1237502-34-9Relevant academic research and scientific papers
C-glycosidic ellagitannin metabolites in the heartwood of Japanese chestnut tree (Castanea crenata SIEB. et ZUCC.)
Tanaka, Takashi,Ueda, Nobuko,Shinohara, Hideo,Nonaka, Gen-Ichiro,Fujioka, Toshihiro,Mihashi, Kunihide,Kouno, Isao
, p. 2236 - 2242 (1996)
HPLC comparison of tannins in the bark, sapwood and heartwood of Castanea crenata showed striking differences of composition. The major tannin of the bark is hamamelitannin, whereas vescalagin and castalagin are dominant in the wood. Inner heartwood contained three new C-glycosidic ellagitannin metabolites, castacrenins A, B and C. Outer heartwood contained dimeric, trimeric (castaneanin A), tetrameric (castaneanins B and C) and pentameric (castaneanin D) C-glycosidic ellagitannins composed of vescalagin and castalagin units. Castacrenins and castaneanins are derived from vescalagin and castalagin by intramolecular and intermolecular dehydration, respectively.
Tannins and related compounds. CXVII. Isolation and characterization of three new ellagitannins, lagerstannins A, B and C, having a gluconic acid core, from Lagerstroemia speciosa (L.) Pers
Tanaka,Tong,Xu,Ishimaru,Nonaka,Nishioka
, p. 2975 - 2980 (2007/10/02)
Lagerstannins A (6), B (11) and C (8), ellagitannins having a gluconic acid core, have been isolated from the fruits and leaves of Lagerstroemia speciosa (L.) Pers. (= L. flos-reginae Retz.) (Lythraceae). On the basis of chemical and spectroscopic evidence, their structures were established as 2,3;4,6-bis-O-(S)-hexahydroxydiphenoyl-D-gluconic acid (6), 2,3,5-O-(S,R)-flavogallonyl-4,6-O-(S)-hexahydroxydiphenoyl-D-gluconic acid (11), and 5-O-galloyl-4,6-O-(S)-hexahydroxydiphenoyl-D-gluconic acid (8), respectively. Furthermore, the structure of an ellagitannin, punigluconin, previously isolated from the bark of Punica granatum L., was revised as 2,5-di-O-galloyl-4,6-O-(S)-hexahydroxydiphenoyl-D-gluconic acid (10), based on spectral re-examination.
Tannins and Related Compounds. XLII. Isolation and Characterization of Four New Hydrolyzable Tannins, Terflavins A and B, Tergallagin and Tercatain from the Leaves of Terminalia catappa L.
Tanaka, Takashi,Nonaka, Gen-Ichiro,Nishioka, Itsuo
, p. 1039 - 1049 (2007/10/02)
A chemical examination of the leaves of Terminalia catappa L. (Combretaceae) has led to the isolation and characterization of four new hydrolyzable tannins named terflavins A (1) and B (2), tergallagin (3) and tercatain (4), together with eight known tannins: punicalin (5), punicalagin (6), chebulagic acid (7), geraniin (8), granatin B (9), l-desgalloyleugeniin (10), corilagin (11) and 2,3--D-glucose (12).Terflavins A (1) and B (2) posses novel structures in which a flavogallonyl (triphenyl) ester group is single bonded to the glucopyranose ring, and are presumed to be biosynthetic precursors of punicalagin (6) and punicalin (5), respectively, while tergallagin (3), which contains a gallagyl (tetraphenyl) group and a unique tergalloyl ester group attached to the glucose moiety, seems to be formed biosynthetically from punicalagin (6).Keyword - Terminalia Cattapa; Combretaceae; terflavin A; terflavin B; tercatain; hydrolyzable tannin; tergallic acid; flavogallonic acid; biosynthesis
