We report here the biologically active conformation of acetylcholine when bound to the high-affinity state of the receptor from Torpedo californica. The acetylcholine conformation was determined in the free and bound states by proton NMR two-dimensional nuclear Overhauser effects. In agreement with x-ray crystallographic data, acetylcholine in solution has an extended conformation with an avera...

purpose : to evaluate the therapeutic effect of posterior sub-tenon methyl prednisolone in anterior ischemic optic neuropathy, no class 1 study has shown any conclusive medical or surgical treatment for non-arteritic anterior ischemic optic neuropathy (naion). efficacy of systemic or intravitreal steroids was suggested by some studies. this study was performed to evaluate the efficacy and safet...

an investigation was made to study the residual activity and air- borne effect of pirimiphos- methyl, at 2g a.i./m2 in hut scale trials on different surfaces in kazeroun, and bandar-abbas, south of iran. in kazeroun area, bio-assay contact mortality test with pirimiphos methyl on mud, wood, cement and plaster surfaces, 54 days after hut spraying, decreased from 100% to 46.7%, 61.25%, 36.6% and ...

Methyl-coenzyme M reductase (MCR) catalyzes both the synthesis and anaerobic oxidation of methane (AOM). Its catalytic site contains Ni at core cofactor F430. The ion, in its low-valent Ni(I) state, lights fuse leading to homolysis C–S bond methyl-coenzyme (methyl-SCoM) generate a methyl radical, which abstracts hydrogen atom from coenzyme B (HSCoB) mixed disulfide CoMSSCoB. Direct reversal thi...

A solvent- and halogen-free synthesis of high purity triflate ionic liquids via direct alkylation of organic bases (amines, phosphines or heterocyclic compounds) with methyl and ethyl trifluoromethanesulfonate (methyl and ethyl triflate) has been developed. Cheap and non-toxic dimethyl and diethyl carbonate serve as source for the methyl and ethyl groups in the preparation of methyl and ethyl t...

In the title compound, C(30)H(31)NO(2), the cyclo-hexa-none ring in the naphthalene fused-ring system adopts a half-chair conformation, presumably due to conjugation of the benzene ring. The naphthalene ring system makes dihedral angles of 86.63 (7), 65.15 (8) and 63.18 (8)° with respect to the two methyl-benzene planes and the 1,2-oxazole ring system. Inter-molecular C-H⋯O and C-H⋯N hydrogen b...

N-Benzyloxycarbonyl derivatives of isoglutamine and isoasparagine were coupled with arginine methyl ester through the action of dicyclohexylcarbodiimide. The resulting benzyloxycarbonyl derivatives of isoglutaminylarginine methyl ester and isoasparaginylarginine methyl ester were treated with trypsin for removal of the ester groups and then with porcine pancreatic carboxypeptidase B for liberat...

The title compound, C12H16Cl4, is a derivative of the natural product 1-isopropyl-4-methyl-cyclo-hexa-1,4-diene, and represents a diastereomer with two trans-fused cyclo-propane rings. Both enanti-omers are present in the non-centrosymmetric polar space group Pna21. The central cyclo-hexane ring is planar within 0.02 (1) Å. The C atoms of di-chloro-methyl-ene groups deviate from this plane by 1...

The title compound, C28H52Si8, was synthesized by condensation of two mol-ecules of 1,2,3,4-tetra-kis-(chloro-dimethyl-sil-yl)benzene with lithium. The 3,4-disila-1,2-benzocyclo-butene rings in the centrosymmetric molecule are bridged by 1,1,2,2-tetra-methyl-disilanylene chains with an anti conformation. The benzene rings are deformed by fusion with a 3,4-disilacyclo-butene ring resulting in a ...

Steady-state, transient, and isotopic-exchange studies of dimethyl ether (DME) carbonylation, combined with adsorption and desorption studies of probe molecules and infrared (IR) spectroscopy, were used to identify methyl and acetyl groups as surface intermediates within specific elementary steps involved in the synthesis of methyl acetate from DME–CO mixtures with >99% selectivity on H-zeolite...