INVESTIGADORES
VOJNOV Adrian Alberto
artículos
Título:
Study of bioactive compounds from plants rosmarinus officinalis L. with antioxidant activity
Autor/es:
CATALINA S. ROMANO; KARINA ABADI; MARIA V. REPETTO; GABRIEL VICHERA; ADRIÁN A. VOJNOV; SILVIA MORENO
Revista:
Molecular Medicinal Chemistry
Editorial:
INSTITUTO DE INVESTIGACIÓN DE LAS CIENCIAS EXACTAS FÝSICAS Y NATURALES
Referencias:
Año: 2006 p. 43 - 46
ISSN:
1666-888X
Resumen:
In Xanthomonas campestris the genes involved in polysaccharide (xanthan) biosynthesis are located in a gene cluster (gum) of 16 kb. A Tn5 insertion mutant with a reduced slimy phenotype has been characterized. This mutant failed to produce the pentasaccharide repeating-unit of xanthan. Only three sugars were transferred to the prenyl phosphate intermediate. Several lines of evidence suggested that the lipid-associated saccharide was the trisaccharide reducing end of the pentasaccharide from the wild-type strain. This trisaccharide was built up from UDP-Glc and GDP-Man, and a glucose residue was at the reducing end, linked to an allylic prenol through a diphosphate bridge. Results from one- or two-stage reactions showed that the trisaccharide- P–P-polyprenol was the precursor of the polymer. This new polymer, a polytrisaccharide, was detected also in vivo. The transposon responsible for the mutation was located within gumK gene. Therefore, this gene encodes for the glycosyltransferase IV, which catalyses the transfer of glucuronic acid to the lipid-linked -D-Manp-(13)--D-Glcp-(14)--D-Glcp trisaccharide. A recombinant plasmid with the whole gum cluster restored the wild type phenotype. © 2002 Elsevier Science Ltd. All rights reserved.