63783-75-5Relevant 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 (1997)
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.
Oligomeric Flavonoids. Part 16. Novel Prorobinetinidins and the First A-Type Proanthocyanidin with a 5-Deoxy A- and 3,4-cis-C-Ring from the Maiden Investigation of Commercial Wattle Bark Extract
Cronje, Annemarie,Steynberg, Jan P.,Brandt, E. Vincent,Young, Desmond A.,Ferreira, Daneel
, p. 2467 - 2478 (2007/10/02)
Structural examination of the phenolic metabolites of commercially used wattle bark extract reveals the presence of a range of novel flavonoids comprising (-)-epirobinetinidol 1, the first C-methyl proanthocyanidin, (-)-fisetinidol-(4α,8)-6-methyl-(+)-catechin 3, the first prorobinetinidins with 3,4-cis-C-ring configurations 7 and 9, and the unique A-type prorobinetinidin 11 representing the first entry amongst this class of oligoflavonoids exhibiting a 5-deoxy A- and a 3,4-cis-C-ring.They are accompanied by a range of functionalized prorobinetinidin-type tetrahydropyranochromenes 20, 23, 25 and 28 and the trimeric 'isomerization-intermediate' 32, all exhibiting the characteristic structural features that are essential for the use of 'Mimosa' exctract in cold-setting adhesives and leather-tanning applications.In addition, evidence demonstrating that the dynamic A-E conformational equilibrium of flavan-3-ol moieties in condenced tannins may be influenced by external factors is presented.
