Microbial asymmetric hydrolysis of 3-substituted glutaric acid diamides.

AIMS: Micro-organisms were screened for their ability to produce (R)-3-(4-chlorophenyl) glutaric acid monoamide (CGM) from 3-(4-chlorophenyl) glutaric acid diamide (CGD) through stereoselective hydrolysis. (R)-CGM is a useful synthetic intermediate for arbaclofen. METHODS AND RESULTS: Four CGD-assimilating micro-organisms were found to be potential catalysts for (R)-CGM production. Among these micro-organisms, Comamonas sp. KNK3-7 (NITE BP-963) produced (R)-CGM with the highest optical purity [98.7% enantiomeric excess (e.e.)] and was selected as the most promising strain. In addition, Comamonas sp. KNK3-7 could asymmetrically hydrolyse 3-isobutyl glutaric acid diamide (IBD) to produce (R)-3-isobutyl glutaric acid monoamide [(R)-IBM] with high optical purity (>99.0% e.e.). CONCLUSION: The synthesis of a (R)-3-substituted glutaric acid monoamide by desymmetrization of 3-substituted glutaric acid diamide with a micro-organism and an enzyme has not been previously reported. This finding indicates the possibility of the preparation of a variety of optically active 3-substituted glutaric acid monoamides using the amidase from Comamonas sp. KNK3-7. SIGNIFICANCE AND IMPACT OF THE STUDY: The amidase from Comamonas sp. KNK3-7 may be useful for the chemoenzymatic synthesis of various kinds of chiral gamma-aminobutyric acids and may be used in a 'green' process to produce gamma-aminobutyric acids.

[Prevalence of cervical and cerebral atherosclerosis and silent brain infarction in patients with multivessel coronary artery disease].

OBJECTIVES: This clinical study investigated the prevalence of cervical and cerebral atherosclerosis and silent brain infarction in patients with coronary artery disease. METHODS: Cervical and cerebral magnetic resonance angiography(MRA) was performed in 133 patients (98 males, 35 females, mean age 65.3 years) with suspected coronary artery disease, who were divided into a zero- and one-vessel disease group(n = 71) and a two- and three-vessel disease group(n = 62) depending on the number of major coronary branches with 75% or more stenosis. The MRA lesion was defined as more than 50% stenosis. Magnetic resonance imaging(MRI) of the brain was performed within 1 week of MRA in 78 patients without symptomatic stroke and atrial fibrillation. Silent brain infarction on MRI was defined as a focal high intensity area on T2-weighted images larger than 3 mm. RESULTS: The prevalence of MRA lesions was significantly greater in the two- and three-vessel group than in the zero- and one-vessel group(53% vs 14%, p < 0.01). The prevalence of MRI lesion was significantly higher in the two- and three-vessel group than in the zero- and one-vessel group(77% vs 36%, p < 0.01). The size and number of the MRI lesions were also significantly greater in the two- and three-vessel group than in the zero- and one-vessel group(p < 0.01). Neither age nor percentage of male gender was different between the groups. Diabetes mellitus was the common risk factor for coronary artery disease, MRA lesion and MRI lesion. CONCLUSIONS: Cervical and cerebral atherosclerosis and silent brain infarction are frequently observed in patients with multivessel coronary artery disease.

Enhancement of the cardiac beta-adrenergic system at an early diabetic state in spontaneously diabetic Chinese hamsters.

Serial changes in cardiac norepinephrine content and the beta-adrenergic system were investigated during the development of cardiomyopathy in spontaneously diabetic Chinese hamsters (CHAD strain), in comparison to age-matched control Chinese hamsters (CHA) or non-diabetic CHAD hamster littermates. Cardiac norepinephrine content and beta-adrenergic receptor density significantly increased in short-term diabetics. These changes preceded both the development of cardiac hypertrophy and the enhanced response of adenylyl cyclase to isoproterenol plus 5'-guanylylimidodiphosphate [Gpp (NH)p], sodium fluoride, or forskolin stimulation. However, as the diabetic state developed cardiac norepinephrine content, beta-adrenergic receptor density, and adenylyl cyclase activity returned to control levels. The amount of stimulatory or inhibitory guanine nucleotide binding proteins in the diabetic group was similar to those in the control groups. These data suggest that the cardiac beta-adrenergic system is enhanced by the alterations in cardiac sympathetic activity during early diabetes, which are associated with the duration of diabetes rather than with the degree of hypertrophy or strain differences.