Synthesis and Identification of a new class of antileukemic agents containing 2-(arylcarboxamide)-(S)-6-amino-4,5,6,7-tetrahydrobenzod]thiazole

Recently we have reported the effect of (S)-6-aryl urea/thiourea substituted-2-amino-4,5,6,7-tetrahydrobenzod]thiazole derivatives as potent anti-leukemic agents. To elucidate further the Structure Activity Relationship (SAR) studies on the anti-leukemic activity of (S)-2,6-diamino-4,5,6,7 tetrahydrobenzod]thiazole moiety, a series of 2-arlycarboxamide substituted-(S)-6-amino-4,5,6,7-tetrahydrobenzod]thiazole were designed, synthesized and evaluated for their anti-leukemic activity by trypan blue exclusion, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), lactate dehydrogenase (LDH) assays and cell cycle analysis. Results suggest that the position, number and bulkiness of the substituent on the phenyl ring of aryl carboxamide moiety at 2nd position of 6-amino-4,5,6,7-tetrhydrobenzod]thiazole play a key role in inhibiting the proliferation of leukemia cells. Compounds with ortho substitution showed poor activity and with meta and para substitution showed good activity. (C) 2010 Elsevier Masson SAS. All rights reserved.

Local variability and base sequence effects in DNA crystal structures.

The importance and usefulness of local doublet parameters in understanding sequence dependent effects has been described for A- and B-DNA oligonucleotide crystal structures. Each of the two sets of local parameters described by us in the NUPARM algorithm, namely the local doublet parameters, calculated with reference to the mean z-axis, and the local helical parameters, calculated with reference to the local helix axis, is sufficient to describe the oligonucleotide structures, with the local helical parameters giving a slightly magnified picture of the variations in the structures. The values of local doublet parameters calculated by NUPARM algorithm are similar to those calculated by NEWHELIX90 program, only if the oligonucleotide fragment is not too distorted. The mean values obtained using all the available data for B-DNA crystals are not significantly different from those obtained when a limited data set is used, consisting only of structures with a data resolution of better than 2.4 A and without any bound drug molecule. Thus the variation observed in the oligonucleotide crystals appears to be independent of the quality of their crystallinity. No strong correlation is seen between any pair of local doublet parameters but the local helical parameters are interrelated by geometric relationships. An interesting feature that emerges from this analysis is that the local rise along the z-axis is highly correlated with the difference in the buckle values of the two basepairs in the doublet, as suggested earlier for the dodecamer structures (Bansal and Bhattacharyya, in Structure & Methods: DNA & RNA, Vol. 3 (Eds., R.H. Sarma and M.H. Sarma), pp. 139-153 (1990)). In fact the local rise values become almost constant for both A- and B-forms, if a correction is applied for the buckling of the basepairs. In B-DNA the AA, AT, TA and GA basepair sequences generally have a smaller local rise (3.25 A) compared to the other sequences (3.4 A) and this seems to be an intrinsic feature of basepair stacking interaction and not related to any other local doublet parameter. The roll angles in B-DNA oligonucleotides have small values (less than +/- 8 degrees), while mean local twist varies from 24 degrees to 45 degrees. The CA/TG doublet sequences show two types of preferred geometries, one with positive roll, small positive slide and reduced twist and another with negative roll, large positive slide and increased twist.(ABSTRACT TRUNCATED AT 400 WORDS)

Biorthogonal series method for Oseen type flows

A biorthogonal series method is developed to solve Oseen type flow problems. The theory leads to a new set of eigenfunctions for a specific class of linear non-selfadjoint operators containing the biharmonic one. These eigenfunctions differ from those given earlier in the literature for the biharmonic operator. The method is applied to the problem of thermocapillary flow in a cylindrical liquid bridge of finite length with axial through flow. Flow and temperature distributions are obtained at leading order of an expansion for small surface tension Reynolds number and Prandtl number. Another related problem considered is that of cylindrical cavity flow. Solutions for both cases are presented in terms of biorthogonal series. The effect of axial through flow on velocity and temperature fields is discussed by numerical evaluation of the truncated analytical series. The presence of axial through flow not only convectively shifts the vortices induced by surface forces in the direction of the through flow, but also moves their centers toward the outer cylindrical boundary. This process can lead to significantly asymmetric flow structures.

