1268481-34-0

Upstream product

• 14937-32-7 tannic acid 

Downstream Products

• 73493-42-2 β-1,2,3-tri-O-galloyl-4,6-(S)-hexahydroxydiphenoyl-D-glucose pentadecamethyl ether 
• 23094-68-0 (11aR,14R,15R,15aS)-2,3,4,5,6,7,13,14,15-nonahydroxy-11,11a,13,14,15,15a-hexahydrodibenzo[g,i]pyrano[3,2-b][1,5]dioxacycloundecine-9,17-dione 
• 1707-75-1 2,2-diphenyl-1-picrylhydrazine 

Relevant academic research and scientific papers

Non-Enzymatic Oxidation of a Pentagalloylglucose Analogue into Members of the Ellagitannin Family

The occurrence of more than 1000 structurally diverse ellagitannins has been hypothesized to begin with the oxidation of penta-O-galloyl-β-d-glucose (β-PGG) for the coupling of the galloyl groups. However, the non-enzymatic behavior of β-PGG in the oxidation is unknown. Disclosed herein is which galloyl groups tended to couple and which axial chirality was predominant in the derived hexahydroxydiphenoyl groups when an analogue of β-PGG was subjected to oxidation. The galloyl groups coupled in the following order: at the 4,6-, 1,6-, 1,2-, 2,3-, and 3,6-positions with respective S-, S-, R-, S-, and R-axial chirality. Among them, the most preferred 4,6-coupling reflected the what was observed for natural ellagitannins. A new finding was that the second best coupling occured at the 1,6-positions. With the detection of a 3,6-coupled product, this work demonstrated that even ellagitannin skeletons with an axial-rich glucose core may be generated non-enzymatically.

Total synthesis of ellagitannins through regioselective sequential functionalization of unprotected glucose

Short total syntheses of natural glycosides (ellagitannins) were performed through sequential and regioselective functionalization of the hydroxy groups of unprotected glucose. The key reactions are β-selective glycosidation of a gallic acid derivative by using unprotected glucose as a glycosyl donor and catalyst-controlled regioselective introduction of a galloyl group into the inherently less reactive hydroxy group of the glucoside.

Gallotannins and ellagitannins as regulators of cytokine release

A means and method for increasing or inhibiting the secretion of cytokines using gallotannins and ellagitannins is described. The preferred cytokine release inhibiting compounds are dimeric gallotannins having a linker molecule that misaligns the carbohydrate cores of the compounds. The preferred cytokine release promoting gallotannins and ellagitannins include a diaryl ether linker unit. In comparison to the more structurally complex ellagitannins, the compounds of this invention are structurally simpler, easier to synthesize, and more potent.

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).

Ellagitannin chemistry. Syntheses of tellimagrandin II and a dehydrodigalloyl ether-containing dimeric gallotannin analogue of coriariin A

The first chemical synthesis of the naturally occurring ellagitannin tellimagrandin II is reported. Key steps of the synthesis include the atropselective oxidative coupling of suitably protected galloyl rings at the O(4) and O(6) positions of a glucopyranose core, and the stereoselective acylation of the derived anomeric alcohol with a galloyl chloride. In addition, the synthesis of a novel gallotannin-ellagitannin hybrid is described. This dimeric construct relied on a hetero-Diels-Alder cycloaddition/reductive rearrangement sequence to deliver the intact skeleton from a monomeric pentagalloylglucose-based orthoquinone.