13080-40-5

Upstream product

• 133-89-1 UDP-glucose 
• 331-39-5 caffeic acid 
• 331-39-5 caffeic acid 
• 2492-87-7 4-nitrophenyl-β-D-glucoside 

Downstream Products

• 20905-74-2 3,5-di-O-β-D-glucopyranoside of cyanidin 

Relevant academic research and scientific papers

Engineering faster transglycosidases and their acceptor specificity

Transglycosidases are enzymes that have the potential to catalyze the synthesis of a wide range of high-value compounds starting from biomass-derived feedstocks. Improving their activity and broadening the substrate range are important goals to enable the widespread application of this family of biocatalysts. In this work, we engineered 20 mutants of the rice transglycosidase Os9BGlu31 and evaluated their catalysis in 462 reactions over 18 different substrates. This allowed us to identify mutants that expanded their substrate range and showed high activity, including W243L and W243N. We also developed double mutants that show very high activity on certain substrates and exceptional specificity towards hydrolysis, such as L241D/W243N. In order to guide a more general use of Os9BGlu31 variants as transglycosylation catalysts, we built cheminformatics models based on topological descriptors of the substrates. These models showed useful predictive potential on the external validation set and are allowing the identification of efficient catalytic routes to novel phytohormone and antibiotic glucoconjugates of interest.

Identification of UGT84A13 as a candidate enzyme for the first committed step of gallotannin biosynthesis in pedunculate oak (Quercus robur)

A cDNA encoding the ester-forming hydroxybenzoic acid glucosyltransferase UGT84A13 was isolated from a cDNA library of Quercus robur swelling buds and young leaves. The enzyme displayed high sequence identity to resveratrol/hydroxycinnamate and hydroxybenzoate/hydroxycinnamate glucosyltransferases from Vitis species and clustered to the phylogenetic group L of plant glucosyltransferases, mainly involved in the formation of 1-O-β-d-glucose esters. In silico transcriptome analysis confirmed expression of UGT84A13 in Quercus tissues which were previously shown to exhibit UDP-glucose:gallic acid glucosyltransferase activity. UGT84A13 was functionally expressed in Escherichia coli as N-terminal His-tagged protein. In vitro kinetic measurements with the purified recombinant enzyme revealed a clear preference for hydroxybenzoic acids as glucosyl acceptor in comparison to hydroxycinnamic acids. Of the preferred in vitro substrates, protocatechuic, vanillic and gallic acid, only the latter and its corresponding 1-O-?-D-glucose ester were found to be accumulated in young oak leaves. This indicates that in planta UGT84A13 catalyzes the formation of, 1-O-galloyl-?-D-glucose, the first committed step of gallotannin biosynthesis.

Chemical synthesis of hydroxycinnamic acid glucosides and evaluation of their ability to stabilize natural colors via anthocyanin copigmentation

This work describes the chemical synthesis of O-aryl-β-D-glucosides and 1-O-β-D-glucosyl esters of hydroxycinnamic acids. In particular, O-aryl-β-D-glucosides were efficiently prepared via a simple diastereoselective glycosylation procedure using phase transfer conditions. Despite the lability of its ester linkage, 1-O-β-D-caffeoylglucose could also be obtained using a Lewis acid catalyzed glycosylation step and a set of protective groups that can be removed under neutral conditions. Hydroxycinnamic acid O-aryl-β-D-glucosides were then quantitatively investigated for their affinity for the naturally occurring anthocyanin malvin (pigment). Formation of the π-stacking molecular complexes (copigmentation) was characterized in terms of binding constants and enthalpy and entropy changes. The glucosyl moiety did not significantly alter these thermodynamic parameters, in line with a binding process solely involving the polyphenolic nuclei.

Antiviral composition derived from allium CEPA and therapeutic use thereof

Novel medicinal extracts derived from Allium species, preferablyAllium cepaare provided. These extracts have broad medicinal properties, especially for treatment of AIDS and other viral infections.