High enantioselective Michael addition of malonates to β,γ-unsaturated α-ketoesters catalyzed by bifunctional thioureas

A highly enantioselective Michael addition of malonates to β,γ-unsaturated α-ketoesters was achieved using cinchona alkaloid-derived thioureas as the bifunctional catalyst. The corresponding Michael addition products were obtained in excellent yields (90–99%) and ee values (up to >99% ee) using a quinidine-derived thiourea as the catalyst under neat conditions. The opposite enantiomer may be obtained using a quinine- or cinchonidine-derived thiourea as the catalyst.     

Square eigenfunction approach to the hamiltonian structure for a new hierarchy of nonlinear equations

We deduce the symplectic form for the Hamiltonian structure of a new class of nonlinear equations with the help of square eigenfunctions associated with the corresponding linear problem. The method actually yields two pieces of information simultaneously. One is the structure of the square eigenfunctions, which is of prime importance in the study of the inverse problem. The other is the form of the symplectic structure fixing up the canonical Poisson bracket relation. Finally we discuss some reductions of the initial system and the corresponding change of the Hamiltonian structure and the form of the square eigenfunction.     

Prolongation theory. A new nonlinear Schrödinger equation

We discuss a new kind of nonlinear Schrödinger equation from the viewpoint of prolongation theory. It is shown that the equation possess a Lax pair with a 3 × 3 matrix structure. It is further demonstrated that by a multiple scale perturbation of Zakharovet al. it can be reduced to the usual KdV equation.     

In vitro multiplication in Kaempferia galanga linn

Kaempferia galanga is an important medicinal plant that is facing threat of extinction owing to indiscriminate and unsustainable harvesting in the wild. Conventional breeding is difficult in this plant, and in vitro multiplication is important to conservation and propagation. Leaf and rhizome explants of Kaempferia were aseptically cultured on MS medium with various combinations of indole-3-acetic acid (IAA), benzyl amino purine (BAP), napthalene acetic acid (NAA), 2-4-dichlorophenoxy acetic acid (2,4-D) and kinetin at concentrations ranging from 0.5 to 2.5 mg/L. High-frequency organogenesis and multiple shoot regeneration was induced from rhizome explants on MS medium supplemented with 0.5 mg/L of IAA and 2.5 mg/L of BAP. Rooting was induced in MS medium with 0.5 mg/L of IAA and 2 mg/L of BAP.     

Surface morphology and active sites of TiO<Subscript>2</Subscript> for photoassisted catalysis

The main aim of this work is to discriminate the closely related adsorption and catalytic degradation processes that occur during a photocatalytic reaction. Very high-surface-area TiO₂ and Pd-doped TiO₂ were synthesized by microwave-assisted hydrothermal synthesis and used for degradation of methylene blue as a model pollutant dye. Thorough structural, morphological, and surface analyses of the synthesized catalysts were conducted to investigate key material properties that influence adsorption and catalytic performance. The adsorption capacity of the catalysts was determined by fitting adsorption data using the Langmuir isotherm model, and the photocatalytic activity of the synthesized samples was evaluated by periodically measuring the concentration of methylene blue as it was photocatalytically degraded under ultraviolet (UV) light. The results indicated that noble-metal incorporation compromised adsorption but favored catalytic performance.     

Kac-Moody algebra,nonlocal symmetries,and backlund transformation for KdV equation

Gauge transformation of the Lax eigenfunction through the explicit use of Lie group generators is seen to generate a two-parameter Backlund transformation. Explicit integration of this in two particular cases leads to sech² type and rational solutions starting from the trivial one. A method is indicated to generate infinitesimal transformations aroundu in the sense of Steudel, which in this case leads to a nonlocal structure of transformations.     

The first total synthesis of putaminoxin and determination of its absolute configuration

Asymmetric synthesis of putaminoxin, a phytotoxic macrolide from the cultured dinoflagellate Amphidinium sp., has been accomplished. Absolute configuration of putaminoxin was concluded to be 1 from comparison of the NMR data and [α]_D values of synthetic and natural putaminoxin.     

Evaluation of DNA Binding with Some Selected Hydrazide and Semicarbazide Derivatives

A group of hydrazide and semicarbazide derivatives containing isopropylidene, benzylidene, cyclohexylidene, and phospholidene groups was synthesized and characterized by spectroscopic techniques. These compounds were tested for DNA interaction studies monitored by UV-Vis and IR data as well as molecular docking. Investigations on interactions of these compounds with DNA revealed an intercalative mode of binding between them. It is interesting to note that semicarbazide derivatives with aliphatic substituents showed better DNA binding than the aromatic substituents.