Previously we have proposed and provided evidence for a metabolic scheme leading to 3-carbamoyl-2-phenylpropionaldehyde from the antiepileptic drug felbamate. This aldehyde was found to undergo reversible cyclization to form the more stable cyclic carbamate 4-hydroxy-5-phenyl-tetrahydro-1,3-oxazin-2-one or undergo elimination to form 2-phenylpropenal. The cyclic carbamate bears structural simil...

The X-ray crystal structure of carbamoyl phosphate synthetase (CPS) from Escherichia coli revealed the existence of a molecular tunnel that has been proposed to facilitate the translocation of reaction intermediates between remotely located active sites. Five highly conserved glutamate residues, including Glu-25, Glu-383, Glu-577, Glu-604, and Glu-916, are close together in two clusters in the ...

Thiophosphate analogs of adenine nucleotides were used to establish the absolute stereochemistry of nucleotide substrates in the reactions of carbamate kinase (Streptococots faecalis), unadenylylated glutamine synthetase (Escherichia co(i). and carbamoyl-phosphate synthetase (E. coli). :llP NMR ~vvas used to determine that carbamate kinase uses the B isomer of Ado-5’.(2-thioPPP) in the presence...

p-Nitrophenyl N-(2-mercaptophenyl)-N-methylcarbamate cyclizes rapidly at 25' to N-methylbenzothiazolone with release of p-nitrophenol. The pH-rate constant profile is sigmoidal with pK,,, = 8.7. The effective molarity of the neighboring sulfhydryl group is 1.4 X los M in comparison with bimolecular attack of thiols on p-nitrophenyl N-methyl-Nphenylcarbamate. The pH-rate constant profile for cyc...

In the title compound, C16H17NO3S2, the dihedral angles between the O/C/C/S group and the 2H-chromene ring system and the thio-carbamate group are 14.46 (9) and 83.30 (9)°, respectively. The bond-angle sum at the N atom is 360.0°. One of the methyl C atoms lies above the thio-carbamate plane and one lies below it [deviations = 1.264 (3) and -1.147 (3) Å, respectively]. In the crystal, inversion...

The Sn(IV) atom in the title diorganotin dithio-carbamate, [Sn(C(4)H(9))(2)Cl(C(10)H(12)NS(2))], is penta-coordinated by an asymmetrically coordinating dithio-carbamate ligand, a Cl and two C atoms of the Sn-bound tert-butyl groups. The resulting C(2)ClS(2) donor set defines a coordination geometry inter-mediate between square pyramidal and trigonal bipyramidal with a slight tendency towards th...

The use of a bis-urea lithocholamide linker within a guanosine-sterol dimer resulted in formation of large and stable ion channels. The channels were longer-lived than those formed by the corresponding bis-carbamate.

A new strategy for constructing enantiopure acetylenic cyclophanes is described on the basis of one-pot double elimination reaction starting from dialdehydes and bis(sulfoximine)s. In this case, the conventional sulfone protocol affords poorer yields of the desired cyclophanes. Thus, arylene-ethynylene moieties with terminal sulfoximine or formyl functions are linked to binaphthyl cores and the...