Efficient total synthesis of the natural products , and the unnatural

Conformation of the tridimensional structure of 1,2,3,4,6‐pentagalloyl‐β‐D‐glucopyranose (PGG) by 1H NMR, NOESY and theoretical study and membrane interaction in a simulated phospholipid bilayer: a first insight

“…The 1 H NMR data and the assignments of PGG protons in different deuterated solvents have already been reported: DMSO‐ d 6 ,20 acetone‐ d 6 ,21–23 deuterated water/acetone‐ d 6 24 and methanol‐ d 4 ,2 and comparisons of chemical shifts and multiplicities reported by different authors are shown in Table 1. The PGG proton resonances obtained by Ren et al 21 working with PGG in DMSO‐ d 6 were reported without assignments; hence, in the present study they were attributed by comparison with the assignments reported by us and by the other authors.…”

Pseudotannins self-assembled into antioxidant complexes

“…The phenolic residues were chosen because of their presence on naturally occurring tannins. The conjugation of each to the dextran was based on the esterification reaction described previously 21 with modifications 25 . Figure 2 illustrates the reaction scheme for the esterification and deprotection steps using polygallol as an example.…”

“…A method for the synthetic production of PGG was described by Khanbabaee and Lotzerich. 21 This method was adapted by replacing the central glucose core with a polysaccharide of controlled size (Figure 1). In this way, we were able to create pseudotannins across a range of sizes.…”

Preparation of 1,2,3,4,6‐penta‐O‐galloyl‐[U‐14C]‐D‐glucopyranose

“…8 This modification reduced the reaction time from 36 to 6 h. Centrifugal thinlayer chromatography (TLC), using a Chromatotron, was an improvement over column chromatography for the purification. Clean separation of the impurities from the products was easily achieved, and less ½ 14 C-contaminated solvent waste was produced.…”

“…7 We now report adaptation of a previously reported chemical synthesis of PGG to access PGG uniformly ½ 14 Clabeled at the hexose. 8 Using chemical synthesis, a higher specific activity radiolabeled product could be obtained versus biochemical methods. Furthermore, modification of our procedure will allow synthesis of structural variants of PGG that are not biosynthetically accessible.…”