Genetic transformation of Brassica nigra by agrobacterium based vector and direct plasmid uptake

Genetic transformation systems have been established for Brassica nigra (cv. IC 257) by using an Agrobacterium binary vector as well as by direct DNA uptake of a plasmid vector. Both the type of vectors carried nptII gene and gus gene. For Agrobacterium mediated transformation, hypocotyl tissue explants were used, and up to 33% of the explants produced calli on selection medium. All of these expressed B-glucuronidase gene on histochemical staining. Protoplasts isolated from hypocotyl tissues of seedlings could be transformed with a plasmid vector by FEG mediated uptake of vector DNA. A number of fertile kanamycin resistant plants were obtained using both the methods, and their transformed nature was confirmed by Southern blot analysis and histochemical staining for GUS. Backcrossed and selfed progenies of these transformed plants showed the presence of npt and gus genes.

Absorption, translocation and metabolism of fluchloralin in groundnut (Arachis hypogaea) and pigweed (Amaranthus viridis)

Root absorption and translocation of [C-14]fluchloralin were determined in groundnut (Arachis hypogaea L.) cv. TMV-2 and pigweed (Amaranthus viridis L.) grown in nutrient solution culture under greenhouse conditions. Root-applied fluchloralin toxicity to groundnut and pigweed was also examined. A growth reduction of 50% occurred in groundnut that received fluchloralin at a concentration of 9.0 mum. Root absorption was similar for both groundnut and pigweed at one day after application (DAA), but groundnut absorbed about twice the amount of fluchloralin during 4 and 8 days of continuous application, compared with pigweed. Groundnut absorbed 25% of the total applied fluchloralin after 8 days. Translocation to leaves from treated roots was low and roots of groundnut contained 80% of the total absorbed C-14, 8 DAA. Contrary to the observations in groundnut, transport from the roots and leaves following root application in pigweed was rapid: 1 and 8 DAA, leaves of pigweed contained 45 and 70% of the total absorbed C-14, respectively. Different patterns of fluchloralin metabolism were observed in pigweed and groundnut. Pigweed metabolized most of the fluchloralin absorbed by roots. The fluchloralin tolerance of pigweed could partially be accounted for by absorption, translocation and metabolism.

Heterogeneous nucleation of pb particles embedded in a Zn matrix

Zinc-10 and 20 wt pct Pb alloys have been rapidly solidified by melt spinning to obtain a very fine scale dispersion of nanometer-sized Pb particles embedded in Zn matrix. The microstructure and crystallography of the Pb particles have been studied using transmission electron microscopy (TEM). Each embedded Pb particle is a single crystal, with a truncated hexagonal biprism shape with the 6/mmm Zn matrix point group symmetry surrounded by and { 0001 á },\text { \text10[`\text1] \text0 },\text and { \text10[`\text1] \text1 }0001 1010 and 1011 facets. The Pb particles solidify with a well-defined orientation relationship with the Zn matrix of ( 0001 )Zn ||(111)Pb\text and\text [ \text11[`\text2] \text0 ]Zn| ||[ 1[`1] 0 ]Pb 0001Zn(111)Pb and 1120Zn110Pb . The melting and solidification behavior of the Pb particle have been studied using differential scanning calorimetry (DSC). The Pb particles solidify with an undercooling of approximately 30 K, by heterogeneous nucleation on the {0001} facets of the surrounding Zn matrix, with an apparent contact angle of 23 deg.

