In the presence of N(alpha),N(epsilon)-diacetyl-L-Lys-D-Ala-D-Ala as donor, and either D-[(14)C]alanine, [(14)C]-glycine, or meso-[(3)H]diaminopimelic acid as acceptor, the DD carboxypeptidases from Streptomyces R61 and R39 catalyze a transpeptidation reaction with the release of terminal D-alanine from the donor and the formation of either N(alpha),N(epsilon)-diacetyl-L-Lys-D-Ala-D-[(14)C]Ala,...

We describe a fixed-time-interval, kinetic inhibition method, with use of a competitive inhibitor (l) of the urease/glutamate dehydrogenase reaction to increase the "apparent" Michaelis constant by a factor of (1 + [l]lKl). This allows greater flexibility in selecting an appropriate sample dilution for kinetic determinations of urea in serum (i.e., [S]lKm ratio). Nine compounds were screened as...

Apomorphine (APO) is an anti-parkinsonian drug currently in use, which provides relief of Parkinson's symptoms. However, the utility of APO is greatly hampered by its poor bioavailability and rapid metabolism. In the present study, O,O'-diacetyl-apomorphine, a prodrug of apomorphine, was synthesized and its biological activity was examined. The prodrug induced fibroblast growth factor-2 product...

The title co-crystal, C(9)H(9)NO(2)·C(6)H(6)O(2), is composed of one 2,6-diacetyl-pyridine mol-ecule and one resorcinol mol-ecule as the asymmetric unit. In the 2,6-diacetyl-pyridine mol-ecule, the two carbonyl groups are anti-periplanar to the pyridine N atom. In the crystal, the 2,6-diacetyl-pyridine and resorcinol mol-ecules are connected by two O-H⋯O hydrogen bonds, forming planar chains of...

IN RECENT YEARS the automated diacetyl monoxime (DAM) reaction as adapted to the AutoAnalyzer has become the method of choice in many clinical laboratories for the determination of urea in biologic fluids. The method is based on the condensation of urea with diacetyl, the latter usually being liberated from the monoxime in the presence of one of various acid reagents (1, 2). The reaction, howev...

Diacetyl (2,3-butanedione) is a natural ingredient in foodstuffs which is not generally regarded health risk to consumers. Nevertheless, when manufactured for use as a synthetic flavouring/additive in processed foods (e.g. microwave popcorn), it poses a human health threat at the workplace. Its pneumotoxic action consists of inflammation, obstruction and restriction in the distal respiratory tr...

A plasmid-borne diacetyl (acetoin) reductase (butA) from Leuconostoc pseudomesenteroides CHCC2114 was sequenced and cloned. Nucleotide sequence analysis revealed an open reading frame encoding a protein of 257 amino acids which had high identity at the amino acid level to diacetyl (acetoin) reductases reported previously. Downstream of the butA gene of L. pseudomesenteroides, but coding in the ...