3,4,6-Tri-O-galloyl-D-glucose

Metabolite profiling of polyphenols in a Terminalia chebula Retzius ayurvedic decoction and evaluation of its chemopreventive activity.[Pubmed:23506992]

J Ethnopharmacol. 2013 May 20;147(2):277-85.

ETHNOPHARMACOLOGICAL RELEVANCE: The decoction of Terminalia chebula fruit is an ayurvedic remedy whose prolonged oral administration is prized as a generic intestinal and hepatic detoxifying agent. Its administration is suggested also under the perspective of a reduced risk of cancer, metabolic and cardiovascular diseases. AIM OF THE STUDY: To evaluate the phytochemical profile and the chemopreventive potential of Terminalia chebula fruit decoction prepared according to the ayurvedic decoction recipe. MATERIALS AND METHODS: The quali- and quantitative metabolite profiling of polyphenols was obtained using HPLC-UV/DAD and HPLC-ESI-MS. The crude decoction and purified compounds were tested for their capability to interact with the EphA2-ephrin-A1 system and for their antimutagenic properties against dietary and environmental mutagens (AA, 2-NF, NaN3, and heterocyclic amines IQ, MeIQ, MeIQx, Glu-P1, Glu-P2,) in the Ames-Salmonella/microsome assay, with and without enzymatic induction. RESULTS: The decoction was found to contain 3,4,6-Tri-O-galloyl-D-glucose (55.87 mg/g), chebulic acid (54.03 mg/g), beta-punicalagin (41.25mg/g), corilagin (40.31 mg/g), alpha-punicalagin (35.55 mg/g), chebulagic acid (29.09 mg/g), gallic acid (27.96 mg/g) 1,3,4,6-tri-O-galloyl-beta-d-glucose (24.25mg/g) chebulinic acid (20.23 mg/g), 1,2,3,4,6-penta-O-galloyl-d-glucose (13.53 mg/g), ellagic acid (8.00 mg/g), 1,6-di-O-galloyl-d-glucose (4.16 mg/g). An inhibitory effect was recorded in both Salmonella typhimurium TA98 and TA100 strains against the mutagenic activity of heterocyclic amines (22-61%), promutagen AA (91-97%) and directly acting mutagen 2-NF (52%) with but not against NaN3 (7%). Galloyl derivatives allowed an inhibition of mutagenicity induced by MeIQ above 80% at 0.01 mol/plate. Both decoction and purified compounds were able to modulate the EphA2-ephrinA1 system, suggesting a potential multiple chemopreventive mechanism. CONCLUSIONS: The traditional ayurvedic decoction of Terminalia chebula may harbour a potential as a safe and low-cost chemopreventive agent at the intestinal level, if administered according to the ayurvedic specifications. Moreover, its recourse may enhance the presence of some polyphenolic constituents.

Characterisation of galloylated cyanogenic glucosides and hydrolysable tannins from leaves of Phyllagathis rotundifolia by LC-ESI-MS/MS.[Pubmed:21495106]

Phytochem Anal. 2011 Nov-Dec;22(6):516-25.

INTRODUCTION: Phyllagathis rotundifolia (Jack) Bl. (Melastomataceae) is a creeping herb found in Peninsular Malaysia and Sumatra. Traditionally, a decoction of the leaves is used in the treatment of malaria, fever and stomach ache. OBJECTIVE: To provide ESI-MS(n) data which are applicable for chemical fingerprinting of P. rotundifolia to obviate laborious isolation and purification steps. METHODOLOGY: The mass spectral data for the compounds isolated from the leaves of P. rotundifolia were obtained by liquid chromatography-electrospray ionisation tandem mass spectrometry. RESULTS: The MS fragmentation patterns were obtained for galloylated cyanogenic glucosides based on prunasin (prunasin 6'-O-gallate 1, prunasin 2',6'-di-O-gallate 2, prunasin 3',6'-di-O-gallate 3, prunasin 4',6'-di-O-gallate 4, prunasin 2',3',6'-tri-Ogallate 5, prunasin 3',4',6'-tri-O-gallate 6 and prunasin 2',3',4',6'-tetra-O-gallate 7), gallotannins (6-O-galloyl-D-glucose 8, 3,6-di-O-galloyl-D-glucose 9, 1,2,3-tri-O-galloyl-beta-D-glucose 10, 1,4,6-tri-O-galloyl-beta-D-glucose 11, 3,4,6-Tri-O-galloyl-D-glucose 12, 1,2,3,6-tetra-O-galloyl-beta-D-glucose 13 and 1,2,3,4,6-penta-O-galloyl-beta-D-glucose 14), ellagitannins [6-O-galloyl-2,3-O-(S)-hexahydroxy-diphenoyl-D-glucose 15, praecoxin B 16 and pterocarinin C 17], ellagic acid derivatives (3'-O-methyl-3,4-methylenedioxyellagic acid 4'-O-beta-D-glucopyranoside 18 and 3,3',4-tri-O-methylellagic acid 4'-O-beta-D-glucopyranoside 19) and gallic acid 20 that were isolated from the leaves of P. rotundifolia. CONCLUSION: The ESI-MS(n) technique facilitates identification of galloylated cyanogenic glucosides, hydrolysable tannins and ellagic acid derivatives that were isolated from the leaves of P. rotundifolia. It yields MS(n) spectra that are useful for identification of these compounds in complex samples and permit more complete fingerprinting of plant materials.

Determination of hydrolyzable tannins in the fruit of Terminalia chebula Retz. by high-performance liquid chromatography and capillary electrophoresis.[Pubmed:15387468]

J Sep Sci. 2004 Jun;27(9):718-24.

A RP-HPLC method for determining fourteen components (gallic acid, chebulic acid, 1,6-di-O-galloyl-D-glucose, punicalagin, 3,4,6-Tri-O-galloyl-D-glucose, casuarinin, chebulanin, corilagin, neochebulinic acid, terchebulin, ellagic acid, chebulagic acid, chebulinic acid, and 1,2,3,4,6-penta-O-galloyl-D-glucose) in the fruit of Terminalia chebula Retz. is described. The separation was achieved within 80 min using a binary gradient with mobile phases consisting of a pH 2.7 phosphoric acid solution and an 80% CH3CN solution. Capillary electrophoretic analyses were also attempted, and it was found that CZE (25 mM Na2B4O7, 5 mM NaH2PO4, pH 7.0) was an efficient method for the separation of gallotannins, while an MEKC method (25 mM Na2B4O7, 5 mM NaH2PO4, 20 mM SDS, pH 7.0, and 10% acetonitrile) provided a better separation for most of the tannins examined. The HPLC and CE methods developed were both successfully applied to the assay of tannins in commercial samples of Chebulae Fructus.

Synthesis of gallotannins.[Pubmed:11595218]

Carbohydr Res. 2001 Oct 15;335(4):245-50.

As a contribution to the synthesis of gallotannins, four O-galloyl-D-glucoses (3-O-, 6-O-, 3,6-di-O-, 3,4,6-Tri-O-galloyl-D-glucose) have been prepared by the reaction of tri-O-benzylgalloyl chloride and partially protected glucose derivatives (1,2-O-, and 1,2:5,6-di-O-isopropylidene-alpha-D-glucofuranose), followed successively by catalytic debenzylation (Pd-C) and controlled acid hydrolysis. Their structures were established from their behavior on TLC and from their 1H and 13C NMR spectra.