DEUTERIUM TRANSFER ANALYSIS INCLUDING FOOD CHAIN FROM SEAWATER INTO ABALONE.

Tritium is released into the ocean from nuclear facilities located at coastal areas. In addition, tritiated water is decided to be released into the ocean from the Fukushima Dai-ichi Nuclear Power Plant. Although released tritium concentration would be strictly controlled, impact of tritium on the marine products is major concern for the public. In this study, deuterium transfers from seawater into seaweed (ulva) and abalone were measured. In addition, organically bound deuterium (OBD) transfer from ulva into abalone was measured. OBD concentrations in ulva were saturated in 2 weeks and those in abalone were saturated in 6 months. Ulva and abalone were exposed to seawater containing 0.2% (mol-D/mol-H) deuterium. Maximum OBD concentrations in ulva were ~0.1% (mol-D/mol-H) and those in abalone muscle were ~0.035% (mol-D/mol-H). Numerical deuterium transfer model was constructed. Obtained numerical model well represented the OBD-enriched ulva feeding experiment.

Determination of Iodide, Iodate and Total Iodine in Natural Water Samples by HPLC with Amperometric and Spectrophotometric Detection, and Off-line UV Irradiation.

We developed a rapid, simple method for the iodine speciation analysis of water and applied it to natural water samples. Simultaneous determinations of I(-) and IO3(-) were achieved with an HPLC system with amperometric detection for I(-) and spectrophotometric detection after a postcolumn reaction for IO3(-). We determined the I(-) and IO3(-) concentrations in 20-µL water samples within 10 min. Total I concentrations in water samples were determined after the decomposition of organics by off-line UV irradiation for 30 min, followed by reduction to I(-). The analytical conditions were optimized by using test solutions rich in organic matter extracted from soils. We tested the new method with samples of groundwater, spring water, precipitation, soil percolate, stream water, and seawater as well as solutions extracted from soil. The method worked well, although the concentrations of some I species were below detection. This method is suitable for routine speciation analysis, which is important for studies of I behavior in the environment.

Unexpected preference of the E. coli translation system for the ester bond during incorporation of backbone-elongated substrates.

There have been recent advances in the ribosomal synthesis of various molecules composed of nonnatural ribosomal substrates. However, the ribosome has strict limitations on substrates with elongated backbones. Here, we show an unexpected loophole in the E. coli translation system, based on a remarkable disparity in its selectivity for beta-amino/hydroxy acids. We challenged beta-hydroxypropionic acid (beta-HPA), which is less nucleophilic than beta-amino acids but free from protonation, to produce a new repertoire of ribosome-compatible but main-chain-elongated substrates. PAGE analysis and mass-coupled S-tag assays of amber suppression experiments using yeast suppressor tRNAPheCUA confirmed the actual incorporation of beta-HPA into proteins/oligopeptides. We investigated the side-chain effects of beta-HPA and found that the side chain at position alpha and R stereochemistry of the beta-substrate is preferred and even notably enhances the efficiency of incorporation as compared to the parent substrate. These results indicate that the E. coli translation machinery can utilize main-chain-elongated substrates if the pKa of the substrate is appropriately chosen.

Efforts toward codon table engineering: expansion of unnatural substrates acceptable by the E. coli ribosome.

The ribosome catalyzes oligo/polymerization of amino acids. We designed an allowable modification of amino acid backbone, based on the hypothesized mechanism of peptidyl transfer reaction. Nonsense suppression method was used to investigate the acceptability of these substrates in the prokaryotic ribosomal system. The E.coli ribosome showed a restricted tolerance to the backbone modification, especially for main-chain elongation. However, our designed homologous beta-hydroxyalkanoic acid with elongated methylene (backbone) chain-length was revealed to be a possible substrate for the E.coli ribosome.

The novel gluconeogenesis inhibitor FR225654 that originates from Phoma sp. no. 00144. I. Taxonomy, fermentation, isolation and physico-chemical properties.

