- Total synthesis of ellagitannins via sequential site-selective functionalization of unprotected D-glucose
-
A short-step total synthesis of the natural glycosides pterocarinin C and tellimagrandin II (eugeniin) has been performed by sequential and site-selective functionalization of free hydroxy groups of unprotected D-glucose. The key reactions are β-selective glycosidation of a gallic acid derivative using unprotected D-glucose as a glycosyl donor and catalyst-controlled site-selective introduction of a galloyl group into the inherently less reactive hydroxy group of the glucoside.
- Takeuchi, Hironori,Ueda, Yoshihiro,Furuta, Takumi,Kawabata, Takeo
-
-
Read Online
- Ellagitannin biosynthesis: Oxidation of pentagalloylglucose to tellimagrandin II by an enzyme from Tellima grandiflora leaves
-
First evidence of the in vitro oxidation of 1,2,3,4,6-pentagalloylglucose to the ellagitannins, tellimagrandin II and 1,4,6-tri-O-galloyl-2,3-O-hexahydroxydiphenoyl-β-D-glucose, has been obtained with a partially purified enzyme from leaves of Tellima grandiflora (fringe cups, Saxifragaceae).
- Niemetz,Schilling,Gross
-
-
Read Online
- Synthesis of enantiomerically pure unusual ellagitannins 1,4,6-tri-O- galloyl-2,3-(R)-hexahydroxydiphenoyl-β-D-glucopyranoside and 4,6-di-O- galloyl-2,3-(R)-hexahydroxydiphenoyl-D-glucoside. The proposed chemical structures for cercidinin A and B must be revised
-
The total syntheses of the enantiomerically pure unusual ellagitannins 1,4,6-tri-O-galloyl-2,3-(R)hexahydroxydiphenoyl-β-D-glucopyranoside (1) and 4,6-di-O-galloyl-2,3-(R)-hexahydroxydiphenoyl-D-glucoside (2) are reported. The NMR data of the synthetic ellagitannins 1 and 2 are not identical with those reported for cercidinin A and B. Thus, the proposed structures for cercidinin A and B must be revised.
- Khanbabaee, Karamali,Loetzerich, Kerstin
-
p. 8723 - 8728
(2007/10/03)
-