an efficient and environmentally friendly procedure for one-pot synthesis of 13-acetyl-9-methyl-11-ox-8-oxa-10,12-diazatricyclo [7.3.1. ] trideca-2,4,6-triene from salicylaldehyde, acetylaceton and urea via biginelli condensation and intramolecular michael-addition by using magnesium bromide as an expensive and easily available catalyst under solvent-free condition is desired. the structural el...

Two types of enantioselective [2 + 2 + 2] cycloadditions of triynes using chiral rhodium catalysts are disclosed. The intramolecular reaction of ortho-aminophenol-tethered triynes provides chiral tripodal compounds. Consecutive interand intramolecular reactions of ortho-phenylene-tethered triynes provide chiral tetraphenylenes.

A fragment of Histidine rich protein II (HRP II 215-236) was investigated by 14N and 17O electric field gradient, EFG, tensor calculations using DFT. This study is intended to explore the differences between 310-helix and α-helix of HRPII both in the gas phase and in solution. To achieve the aims, the 17O and 14N NQR parameters of a fragment of HRPII (215-236) for both structures are calculated...

Density Functional Theory (DFT) calculations have been carried out using a Polarizable Continuum Model (PCM) in an attempt to investigate the electro-molecular properties of branched-chain glucoside (C14C10-D-glucoside) isomers. The results showed that αconfiguration of pyranoside form is thermodynamically the most stable, while the solution should contain much more β...

The presence of intramolecular disulfides in different functional states of the native glucocorticoid receptor in the absence of added oxidants has been examined on nonreducing SDS-polyacrylamide gels. Possible disulfides were trapped by the reaction of thiols in crude receptor solutions with methyl methanethiolsulfonate or iodoacetamide. The presence of diffuse bands at lower molecular weights...

Fragments of the tyrA gene of Escherichia coli, when suitably engineered, can express either the chorismate mutase activity or the prephenate dehydrogenase activity without the other.

The persistent organic pollutant DDT (1,1,1-trichloro-2,2-bis(4-chlorophenyl)ethane) is still indispensable in the fight against malaria, although DDT and related compounds pose toxicological hazards. Technical DDT contains the dichloro congener DDD (1-chloro-4-[2,2-dichloro-1-(4-chlorophenyl)ethyl]benzene) as by-product, but DDD is also formed by reductive degradation of DDT in the environment...

An efficient three-component reaction of dialkyl acetylendicarboxylates and 2-Pyrrolidin in the presence of triphenylphosphine produces dialkyl 2-(2-Pyrrolidin-N-yl)-3-(triphenylphosphanylidene)succinate. These phosphoranes undergo mild intramolecular Wittig reaction to produce dialkyl (E)-2-(4,5-dihydro-3H-pyrrol-2-yl)fumarate in excellent yields.

The phosphoglyceric acid mutases from Baker’s yeast and rabbit skeletal muscle have been crystallized or highly purified in this laboratory, and a comparative study of the kinetic and molecular properties has been conducted (l-3). The phosphoglyceric acid mutases from these two sources as well as from many others (2, 4) are stimulated by catalytic amounts of 2,3-diphosphoglyceric acid, as was o...

Intramolecular cycloadditions between cyclobutadiene and olefins can provide highly functionalized cyclobutene-containing products. The outcome of the reaction depends on the nature of the tether connecting the two reactive partners in the cycloaddition. Electronically unactivated olefins attached to cyclobutadiene through a three-atom, heteroatom-containing tether yield successfully the desire...