FR225654, a novel gluconeogenesis inhibitor, was isolated from the culture broth of Phoma sp. No. 00144 and purified by adsorptive resin and reverse-phase column chromatography. This compound is a potent inhibitor of gluconeogenesis and is a promising candidate of anti-diabetic agent.

The novel gluconeogenesis inhibitor FR225654 that originates from Phoma sp. no. 00144. II. Biological activities.

The novel gluconeogenesis inhibitor FR225654, isolated from the culture broth of Phoma sp. No. 00144, has an unique structure that consists of a highly oxygenated trans-decalin ring and a beta-keto-enol, with a characteristic side chain. This compound selectively inhibited gluconeogenesis of rat primary hepatocytes and had hypoglycemic effects in several in vivo mouse models.

FR901512, a novel HMG-CoA reductase inhibitor produced by an agonomycetous fungus no. 14919. II. Biological profiles.

FR901512, a new specific inhibitor of HMG-CoA reductase, was isolated from the culture of an agonomycetous fungus No. 14919. FR901512 inhibited cholesterol synthesis from [14C] acetate in Hep G2 cells with an IC50 of 1.0 nM. An increase of cell surface LDL receptors observed on the FR901512 treated human hepatoma cell line Hep G2 cells. Single oral administration of FR901512 strongly inhibited sterol synthesis in rats. Daily oral administration of FR901512 to beagle dogs decreased plasma cholesterol levels.

FR171456, a novel cholesterol synthesis inhibitor produced by Sporormiella minima No. 15604. I. Taxonomy, fermentation, isolation, physico-chemical properties.

FR171456 and FR173945, novel and potent cholesterol synthesis inhibitors, have been isolated from the fermentation broth of a fungal strain No. 15604. This strain was identified Sporormiella minima from its mycological characteristics. FR171456 and FR173945 strongly inhibited cholesterol synthesis in human hepatoma cell line Hep G2. These compounds also have in vitro antifungal activity against Candida albicans and Aspergillus fumigatus.

FR171456, a novel cholesterol synthesis inhibitor produced by Sporormiella minima No. 15604. II. Biological activities.

Novel cholesterol synthesis inhibitors FR171456 and FR173945 were isolated from the culture broth of Sporormiella minima No. 15604. FR171456 strongly inhibited the cholesterol synthesis and up-regulated the LDL-receptor expression in human hepatoma cell line Hep G2. Single oral administration of FR171456 inhibited in vivo hepatic sterol synthesis in rats. And FR171456 shows a significant serum cholesterol-lowering effect in a cholesterol fed rabbit model.

FR901512, a novel HMG-CoA reductase inhibitor produced by an agonomycetous fungus No. 14919. II. Taxonomy of the producing organism, fermentation, isolation and physico-chemical properties.

Novel compounds FR901512 and FR901516 were isolated from the fermentation broth of agonomycete strain No. 14919. FR901512 and FR901516 possess unique tetralin ring in their structure. These compounds were potent inhibitors of the cholesterol synthesis in human hepatoma cell line Hep G2. FR901512 shows strong 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitory activity with an IC50 value of 0.95 nM.

The novel gluconeogenesis inhibitors FR225659 and related compounds that originate from Helicomyces sp. No. 19353. II. Biological profiles.

The novel gluconeogenesis inhibitor FR225659 and four related compounds were isolated from the cultured broth of a fungal strain No. 19353. These compounds inhibited the glucagon-stimulated gluconeogenesis of rat primary hepatocytes and had hypoglycemic effects in two different in vivo models.

The novel gluconeogenesis inhibitors FR225659 and related compounds that originate from Helicomyces sp. No. 19353. I. Taxonomy, fermentation, isolation and physico-chemical properties.

FR225659 and four related compounds are novel gluconeogenesis inhibitors that consist of a novel acyl-group and three abnormal amino acids. They were isolated from the culture broth of Helicomyces sp. No. 19353 and can be purified by absorptive resin and reverse-phase column chromatography. They are potent inhibitors of gluconeogenesis in primary cultured rat hepatocytes and thus may be useful as anti-diabetic agents.