Cu (II), Sn (IV), Cr (VI), and NO . interference. To overcome the interference and improve the selectivity, the 0 s (VIII) as OsO isextracted inCC1 and theextracted 0s (VIII) is converted to the complex and measured spectrophotometrically. This method reduces the number of interferences to V(V), Pt (IV), and NO -. The method offers the advantages of simplicity, speed and high precision. A spot test for the detection of traces of osmium is also presented 1 - 0 0
SYNTHESIS AND SPECTROSCOPIC STUDIES OF THIOCYANATO -DERIVATIVES OF CU-Mo-S CLUSTERS - 2 2 The complexes [MoS (CUNCS) ] w hen x = 2,3,4 and [MoOS , (CUNCS) ] when y = 2, 3 have been prepared by the reaction of CuSCN with [P(C H ) ] [MoS ] or [P(C H ) ] [MOOS ] in dry degassed acetone or DMFsolution and recrystallized from dichloromethane, the attempted preparation of [MoS (AgSCN) ] and [MOOS (AgSCN) ] failed. The Raman, IR, UV/VIS, C-nmr and Mo-nmr spectra of the complexes are discussed 1 - 0 0
REACTION OF TRIMETHYLCHLOROSILANE WITH EPOXYKETONES IN THE PRESENCE OF MAGNESIUM - 2 2 Mixture of the trimethylchlorosilane, magnesium and hexamethylphosphorictriamid, HMPT, react with epoxyketones to produce tetrasiliciated compounds, which are the results of the addition of two trimethylsilyl (TMS) groups to the carbonyl function and two TMS groups to the expoxide cycle. After elimination of (Me Si) O siliciated enoxysilanes are obtained which under acidic conditions gives B - siliciated ketones 1 - 0 0
THE SYNTHESES OF 1- [[2- AMINO -1 - (HYDROXYMETHYL) ETHOXY] METHYL] URACIL AND 1, 3-BIS (2- HALOETHOXYMETHYL) PYRIMIDINE - 2 2 The syntheses of the title compounds are described. 1- [[2- Amino -1 - (hydroxymethyl) ethoxy] methyl] uracil exhibitslittleactivity against herpesviruses (HSV) in vivo 1 - 0 0
DEUTERIUM STUDIES IN THE DISPROPORTIONATION OF THIOXANTHYLIUM SALTS - 2 2 Deuterium labelling is used to show that the disproportionation of thioxanthylium salts involve transfer of a hydride, (deuteride) ion from the9-positionof one molecule of the compound, as its hydro], to the 9 - position of another molecule in the cation form 1 - 0 0
SELENIUM HETEROCYCLES XXXX [I] SYNTHESES OF 4- (2-PYRAZINYL) - 1, 2, 3: SELENADIAZOLE AND 4- (2-PYRAZILYL)' - l,2,3- THIADIAZOLE - 2 2 Reaction of thionyl chloride with 2-acetyl-1- benzenesulfonylpyrrole semicarbazone (6 c) gave 4 - (1- benzenesulfonyl-2 - pyrrolyl) - 1, 2, 3 -thiadiazole (lc). Selenium dioxide oxidation of 2-acetylpyrazine semicarbazone (10) in acetic acid afforded 4- (2-pyrazinyl) - 1, 2, 3- selenadiazole (4). Reaction of thionyl chloride with compound 10 gave 4- (2-pyrazinyl) - 1, 2, 3- thiadiazole (3). Base catalized decomposition of 4 afforded the cis-fulvene 13. Similarly, reaction of 3 with a base gave the corresponding cis-fulvene 11. Heating compounds 11 or 13 gave respectively the corresponding trans isomers 12 or 14. 1 - 0 0
A CHARACTERIZATION OF EXTREMELY AMENABLE SEMIGROUPS - 2 2 Let S be a discrete semigroup, m (S) the space of all bounded real functions on S with the usualsupremum norm. Let Acm (S) be a uniformly closed left invariant subalgebra of m (S) with 1 c A. We say that A is extremely left amenable if there isamultiplicative left invariant meanon A. Let P = {h ?A: h =|g-1,g | forsome g ?A, s ?S}. It isshown that . A is extremely left amenable if and only if there is a mean ? on A such that ?(PA) = 0. 1 - 0 0
BAYES ESTIMATION USING A LINEX LOSS FUNCTION - 2 2 This paper considers estimation of normal mean ? when the variance is unknown, using the LINEX loss function. The unique Bayes estimate of ? is obtained when the precision parameter has an Inverse Gaussian prior density 1 - 0 0
THE POMERON IN A MODIFIED MU LTIPERIPHERAL MODEL - 2 2 There have been many attempts [I-31 to produce correct pomeron by putting the nparticle production amplitude expht, in the unitarity integral equation. It was found that for reasonable values of h one could not get the right picture of the slope of the pomeron as a function of energy S4 .W e show that theinterference termsin the unitary equation does not improve the slope either. However, a modified multiperipheral model predicts a correct pomerpn 1 - 0 0