103883-03-0Relevant articles and documents
Syntheses of doubly linked proanthocyanidins using free flavan units as nucleophiles: Insight into the origin of the high regioselectivity of annulation
Betkekar, Vipul V.,Harachi, Mio,Suzuki, Keisuke,Ohmori, Ken
, p. 9129 - 9134 (2019)
A synthesis method of doubly linked flavan dimers is reported via the acid-promoted annulation reaction using nascent catechins, (+)-catechin or (-)-epicatechin, as a dianionic partner and an ethylenedioxy-bridged flavan as a dicationic partner. Procyanidins A1 and A2 were synthesized. On the high regioselectivity of the annulation reactions, model experiments and computational studies were carried out.
Conversion of procyanidin B-type (catechin dimer) to A-type: Evidence for abstraction of C-2 hydrogen in catechin during radical oxidation
Kondo, Kazunari,Kurihara, Masaaki,Fukuhara, Kiyoshi,Tanaka, Takashi,Suzuki, Takashi,Miyata, Naoki,Toyoda, Masatake
, p. 485 - 488 (2000)
Procyanidin B-1 and B-2 were converted into A-1 and A-2 by radical oxidation using 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals under neutral conditions, respectively. Transformation of procyanidin B-type into A-type certainly shows abstraction of the hy
Structures and antioxidant and intestinal disaccharidase inhibitory activities of A-type proanthocyanidins from peanut skin
Zhang, Huiwen,Yerigui,Yang, Yumei,Ma, Chaomei
, p. 8814 - 8820 (2013)
Nine compounds including a new A-type proanthocyanidin trimer, epicatechin-(2β→O→7,4β→8)-[catechin-(6→4β)] -epicatechin (8), and a known trimer, epicatechin-(4β→8)-epicatechin- (2β→O→7,4β→8)-catechin (9), being reported for peanut skin for the first time, were isolated and purified. Their structures were determined by spectroscopic methods and by degradation reactions with l-cysteine in acidic conditions. The DPPH radical scavenging activity and the inhibitory activity on maltase and sucrase of the isolated compounds were investigated. All compounds showed strong DPPH scavenging activities (EC50 50 value of 0.088 mg/mL, while compound 9 exhibited the strongest inhibition on sucrase with an IC50 value of 0.091 mg/mL.
Total Synthesis of Proanthocyanidin A1, A2, and Their Stereoisomers
Sharma, Pradeep K.,Romanczyk, Leo J.,Kondaveti, Leelakrishna,Reddy, Bollu,Arumugasamy, Jeeva,Lombardy, Richard,Gou, Yanni,Schroeter, Hagen
supporting information, p. 2306 - 2309 (2015/05/27)
The first novel stereoselective synthesis of naturally occurring A1 (1) and A2 proanthocyanidins (2) has been achieved. The key synthetic steps involved (a) the formation of a coupled product (13 or 14) between an open chain C-ring C-4 hydroxyethoxy analo
Tannins and Related Compounds. LX. Isolation and Characterization of Proanthocyanidins with a Doubly-Linked Unit from Vaccinium vitis-idaea L.
Morimoto, Satoshi,Nonaka, Gen-Ichiro,Nishioka, Itsuo
, p. 33 - 38 (2007/10/02)
New proanthocyanidin trimers (14 and 15) and tetramers (16 and 17) have been isolated from the whole body of Vaccinium vitis-idaea L. (Ericaceae).The structures of these proanthocyanidins were established by thiolytic degradation and by analyses of the proton and carbon-13 nuclear magnetic resonance spectra.In addition, the presence of (-)-epicatechin (1), (+)-catechin (2), (-)-epigallocatechin (3), (+)-gallocatechin (4), procyanidins B-1 (5), B-3 (6), A-1 (8) and A-2 (9), and cinnamtannins B1 (10), D1 (11), B2 (12) and D2 (13) in this plant was demonstrared.Keywords - Vaccinium vitis-idaea; Ericaceae; doubly-bonded proanthocyanidin; procyanidin; condensed tannin; flavan-3-ol; thiolytic degradation
Tannins and Related Compounds. L. Structures of Proanthocyanidin A-1 and Related Compounds
Nonaka, Gen-Ichiro,Morimoto, Satoshi,Kinjo, Jun-Ei,Nohara, Toshihiro,Nishioka, Itsuo
, p. 149 - 155 (2007/10/02)
The structures of proanthocyanidin A-1 (2) and two related proanthocyanidins, tentatively named A-4 (3) and A-5' (4), have been established unambiguously on the basis of spectroscopic evidence and chemical correlations with the structurally known proantho
