Design and synthesis of novel p38α MAP kinase inhibitors: discovery of pyrazole-benzyl ureas bearing 2-molpholinopyrimidine moiety

The discovery that pyrazole-benzyl urea derivatives bearing a 2-molpholinopyrimidine moiety are novel p38α inhibitors is described. A comparative view of the binding modes of SB-203580 and BIRB-796 by structural alignment of two X-ray co-crystal structures was utilized to identify this novel series. Modification of the benzyl group led to compound 2b, a highly potent p38α inhibitor. In in vivo studies, 2b inhibited the production of tumor necrosis factor-alpha in lipopolysaccharide-treated mouse in a dose-dependent manner. Furthermore, the results of a 5-day repeated oral dose toxicity study suggest that 2b has low hepatotoxicity.     

Discovery of 4-oxo-6-((pyrimidin-2-ylthio)methyl)-4H-pyran-3-yl 4-nitrobenzoate (ML221) as a functional antagonist of the apelin (APJ) receptor

The recently discovered apelin/APJ system has emerged as a critical mediator of cardiovascular homeostasis and is associated with the pathogenesis of cardiovascular disease. A role for apelin/APJ in energy metabolism and gastrointestinal function has also recently emerged. We disclose the discovery and characterization of 4-oxo-6-((pyrimidin-2-ylthio)methyl)-4H-pyran-3-yl 4-nitrobenzoate (ML221), a potent APJ functional antagonist in cell-based assays that is >37-fold selective over the closely related angiotensin II type 1 (AT1) receptor. ML221 was derived from an HTS of the ～330,600 compound MLSMR collection. This antagonist showed no significant binding activity against 29 other GPCRs, except to the κ-opioid and benzodiazepinone receptors (<50/<70%I at 10 μM). The synthetic methodology, development of structure–activity relationship (SAR), and initial in vitro pharmacologic characterization are also presented.     

Improvements in ethanol production from xylose by mating recombinant xylose-fermenting Saccharomyces cerevisiae strains

To improve the ability of recombinant Saccharomyces cerevisiae strains to utilize the hemicellulose components of lignocellulosic feedstocks, the efficiency of xylose conversion to ethanol needs to be increased. In the present study, xylose-fermenting, haploid, yeast cells of the opposite mating type were hybridized to produce a diploid strain harboring two sets of xylose-assimilating genes encoding xylose reductase, xylitol dehydrogenase, and xylulokinase. The hybrid strain MN8140XX showed a 1.3- and 1.9-fold improvement in ethanol production compared to its parent strains MT8-1X405 and NBRC1440X, respectively. The rate of xylose consumption and ethanol production was also improved by the hybridization. This study revealed that the resulting improvements in fermentation ability arose due to chromosome doubling as well as the increase in the copy number of xylose assimilation genes. Moreover, compared to the parent strain, the MN8140XX strain exhibited higher ethanol production under elevated temperatures (38 °C) and acidic conditions (pH 3.8). Thus, the simple hybridization technique facilitated an increase in the xylose fermentation activity.     

Production of quorum-sensing-related signal molecules by epiphytic bacteria inhabiting wheat heads

The production of quorum-sensing-related signal molecules (QSRMs) among culturable bacteria comprising the community on wheat heads was investigated. The taxonomic position of 186 bacterial isolates obtained from ten heads was inferred based on 16S rRNA gene sequences, and their QSRM production was determined using two bioreporter strains of N-acylhomoserine lactones. Approximately 33% of isolates produced QSRMs, though the proportion of QSRM-producing isolates on a wheat head was significantly negatively correlated with population size. Most of the producing isolates were Pantoea species, most commonly Pantoea ananatis. Furthermore, the proportion of Pantoea ananatis that produced QSRMs was significantly negatively correlated with the number of bacterial genera (community richness) on each head. Finally, community richness was positively correlated with population size. Qualitative analysis using thin-layer-chromatography revealed that the QSRMs of Pantoea isolates were composed of at least two compounds. This is the first report indicating that Pantoea ananatis isolates inhabiting wheat heads are capable of producing QSRMs. QSRM production by Pantoea spp. may contribute to the predominance of this genus on wheat heads, particularly at relatively low population densities and community diversity.     

Cyclopentenosine, major trifunctional crosslinking amino acid isolated from acid hydrolysate of elastin

Young male rats were sacrificed either at rest or immediately after a single bout of swimming lasting either 5 or 8 h. Mitochondrial population, obtained by centrifugation (10,000g for 10 min) from liver homogenates freed from debris and nuclei, was resolved by differential centrifugation into three fractions. Homogenates and mitochondrial preparations were examined for their protein content, oxidative capacity (by cytochrome oxidase activity), peroxidative processes (by thiobarbituric acid reactive substance and hydroperoxide levels), antioxidant status (by reduced glutathione and vitamin E levels and whole antioxidant capacity), and susceptibility to in vitro oxidative stress. In all groups, the antioxidant level was smaller and oxidative capacity, lipid peroxidation, and susceptibility to oxidants were greater in the heavy mitochondrial fraction. Exercise of shorter duration did not significantly affect most of the parameters; only the resulting homogenate glutathione level and susceptibility to oxidative stress decreased and increased, respectively, compared with control values. In contrast, more prolonged exercise was associated with increased lipid peroxidation and susceptibility to oxidative stress and decreased antioxidant levels in all preparations. The contribution of each fraction to the whole mitochondrial population was also modified in that the heavy fraction decreased and light fractions increased. These results suggest that liver antioxidant defence systems are able to withstand oxidative challenge due to low-intensity exercise of moderate duration. In contrast, the free radical production associated with long-lasting exercise causes oxidative injury in cellular components and in particular induces protein degradation in the heavy mitochondrial fraction characterized by higher susceptibility to oxidative stress.     

