Synthesis,DNA binding,and antimicrobial studies of novel metal complexes containing a pyrazolone derivative Schiff base

A novel series of Co(II), Ni(II), Cu(II), Zn(II), and VO(IV) complexes has been synthesized from the Schiff base derived from 4-[(3,4-dimethoxybenzylidene)amino]-1,5-dimethyl-2-phenyl-1,2-dihydropyrazol-3-one and 1,2-diaminobenzene. Structural features were determined by analytical and spectral techniques. Binding of synthesized complexes with calf thymus DNA (CT DNA) was studied by spectroscopic methods and viscosity measurements. Experimental results indicate that the complexes are able to form adducts with DNA and to distort the double helix by changing the base stacking. Lower DNA affinity of the VO(IV) complex is caused by the change of coordination geometry by the vanadyl ion resulting in a somewhat unfavorable configuration for the DNA binding. Oxidative DNA cleavage activities of the complexes were studied with supercoiled (SC) pUC19 DNA using gel electrophoresis; the mechanism studies revealed that the hydroxyl radical is likely to be the reactive species responsible for the cleavage of pUC19 DNA by the synthesized complexes. The in vitro antimicrobial screening effects of the investigated compounds were monitored by the disc diffusion method. The synthesized Schiff base complexes exhibit higher antimicrobial activity than the respective free Schiff base.     

Preparation of electrodeless discharge lamps for emission studies of uranium isotopes at trace level

A simplified method for preparation of electrodeless discharge lamp for uranium isotopes with specific concerns for ²³²U is described. Micro-gram quantities of solid uranium oxides and aqueous solution of uranium nitrate have been used as a starting material for in situ synthesis of uranium tetraiodide. High temperature iodination reaction is carried out in the presence of inert gas neon. By careful design, the preparation time and surface area of quartz reaction tubes have been reduced considerably. The latter decreases the level of contamination which has a direct bearing on the operational lifetime of the lamps. Incorporation of steps to purify the product from an unwanted material improved the stability of the lamps. The procedure provides a safe and convenient way of handling ²³²U in particular but can be extended in general to any actinides having radioactivity similar to that of freshly separated ²³²U. Characteristic emission of uranium isotopes have been recorded by Fourier Transform Spectrometer to show the satisfactory operation of the lamps as well as their usage for studying emission spectra of the specific isotope.     

Water-promoted unprecedented chemoselective nucleophilic substitution reactions of 1,4-quinones with oxygen nucleophiles in aqueous micelles

Unique nucleophilic substitution and addition reactions of nitrogen and sulfur nucleophiles with 1,4-quinones in aqueous suspension with amines and thiols have recently been demonstrated by us.² However, the reactivity of oxygen nucleophiles toward nucleophilic substitution compared to nitrogen and sulfur nucleophiles ‘on water’ is not facile. An unprecedented economical, green methodology approach using ordinary laundry detergent (LD; washing powder, 0.5 mol %, reusable)/SDS as surfactant ‘in water’ for nucleophilic substitution by oxygen nucleophiles in 1,4-quinones in excellent yields has been demonstrated.     

Stereoselective total synthesis of alkaloid caulophyllumine B using iterative olefin cross-metathesis protocol

Herein we report the first total synthesis of alkaloid caulophyllumine B in 14 steps by an iterative olefin cross-metathesis strategy from l-glutamic acid.     

Stereoselective synthesis of aminocyclitol moieties of trehazolin and trehalostatin via enyne metathesis protocol

Stereoselective and efficient synthesis of respective aminocyclitol moieties 1a and 2a of trehazolin and trehalostatin as hexaacetates 1b and 2b using ring-closing enyne metathesis as the key reaction is described.     

Complementary and Comparative Study on Hypoglycemic and Antihyperglycemic Activity of Various Extracts of Eugenia jambolana Seed, Momordica charantia Fruits, Gymnema sylvestre, and Trigonella foenum graecum Seeds in Rats

In present study, we investigated hypoglycemic and antihyperglycemic potential of five extracts (water, ethanol, methanol, hexane, and chloroform) of four plants (i.e., seeds of Eugenia jambolana, fruits of Momordica charantia, leaves of Gymnema sylvestre, and seeds of Trigonella foenum graecum) alone and/or in combination with glimepiride in rats. Ethanol extract of E. jambolana, water extract of M. charantia, ethanol extract of G. sylvestre, and water extract of T. graecum exhibited highest hypoglycemic and antihyperglycemic activity (most active) in rats among all the extracts, while hexane extracts exhibited least activities. Most active extracts were further studied to dose-dependent (200, 100, and 50 mg/kg body weight (bw)) hypoglycemic and antihyperglycemic effects alone and in combination with glimepiride (20, 10, and 5 mg/kg bw). The combination of most active extracts (200 mg/kg bw) and lower dose of glimepiride (5 mg/kg bw) showed safer and potent hypoglycemic as well as antihyperglycemic activities without creating severe hypoglycemia in normal rats, while higher doses (200 mg/kg bw of most active extracts, and 10 and 20 mg/kg bw of glimepiride) were generated lethal hypoglycemia in normal rats. From this study, it may be concluded that the ethanol extract of E. jambolana seeds, water extract of M. charantia fruits, ethanol extract of G. sylvestre leaves, and water extract of T. graecum seeds have higher hypoglycemic and antihyperglycemic potential and may use as complementary medicine to treat the diabetic population by significantly reducing dose of standard drugs.     

Study of sulfated derivatives of polyhydroxy compounds as inhibitors of blood coagulation

Persulfated derivatives of natural polyhydroxy compounds, such as lignans secoisolariciresinol, and isolariciresinol, flavonoid dihydroquercetin, and myo-inositol, have been synthesized. The ability of these compounds to inhibit the intrinsic pathway of blood coagulation (APTT-test) and to reduce the activity of coagulation factor Xa in the presence of antithrombin(III) has been studied.     

On the directed Full Degree Spanning Tree problem

We study the parameterized complexity of a directed analog of the Full Degree Spanning Tree problem where, given a digraph $D$ and a nonnegative integer $k$, the goal is to construct a spanning out-tree $T$ of $D$ such that at least $k$ vertices in $T$ have the same out-degree as in $D$. We show that this problem is W[1]-hard even on the class of directed acyclic graphs. In the dual version, called Reduced Degree Spanning Tree, one is required to construct a spanning out-tree $T$ such that at most $k$ vertices in $T$ have out-degrees that are different from that in $D$. We show that this problem is fixed-parameter tractable and that it admits a problem kernel with at most $8k$ vertices on strongly connected digraphs and $O\left(k^2\right)$ vertices on general digraphs. We also give an algorithm for this problem on general digraphs with running time $O(5.942^k?n^{O\left(1\right)})$, where $n$ is the number of vertices in the input digraph.     

Parametrizing the lepton mixing matrix in terms of charged lepton corrections

We consider a parametrization of the lepton mixing matrix in which the deviations from maximal atmospheric mixing and vanishing reactor mixing are obtained in terms of small corrections from the charged lepton sector. Relatively large deviations for the reactor mixing angle from zero as indicated by T2K experiment can be obtained in this parametrization. We are able to further reduce the number of complex phases, thus, simplifying the analysis. In addition, we have obtained the sides of unitarity triangles and the vacuum oscillation probabilities in this parametrization. The Jarlskog rephasing invariant measure of CP violation at the leading order has a single phase difference which can be identified as Dirac-type CP violating phase in this parametrization.