Optimization by energy minimization of stable complexes occurring along the pathway of hydrolysis of benzylpenicillin and cephalosporin C by the Streptomyces albus G ,-lactamase has highlighted a proton shuttle that may explain the catalytic mechanism of the /J-lactamases of class A. Five residues, S70, S130, N 132, T235 and A237, are involved in ligand binding. The y-OH group of T235 and, in t...

The chromophore of fluorescent proteins, including the green fluorescent protein (GFP), contains a highly conjugated imidazolidinone ring. In many fluorescent proteins, the carbonyl group of the imidazolidinone ring engages in a hydrogen bond with the side chain of an arginine residue. Prior studies have indicated that such an electrophilic carbonyl group in a protein often accepts electron den...

A series of 5alpha-androst-3-enes and 3alpha,4alpha-epoxy-5alpha-androstanes were synthesized and tested for their abilities to inhibit aromatase in human placental microsomes. In these series the original C-17 carbonyl group was replaced by hydroxyl, acetyl and hydroxyimine groups. Inhibition kinetic analysis on the most potent steroid of these series revealed that it inhibits the enzyme in a ...

In the title compound, C(22)H(19)NO, the 2,3-dimethyl-anilinic group is planar with an r.m.s. deviation of 0.0226 Å. The phenyl rings with the carbonyl and imine substituents are also planar with r.m.s. deviations of 0.0019 and 0.0048 Å, respectively. These phenyl rings are oriented at dihedral angles of 74.70 (5) and 79.43 (5)°, respectively, with the 2,3-dimethyl-anilinic group, whereas the d...

Hexaamminecobalt(II) bis-[tetra-carbonyl-cobaltate(-I)], [Co(NH3)6][Co(CO)4]2, was synthesized by reaction of liquid ammonia with Co2(CO)8. The Co(II) atom is coordinated by six ammine ligands. The resulting polyhedron, the hexa-amminecobalt(II) cation, exhibits point group symmetry -3. The Co(-I) atom is coordinated by four carbonyl ligands, leading to a tetra-carbonyl-cobaltate(-I) anion in t...

The title compound, C(19)H(15)NO(5), has an intra-molecular C-H⋯O=C hydrogen bond between a naphthalene H atom and the O atom of the carbonyl group. The inter-planar angle between the naphthalene ring system and the benzene ring is 69.59 (5)°. The dihedral angle between the bridging carbonyl C-C(=O)-C plane and the naphthalene ring system is 61.02 (6)°, which is far larger than that between the...

Anodic oxidation of N-aryl-2,2-diphenylacetamides in acetonitrile undergoes three types of bond-cleavage, one between the benzylic carbon and the carbonyl group, the second between a carbonyl and 'N', and the third between the 'N' atom and aryl group. The selectivity of the cleavage and nature of emerged products is highly dependent on the nature of substituent attached to the aryl group. For e...

In this researchsaccharomyces cerevisiae (baker’s yeast) was used as a cheap, readily accessible, selective, efficient, and green bio-catalyst in a chemo selective reduction of carbonyl group to hydroxyl group. In this green procedure three substrates e.g. (3-(3-nitrophenyl)aziridin-2-yl)-1-phenyl-methanone, pyruvate ester, and 2-acetyl-γ-butyrolactone were r...

The penta-noyl group and the 5-fluoro-uracil moiety of the title compound, C(9)H(11)FN(2)O(3), are essentially coplanar, with the penta-noyl carbonyl group oriented towards the ring CH group and away from the nearer ring carbonyl group. In the crystal structure, two inversion-related mol-ecules form a dimer structure, in which two N-H⋯O hydrogen bonds generate an inter-molecular R(2) (2)(8) rin...

The 3-methyl-butanoyl group and the 5-fluoro-uracil unit of the title compound, C(9)H(11)FN(2)O(3), are essentially coplanar, with the carbonyl group oriented towards the ring CH group and away from the nearer ring carbonyl group. The 3-methyl-butanoyl (C=)C-N-C=O torsion angle of 9.6 (2)° is comparable to that in structurally related compounds. In the solid state, two inversion-related mol-ecu...