Studies of mortality of atomic bomb survivors. Report 13: Solid cancer and noncancer disease mortality: 1950-1997

This continues the series of general reports on mortality in the cohort of atomic bomb survivors followed up by the Radiation Effects Research Foundation. This cohort includes 86,572 people with individual dose estimates, 60% of whom have doses of at least 5 mSv. We consider mortality for solid cancer and for noncancer diseases with 7 additional years of follow-up. There have been 9,335 deaths from solid cancer and 31,881 deaths from noncancer diseases during the 47-year follow-up. Of these, 19% of the solid cancer and 15% of the noncancer deaths occurred during the latest 7 years. We estimate that about 440 (5%) of the solid cancer deaths and 250 (0.8%) of the noncancer deaths were associated with the radiation exposure. The excess solid cancer risks appear to be linear in dose even for doses in the 0 to 150-mSv range. While excess rates for radiation-related cancers increase throughout the study period, a new finding is that relative risks decline with increasing attained age, as well as being highest for those exposed as children as noted previously. A useful representative value is that for those exposed at age 30 the solid cancer risk is elevated by 47% per sievert at age 70. There is no significant city difference in either the relative or absolute excess solid cancer risk. Site-specific analyses highlight the difficulties, and need for caution, in distinguishing between site-specific relative risks. These analyses also provide insight into the difficulties in interpretation and generalization of LSS estimates of age-at-exposure effects. The evidence for radiation effects on noncancer mortality remains strong, with risks elevated by about 14% per sievert during the last 30 years of follow-up. Statistically significant increases are seen for heart disease, stroke, digestive diseases, and respiratory diseases. The noncancer data are consistent with some non-linearity in the dose response owing to the substantial uncertainties in the data. There is no direct evidence of radiation effects for doses less than about 0.5 Sv. While there are no statistically significant variations in noncancer relative risks with age, age at exposure, or sex, the estimated effects are comparable to those seen for cancer. Lifetime risk summaries are used to examine uncertainties of the LSS noncancer disease findings.     

Production of hydrogen peroxide by polyphenols and polyphenol-rich beverages under quasi-physiological conditions

To investigate the ability of the production of H(2)O(2) by polyphenols, we incubated various phenolic compounds and natural polyphenols under a quasi-physiological pH and temperature (pH 7.4, 37 degrees C), and then measured the formation of H(2)O(2) by the ferrous ion oxidation-xylenol orange assay. Pyrocatechol, hydroquinone, pyrogallol, 1,2,4-benzenetriol, and polyphenols such as catechins yielded a significant amount of H(2)O(2). We also examined the effects of a metal chelator, pH, and O(2) on the H(2)O(2)-generating property, and the generation of H(2)O(2) by the polyphenol-rich beverages, green tea, black tea, and coffee, was determined. The features of the H(2)O(2)-generating property of green tea, black tea, and coffee were in good agreement with that of phenolic compounds, suggesting that polyphenols are responsible for the generation of H(2)O(2) in beverages. From the results, the possible significances of the H(2)O(2)-generating property of polyphenols for biological systems are discussed.     

Oxidative deamination by hydrogen peroxide in the presence of metals

Various amines, including lysine residue of bovine serum albumin, were oxidatively deaminated to form the corresponding aldehydes by a H 2 O 2 /Cu 2+ oxidation system at physiological pH and temperature. The resulting aldehydes were measured by high-performance liquid chromatography. We investigated the effects of metal ions, pH, inhibitors, and O 2 on the oxidative deamination of benzylamine by H 2 O 2 . The formation of benzaldehyde was the greatest with Cu 2+ , and catalysis occurred with Co 2+ , VO 2+ , and Fe 3+ . The reaction was greatly accelerated as the pH value rose and was markedly inhibited by EDTA and catalase. Dimethyl sulfoxide and thiourea, which are hydroxyl radical scavengers, were also effective in inhibiting the generation of benzaldehyde, indicating that the reaction is a hydroxyl radical-mediated reaction. Superoxide dismutase greatly stimulated the reaction, probably due to the formation of hydroxyl radicals. O 2 was not required in the oxidation, and instead slightly inhibited the reaction. We also examined several oxidation systems. Ascorbic acid/O 2 /Cu 2+ and hemoglobin/H 2 O 2 systems also converted benzylamine to benzaldehyde. The proposed mechanism of the oxidative deamination by H 2 O 2 /Cu 2+ system is discussed.