Chloroplastic glutamine synthetase from normal and water stressed safflower (Carthamus tinctorius L.) leaves

The chloroplastic isoform of glutamine synthetase (GS(2), EC 6.3.1.2) from normal and water stressed safflower (Carthamus tinctorius L. cv.A-300) leaves has been purified to apparent electrophoretic homogeneity by a procedure involving anion-exchange, hydrophobic and size-exclusion chromatography followed by electroelution of the protein from preparative polyacrylamide gels. The observed molecular weight of the native protein varied from 305-330 kDa depending on the sizing column employed. The native protein is composed of 44 kDa subunits. Under conditions of saturating ammonium and at ATP levels of 0.1-10 mM, double-reciprocal plots with respect to glutamate are biphasic and concave downward at high concentrations of the varied substrate for normal enzyme but are linear for enzyme from water-stressed plants. Under subsaturating ATP levels, K-Glu is over 18-fold lower for enzyme from stressed leaves. The K-m, (ATP) varies with Mg2+ levels in the assay mixture. Double-reciprocal plots of initial velocity with respect to ATP at changing fixed levels of NH4+ are linear for normal enzyme but are curved upwards for enzyme from stressed leaves. Initial velocity data of 1/v vs. 1/ammonium for the enzyme from both the sources are non-linear (curved upwards) when ATP is saturating. At subsaturating ATP levels, the data are linear for normal enzyme but are still non-linear for the enzyme from stressed leaves. The results obtained suggest positively cooperative binding of NH4+ A V-max(/2) value of 3.6 mM for Mg2+ was obtained at 5 mM ATP. The isoelectric point of the native protein from normal and stressed leaves was determined to be, respectively, 5.6 and 6.1. The mixed competitive and competitive inhibitors, methionine sulfoximine and ADP and K-i values of 0.086 mM (0.017 for the enzyme from stressed leaves) and 2.15 mM (1.70 for the enzyme from stressed leaves), respectively. Enzyme from stressed leaves is not inhibited by 5 mM proline. The observed kinetic constants of GS(2) from normal and water stressed safflower seedlings are discussed in relation to the known water-stress tolerance of this crop plant.

Waveform synthesis using Walsh functions International Journal of Electronics

A software and a microprocessor based hardware for waveform synthesis using Walsh functions are described. The software is based on Walsh function generation using Hadamard matrices and on the truncated Walsh series expansion for the waveform to be synthesized. The hardware employs six microprocessor controlled programmable Walsh function generators (PWFGs) for generating the first six non-vanishing terms of the truncated Walsh series. Improved approximation to a given waveform may be achieved by employing additional PWFGs.

First total synthesis of (±)-myltayl-4(12)-ene and single-crystal X-ray structure of exo-12-normyltaylan-4-yl 4-nitrobenzoate

The total synthesis of the unusual sesquiterpene (+/-)-myltayl-4(12)-ene 3 starting from the readily available cyclogeraniol 5 and the single-crystal X-ray structure of the 4-nitrobenzoate 12 of the noralcohol 11 are described.

In vivo and in vitro studies on the differential role of luteinizing hormone and follicle-stimulating hormone in regulating follicular function in the bonnet monkey (Macaca radiata) using specific gonadotropin antibodies

Although a distinct need for FSH in the regulation of follicular maturation in the primate is well recognized, it is not clear how FSH controls the functionality of different cellular compartments of the follicle. It is also not evident whether there is a requirement for LH in follicular maturation in the primate. In the first part of the present study, female bonnet monkeys were administered a well-characterized ovine (o) LH antiserum to neutralize endogenous monkey LH for different periods during the follicular phase, and the effect on the overall follicular maturation process was assessed by analyzing serum estrogen (E) and progesterone (P) profiles. Neither continuous LH deprivation from Day 8 of the cycle nor deprivation of LH on any one day between Days 6 and 10 had a significant effect on serum E and P profiles and the follicular maturation process. The period for which the antiserum was effective was dependent upon the dose injected; 1 ml of the antiserum given on Day 8 blocked ovulation but not follicular maturation. To assess the effect of deprivation of LH/FSH at the cellular level, animals were deprived in vivo of LH (on Days 8 and 9 of the cycle) or of FSH (on Day 6 of the cycle) by injection of highly characterized hCG and ovine (o) FSH antisera, respectively; the in vitro responsiveness of granulosa and thecal cells isolated on Day 10 from these animals was then determined.(ABSTRACT TRUNCATED AT 250 WORDS)

