78185-33-8Relevant academic research and scientific papers
Oligomeric flavanoids. Part 26. Structure and synthesis of the first profisetinidins with epifisetinidol constituent units
Steynberg, Petrus J.,Steynberg, Jan P.,Brandt, E. Vincent,Ferreira, Daneel,Hemingway, Richard W.
, p. 1943 - 1950 (2007/10/03)
The natural occurrence of the first oligomeric profisetinidins with (2R,3R)-2,3-cis-epifisetinidol chain extender units is demonstrated in the bark of Pithecellobium dulce (Guamuchil). Semi-synthesis using the appropriate flavan-3-ol and flavan-3,4-diol precursors permits unequivocal structural and stereochemical assignment of the novel dimeric epifisetinidol-(4β,8)-catechin and epicatechins 16 and 18, the trimeric bis-epifisetinidol-(4β,6:4β,8)-catechin and epicatechins 33 and 35, the fisetinidol-(4α,8)-catechin-(6,4β)-epifisetinidol 37 and fisetinidol-(4α,8)-epicatechin-(6,4β)-epifisetinidol 39.
NATURAL (-)-FISETINIDOL-(4,8)-(-)-EPICATECHIN PROFISETINIDINS
Steynberg, Jan P.,Burger, Johann F. W.,Malan, Johannes C. S.,Cronje, Annamarie,Young, Desmond A.,Ferreira, Daneel
, p. 275 - 277 (2007/10/02)
The natural occurrence of the first profisetinidins associated with (-)-epicatechin is demonstrated in the heartwood of three legumes. 1H-NMR spectroscopy at 300 MHz permits assesments of the relative abundance of the predominant rotamers in each of the heptamethyl ether diacetates of the (-)-fisetinidol-(4α,8) and (4β,8)-(-)-epicatechins at ambient temperatures.
Synthesis of Condensed Tannins. Part 11. Intramolecular Enantiomerism of the Constituent Units of Tannins from the Anacardiaceae: Stoicheiometric Control in Direct Synthesis: Derivation of 1H Nuclear Magnetic Resonance Parameters Applicable to
Viviers, Phillip M.,Kolodziej, Herbert,Young, Desmond A.,Ferreira, Daneel,Roux, David G.
, p. 2555 - 2562 (2007/10/02)
Tannins from the heartwoods of Schinopsis spp. (quebracho) and Rhus spp.(karee) represent mutual condensation products of their associated precursors (2S,3R,4S)(-)-leucofisetinidin, (2R,3S)-(+)-catechin and, to a minor extent, (2R,3R)-(-)-epicatechin.The
Synthesis of Condensed Tannins. Part 4. A Direct Biomimetic Approach to - and -Biflavanoids
Botha, Jacobus, J.,Ferreira, Daneel,Roux, David G.
, p. 1235 - 1245 (2007/10/02)
The generation of flavanyl-4-carbo-cations from flavan-3,4-diols and their condensation with nucleophilic flavan-3-ols to form - and -biflavanoids at ambient temperatures and mildly acidic aqueous conditions apparently simulates the initial step in condensed tannin formation in a number of natural sources.The stereospecificity (or stereoselectivity) of the reaction is conditioned mainly by the 2,3-cis or 2,3-trans stereochemistry of the parent flavan-3,4-diol, but also by the nuclephilicity of the flavan-3-ol, and its regiospecific (or regioselective) course by steric factors arising from variation in substitution of the receptive A-ring of the flavan-3-ol.
