Flavonol glucoside

Chemical investigation of the leaves of Ehretia dentata Couch. growing in Hoa Binh, Vietnam led to the isolation and structural elucidation of a nitril glucoside, ehretioside A1, the flavonol glucoside astragalin, as well as rosmarinic acid and methyl rosmarinat. These structures were determined on the basis of MS and NMR spectroscopic data.

5p uocvong04 24-09-2015 53 3   Download

Flavonol 3-O-glucosides esterified with ferulic or p-coumaric acid at posi-tions 3¢¢ and 6¢¢ are the major UV-B screening pigments of the epidermal layer of Scots pine (Pinus sylvestris) needles. The last steps in the biosyn-thesis of these compounds are catalyzed by enzymes that transfer the acyl part of hydroxycinnamic acid CoA esters to flavonol 3-O-glucosides. A newly developed enzyme assay revealed three flavonol 3-O-glucoside hydroxycinnamoyltransferases (HCTs) in Scots pine needles with specifici-ties for positions 3¢¢,4¢¢ or 6¢¢. ...

0p awards 06-04-2013 36 3   Download