31297-82-2

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GT1 family glycosyltansferase, Sv0189, from Streptomyces venezuelae ISP5230 (ATCC 10721) was characterized. The recombinantly produced protein Sv0189 possessed UDP-glycosyltransferase activity. Screening, using an assay employing unnatural nitrophenyl glycosides as activated donors, resulted in the discovery of a broad substrate scope with respect to both acceptor molecules and donor sugars. In addition to polyphenols, including anthraquinones, simple aromatics containing primary or secondary alcohols, a variety of complex natural products and synthetic drugs were glucosylated or xylosylated by Sv0189. Regioselectivity was established through the isolation and characterization of glucosylated products. Sv0189 and homologous proteins are widely distributed among Streptomyces species, and their apparent substrate promiscuity reveals potential for their development as biocatalysts for glycodiversification.

Synthesis of glycosyl derivatives of hydroxyanthraquinones (6-10) potentially useful for kidney stone therapy is presented. These compounds were analyzed as inhibitors of calcium oxalate crystals formation as well as substances with the ability of dissolving crystalline calcium oxalate. In addition, the effect of the compounds obtained on real kidney stones was analyzed by ex vivo tests. The tests on L929 and A545 cell lines have shown that the compounds obtained were not cytotoxic.

The invention concerns a novel chromogenic substrate based on Alizarin. The invention also concerns the uses to which this substrate can be put, and a formulation containing such a substrate. It consists therefore of a substrate to detect the presence of an enzyme activity, with the following general formula: in which: the two ketone groups of the central ring can be replaced by one group R11 (in the upper position), and by OH (in the lower position). R1 is a target part or H, and R2 is a target part or H, with at least one out of R1 and R2 being a target part, R3 is H, SO3H, Cl, Br, F, I, NO2, NH2, NR9R10, or an Acylamino Aminoaryl or Aminoacylamino group of the type NHCOX, with X being an Alkyl, Aryl or Aralkyl group or an a-amino acid residue such as Alanine, R4 is H, SO3H, Cl, Br, F, I, NO2, NH2, NR9R10, OH or an Acylamino Aminoaryl or Aminoacylamino group of the type NHCOX, with X being an Alkyl, Aryl or Aralkyl group or an α-amino acid such as Alanine, according to a modification, R3 and R4 form bonds with one another to create a ring with at least five sides, and preferably six sides. R5, R6, R7 and R8 each consist of one of the following atoms or groups of atoms: H, a halogen (particularly Cl or Br), OH, SO3H, or an Alkyl or Alkoxy group, and R9 a R10 are independently a Methyl, Alkyl, Aryl, Aralkyl group, or one (either R9 or R10) is a ring structure (Piperidine, Pyrrolidine, Morpholine, etc.) with the other (either R10 or R9) being a Hydrogen atom. The invention is particularly applicable in the field of diagnosis.