- Carbohydrate Esters as Inducers for Gene Expression
-
The invention provides novel carbohydrate esters, in particular disaccharide esters, and the methods of their preparation. These compounds find use as microbial media components for the induction of gene expression in microbial fermentation processes.
- -
-
Page/Page column
(2015/06/10)
-
- Purification and characterization of a flavonol 3-O-β heterodisaccharidase from the dried herb of Fagopyrum esculentum Moench
-
A flavonol-3-O-β-heterodisaccharide glycosidase (FHG I) was isolated from dried aerial tissues of Fagopyrum esculentum Moench (Fagopyri herba). It has a specific enzyme activity of ca. 3.5 nkat mg-1 protein in buffered extracts when rutin (quercetin-3-O-rutinoside) was used as substrate and an optimal enzyme activity was seen at around pH 4.8 and 30 °C. FHG I was purified about 156-fold to apparent homogeneity by hydrophobic interaction, anion exchange and size exclusion chromatographic steps. The apparent molecular mass of FHG I was 74.5 ± 2 kDa as determined by SDS-PAGE and it is a monomeric glycoprotein with a carbohydrate content of 23%. The isoelectric point as determined by isoelectric focusing was 5.7 and the energy of activation was 32 kJ mol-1. FHG I exhibits a high substrate specificity, preferring flavonol 3-O-glycosides comprising the disaccharide rutinose. The Km and Vmax values for the natural substrate rutin were calculated to be 0.561 μM and 745 nkat mg -1 protein, respectively. Two oligopeptide fragments obtained after enzymatic digestion of FHG I were sequenced and showed similarities to sequences of β-glucohydrolases from other plant species. Polyclonal antibodies were raised and their specificities determined. Another flavonol 3-O-β -heterodisaccharide glycosidase (FHG II) could also be detected in buckwheat herb, having a molecular mass of 85.3 ± 2 kDa and an isoelectric point between pH 6.0 and 6.5.
- Baumgertel, Andreas,Grimm, Rudi,Eisenbeiss, Wilhelm,Kreis, Wolfgang
-
p. 411 - 418
(2007/10/03)
-
- Composition and method for stimulating pollen germination
-
Composition for application, in particular to leaves, comprising an excipient, the conventional constituents of compositions for application, in particular to leaves, and an active ingredient, characterized by the fact that the active ingredient is constituted by at least one phytosanitary product capable of stimulating the germination of pollen grains, selected from the group comprising: oligosaccharides having a degree of polymerization up to 10 and comprising up to 10, preferably up to 5 and, even more preferably, two glucidic units linked by β1-3, β1-4 et α1-3, particularly those of the group comprising laminaribiose, cellobiose, nigerose, laminaritriose, laminaritetraose and laminaripentaose, derivatives of the above oligosaccharides substituted on the free anomeric carbon atom or on all the carbon atoms having a free hydroxide by a radical selected from the group comprising: C1to C5alkyl radicals, preferably the methyl radical, C1to C5acyl radicals, preferably the acetyl radical, aryl radicals, preferably pyridylamino radicals, cycloalkyl radicals from Cxto Cy, amines, the N-acetyl radical and sulfate and phosphate radicals.
- -
-
-