Thermodynamic and structural consequences of changing a sulfur atom to a methylene group in the M13Nle mutation in ribonuclease-S

Two fragments of pancreatic ribonuclease A, a truncated version of S-peptide (residues 1-15) and S-protein (residues 21-124), combine to give a catalytically active complex. We have substituted the wild-type residue at position 13, methionine (Met), with norleucine (Nle), where the only covalent change is the replacement of the sulfur atom with a methylene group. The thermodynamic parameters associated with the binding of this variant to S-protein, determined by titration calorimetry in the temperature range 10-40 degrees C, are reported and compared to values previously reported [Varadarajan, R., Connelly, P. R., Sturtevant, J. M., & Richards, F. M. (1992) Biochemistry 31, 1421-1426] for other position 13 analogs. The differences in the free energy and enthalpy of binding between the Met and Nle peptides are 0.6 and 7.9 kcal/mol at 25 degrees C, respectively. These differences are slightly larger than, but comparable to, the differences in the values for the Met/Ile and Met/Leu pairs. The structure of the mutant complex was determined to 1.85 Angstrom resolution and refined to an R-factor of 17.4% The structures of mutant and wild-type complexes are practically identical although the Nle side chain has a significantly higher average B-factor than the corresponding Met side chain. In contrast, the B-factors of the atoms of the cage of residues surrounding position 13 are all somewhat lower in the Nle variant than in the Met wild-type. Thus, the large differences in the binding enthalpy appear to reside entirely in the difference in chemical properties or dynamic behavior of the -S- and -CH2- groups and not in differences in the geometry of the side chains or the internal cavity surface. In addition, a novel method of obtaining protein stability data by means of isothermal titration calorimetry is introduced.

A note on the choice of interfacial friction angle

Estimates of interfacial friction angle (delta) are necessary for the design of retaining structures and deep foundations, Recommendations in the literature regarding delta values are often contradictory and are therefore not easy to apply in geotechnical design, A critical examination of past studies in terms of data generation techniques used and conclusions drawn indicates that two distinctly different test procedures/techniques have been evolved. The interfacial situation in practice can also be categorized into two broad types, These two types of interface problems in geotechnical engineering are (a) the structure is placed on the free surface of prepared fill (type A situation) and (b) the fill is placed against the material surface which functions as a confined boundary (type B situation), The friction angle delta depends on the surface roughness of the construction material, But in the type A situation, it is independent of density and its limiting maximum value (delta(lim)) is the critical state friction angle phi(cv). In the type B situation, it is dependent on density of the fill and its limiting maximum value is the peak angle of internal friction phi(p) of the fill.

Expression of the Japanese encephalitis virus NS3 and NS2b proteins as glutathione S-transferase fusions

Flaviviruses generate their structural and nonstructural proteins by proteolytic processing of a single large polyprotein precursor. These proteolytic events are brought about both by host cell signalase and a virally encoded protease. The virally encoded proteolytic activity has been shown to reside within the nonstructural protein 3 (NS3) and requires the product of the nonstructural 2b (NS2b) gene. In order to obtain sufficient quantities of pure NS2b and NS3 proteins for kinetic analysis, we have expressed both these proteins in recombinant systems as fusions to glutathione S-transferase (GST). The fusion constructs were driven by the strong bacteriophage T7 promoter. Transfection of these constructs into the African green monkey kidney cell line CV-1 previously infected with a recombinant vaccinia virus expressing the T7 RNA polymerase resulted in synthesis of the fusion proteins. Both the fusion proteins could be purified to homogeneity in a single step using a glutathione agarose affinity matrix.