5-Phospho-D-arabonic acid

A simple method for the preparation of 5-phospho-d-arabonic acid by oxidation of d-fructose 6-phosphate is described. The significance of such an easily accessible phosphorylated product of the carbohydrate series obtainable in excellent yield is discussed.     

Heat of reaction of polyribo-5-bromocytidylic acid and polyribo-5-methylcytidylic acid with polyriboinosinic acid

This paper describes a calorimetric investigation of the effect of substitution of methyl and bromine groups at the 5-position of the cytosine ring upon the heats of reaction accompanying the formation of the different 1:1 complexes between these polyribocytidylic acid derivatives and poly(rI). The ΔH of reaction to form poly(rBrC) · poly(rI) at 25 and 37 °C was found to be − 7200 and − 7755 cal./mole of base pairs, respectively. This value is about 2 kcal./mole of base pairs greater than that found for poly(rC) · poly(rI); thus, the bromine substituent produces a large enthalpic stabilization. The ΔH's for poly r(C,BrC) copolymers reacting with poly(rI) were found to vary linearly with bromine content over the entire range of copolymer composition, indicating the absence of any interactions depending upon the sequence of bromine-containing residues. The ΔH of reaction to form poly(rMeC) · poly(rI) was found to be about − 6300 cal./mole of base pairs at 25 and 37 °C. This value represents an enthalpic stabilization relative to poly(rC) · poly(rI) of 700 cal./mole of base pairs arising from the presence of the methyl group. These results clearly show that different types of nucleic acid base pairs can have different enthalpies and entropies characterizing their interaction.     

Synthesis of 5'-deoxy-5'-nucleosideacetic acid derivatives

The synthesis of several new 5'-deoxy-5'-nucleosideacetic acid derivatives by the reactions of alkoxycarbonylmethylene triphenylphosphoranes with nucleoside 5'-aldehydes is described.     

Pusillimonas sp. 5HP degrading 5-hydroxypicolinic acid

A bacterial strain 5HP capable of degrading and utilizing 5-hydroxypicolinic acid as the sole source of carbon and energy was isolated from soil. In addition, the isolate 5HP could also utilize 3-hydroxypyridine and 3-cyanopyridine as well as nicotinic, benzoic and p-hydroxybenzoic acids for growth in the basic salt media. On the basis of 16S rRNA gene sequence analysis, the isolate 5HP was shown to belong to the genus Pusillimonas. Both the bioconversion analysis using resting cells and the enzymatic assay showed that the degradation of 5-hydroxypicolinic acid, 3-hydroxypyridine and nicotinic acid was inducible and proceeded via formation of the same metabolite, 2,5-dihydroxypyridine. The activity of a novel enzyme, 5-hydroxypicolinate 2-monooxygenase, was detected in the cell-free extracts prepared from 5-hydroxypicolinate-grown cells. The enzyme was partially purified and was shown to catalyze the oxidative decarboxylation of 5-hydroxypicolinate to 2,5-dihydroxypyridine. The activity of 5-hydroxypicolinate 2-monooxygenase was dependent on O₂, NADH and FAD.     

Microbial conversion of 5-sulfoisophthalic acid into 5-hydroxyisophthalic acid by Ochrobactrum anthropi S9

5-Hydroxyisophthalic acid-producing microorganisms were isolated from enrichment cultures using 5-sulfoisophthalic acid as a sulfur source. One bacterium, Ochrobactrum anthropi S9, had the highest 5-sulfoisophthalic acid-degrading activity, and stoichiometrically formed 5-hydroxyisophthalic acid, a raw material for polymer synthesis. Under optimum culture conditions, 1.3 mM 5-hydroxyisophthalic acid accumulated in the medium by 60 h. The addition of Na₂SO₄, l-methionine or l-cysteine at 2 mM inhibited the conversion of 5-sulfoisophthalic acid. O. anthropi S9 cells converted 5-sulfoisophthalic acid, benzenesulfonic acid, 3-sulfobenzoic acid, 4-aminobenzenesulfonic acid, naphthalene-1-sulfonic acid and naphthalene-2-sulfonic acid into the corresponding hydroxylated compounds.     

Biosynthesis of 5-oxo-6,8,11,14-eicosatetraenoic acid from 5-hydroperoxyeicosatetraenoic acid in the murine macrophage

5-Oxo-6,8,11,14-eicosatetraenoic acid (5-oxo-ETE) is a metabolite of arachidonic acid shown to possess important biological activities within different cell types. In the neutrophil, a specific NADP(+)-dependent dehydrogenase utilizes 5-lipoxygenase-derived 5-hydroxy-6,8,11,14-eicosatetraenoic acid (5(S)-HETE) as the required substrate. In the present study, 5-hydroperoxy-6,8,11,14-eicosatetraenoic acid (5-HpETE), rather than 5-HETE, was found to be the biosynthetic precursor of 5-oxo-ETE in the murine macrophage. The macrophage was not able to convert 5-HETE into 5-oxo-ETE even when preincubated with phorbol ester or with other lipid hydroperoxides. The factor responsible for the conversion of 5-HpETE into 5-oxo-ETE was found predominantly in the cytosolic fraction of the macrophage, with an approximate molecular weight of 50,000-60,000, as assessed by size exclusion chromatography. Formation of 5-oxo-ETE was rapid and the catalytic protein was found to have an apparent K(m) of 5.3 microM for the eicosanoid. Furthermore, the protein could efficiently utilize 5(R,S)-HpETE as substrate and was heat and protease labile. This novel pathway of 5-oxo-ETE biosynthesis in the murine macrophage was consistent with reduction of a 5-hydroperoxy group to an intermediate alkoxy radical that could be subsequently oxidized to the 5-oxo product. Such a mechanism would enable racemic 5-HpETE, derived from free radical oxidation of arachidonic acid, to be efficiently converted into this potent chemotactic eicosanoid.     

Pharmacological activities of fusaric acid (5-butylpicolinic acid).

This review article aims at summarizing research findings on the various pharmacological activities of fusaric acid (5-butylpicolinic acid), a mycotoxin produced by several Fusarium species which commonly infect cereal grains and other agricultural commodities. The actions of the toxin on mammals, birds, arthropods, crustaceans and plants are covered. The effects on mammals are diverse and are apparent in the nervous, cardiovascular and immune systems. Fusaric acid is toxic to some mammalian tumor cell lines.