The development of potent proteasome inhibitors based on the stereochemical diversity-oriented strategy using a conformationally rigid cyclopropane structure was investigated. Thus, a series of stereo- and regioisomeric analogs of belactosin A (2), a cyclopropane amino acid (methanoamino acid)-containing tripeptidic proteasome inhibitor, were designed, in which the central cyclopropane amino ac...

Protectin D1, neuroprotectin D1 when generated by neural cells, is a member of a new family of bioactive products generated from docosahexaenoic acid. The complete stereochemistry of protectin D1 (10,17S-docosatriene), namely, chirality of the carbon-10 alcohol and geometry of the conjugated triene, required for bioactivity remained to be assigned. To this end, protectin D1/neuroprotectin D1 (P...

ras proto-oncogenes with a cyclobutane-type thymine photodimer (cis-syn or trans-syn isomer) were constructed by replacement of a portion of the gene with a chemically synthesized fragment. When the genes were transfected by the calcium phosphate method into mouse NIH3T3 cells, they induced focus-formation, indicating that both photoproducts were mutagenic in mammalian cells. Sequence analysis ...

The geometric specificity of three different alcohol dehydrogenases (alcohol:NAD+ oxidoreductase, EC 1.1.1.1) (from yeast, from horse liver, and from Leuconostoc mesenteroides) in the reduction of trans- and cis-cinnamaldehydes has been investigated. All three enzymes display a remarkable trans specificity: they react with the trans isomer 7 to 647 times faster than with its cis counterpart. Ex...

Using an high-performance liquid chromatography (HPLC) system and UV detection, a simple and precise analytical procedure was developed to quantify levels of cis and trans isomer of cefprozil diastereomers in human plasma. Cefprozil was extracted from plasma samples into 10% perchloric acid. The HPLC system included an acetonitrile-0.05M monopotassium phosphate water (adjust pH to 3.05 with gla...

Context. Among the six atoms of N-containing molecules with formula CH 3 NO, only formamide (H 2 NCHO), most stable structural isomer, has been detected in interstellar medium (ISM). The formaldoxime isomer may be formed, for example, by reaction formaldehyde CO) or methanimine CNH) and hydroxylamine NOH), which are all ISM. lack high accuracy millimeter- submillimeter-wave measurements hinders...

The influence of trans -to-NO ligand (X) on the thermal stability transient side-on coordinated nitrosyl linkage isomer (MS2) is investigated in a series -[RuNOPy 4 X](PF 6 ) 2 (X = F − (RuF), Cl (RuCl), Br (RuBr) and OH (RuOH)) compounds.

The effect of antacid on the bioavailability of cefprozil was investigated in a two-way crossover study. Eight healthy male subjects received a single 500-mg oral dose of cefprozil with and without coadministration of 30 ml of an antacid suspension containing magnesium hydroxide and aluminum hydroxide (Maalox). Cefprozil consists of cis and trans isomers in an approximate 90:10 ratio. When cefp...

The thermodynamic preference for the trans isomer of prolyl peptide bonds arises almost entirely from enthalpy in aqueous buffer and in toluene.

BACKGROUND Some experimental studies on conjugated linoleic acid (CLA) and insulin regulation suggested that CLA could be associated with risk of diabetes, but epidemiologic studies are lacking. OBJECTIVE The aim of the study was to test whether the amount of CLA in adipose tissue is associated with risk of diabetes. DESIGN A cross-sectional design was used to test the study hypothesis in 2...