13405-60-2Relevant articles and documents
Two UGT84 family glycosyltransferases catalyze a critical reaction of hydrolyzable tannin biosynthesis in pomegranate (Punica granatum)
Ono, Nadia N.,Qin, Xiaoqiong,Wilson, Alexander E.,Li, Gang,Tian, Li
, (2016)
Hydrolyzable tannins (HTs) play important roles in plant herbivore deterrence and promotion of human health. A critical step in HT production is the formation of 1-O-galloyl-β-D-glucopyranoside (β-glucogallin, ester-linked gallic acid and glucose) by a UDP-glucosyltransferase (UGT) activity. We cloned and biochemically characterized four candidate UGTs from pomegranate (Punica granatum), of which only UGT84A23 and UGT84A24 exhibited β-glucogallin forming activities in enzyme assays. Although overexpression and single RNAi knockdown pomegranate hairy root lines of UGT84A23 or UGT84A24 did not lead to obvious alterations in punicalagin (the prevalent HT in pomegranate) accumulation, double knockdown lines of the two UGTs resulted in largely reduced levels of punicalagins and bis-hexahydroxydiphenyl glucose isomers. An unexpected accumulation of galloyl glucosides (ether-linked gallic acid and glucose) was also detected in the double knockdown lines, suggesting that gallic acid was utilized by an unidentified UGT activity for glucoside formation. Transient expression in Nicotiana benthamiana leaves and immunogold labeling in roots of pomegranate seedlings collectively indicated cytosolic localization of UGT84A23 and UGT84A24. Overall, functional characterization and localization of UGT84A23 and UGT84A24 open up opportunities for further understanding the regulatory control of HT metabolism in plants and its coordination with other biochemical pathways in the metabolic network.
Gallotannins and Tannic Acid: First Chemical Syntheses and in Vitro Inhibitory Activity on Alzheimer's Amyloid β-Peptide Aggregation
Sylla, Tahiri,Pouységu, Laurent,Dacosta, Grégory,Deffieux, Denis,Monti, Jean-Pierre,Quideau, Stéphane
, p. 8217 - 8221 (2015/07/07)
The screening of natural products in the search for new lead compounds against Alzheimer's disease has unveiled several plant polyphenols that are capable of inhibiting the formation of toxic β-amyloid fibrils. Gallic acid based gallotannins are among these polyphenols, but their antifibrillogenic activity has thus far been examined using "tannic acid", a commercial mixture of gallotannins and other galloylated glucopyranoses. The first total syntheses of two true gallotannins, a hexagalloylglucopyranose and a decagalloylated compound whose structure is commonly used to depict "tannic acid", are now described. These depsidic gallotannins and simpler galloylated glucose derivatives all inhibit amyloid β-peptide (Aβ) aggregation invitro, and monogalloylated α-glucogallin and a natural β-hexagalloylglucose are shown to be the strongest inhibitors.
COMPOUNDS REDUCING THE PRODUCTION OF SORBITOL IN THE EYE AND METHODS OF USING THE SAME
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, (2014/02/16)
Methods of inhibiting the progression of or treating secondary complications of diabetes, especially a diabetic eye disease, in a mammal by inhibiting the production of sorbitol in the mammal. Small molecule inhibitors of sorbitol production in the eye useful in the methods of the invention and pharmaceutical compositions containing the compounds, and methods of using the same.