Ochratoxin A can be hydrolyzed with a large amount of carboxypeptidase A to yield L-phenylalanine and an isocoumarin carboxylic acid. No hydrolytic effect was found, however, with the liver homogenate or the microsomal fraction of the rat. The toxicity of the hydrolyzate, isocoumarin carboxylic acid, was found to be much lower than that of ochratoxin A (LD50 16.96 ƒÊg/egg) to the chicken embryo...

The complex of porcine pancreatic elastase (PPE) with 7-amino-3-(2-bromoethoxy)-4-chloroisocoumarin, a potent mechanism-based inhibitor, was crystallized and the crystal structure determined at 1.9-A resolution with a final R factor of 17.1%. The unbiased difference Fourier electron density map showed continuous density from O gamma of Ser 195 to the benzoyl carbonyl carbon atom and from N epsi...

The highly regioselective aerobic oxidative cyclization of aromatic, heteroaromatic and alkenyl acids with alkynes in the presence of catalytic amounts of [{RuCl(2)(p-cymene)}(2)], AgSbF(6) and Cu(OAc)(2)·H(2)O providing isocoumarin derivatives was investigated.

A novel ruthenium catalyzed straightforward and efficient synthesis of isocoumarin and α-pyrone derivatives has been accomplished by the decarbonylative addition reaction of anhydrides with alkynes under thermal conditions.

BACKGROUND Urokinase-type plasminogen activator (uPA) plays a major role in extracellular proteolytic events associated with tumor cell growth, migration and angiogenesis. Consequently, uPA is an attractive target for the development of small molecule active site inhibitors. Most of the recent drug development programs aimed at nonpeptidic inhibitors targeted at uPA have focused on arginino mim...

During investigations on the influence of CaBr2 on the secondary metabolism of Lachnum papyraceum, the production of mycorrhizins and lachnumon type antibiotics was strongly inhibited in bromide-containing culture media. Instead, six isocoumarin derivatives, 6-hydroymellein (6), 4-chloro-6-hydroxymellein (7), 4-bromo-6-hydroxymellein (9), 6-methoxymellein (10). 4-chloro-6-methoxymellein (11), a...

Here, we report the draft genome sequence of Bacillus subtilis TP-B0611, which produces the isocoumarin-type compounds bacilosarcin and amicoumacin. The genome encodes three nonribosomal peptide synthetase (NRPS) gene clusters and one hybrid polyketide synthase (PKS)/NRPS gene cluster. The hybrid PKS/NRPS gene cluster was identified to be responsible for the biosynthesis of bacilosarcins and am...