Structure and synthesis of phlobatannins related to the (4β,6:4β,8)-bis-fisetinidol-catechin profisetinidin triflavanoid
1996; Elsevier BV; Volume: 43; Issue: 1 Linguagem: Inglês
10.1016/0031-9422(96)00238-5
ISSN1873-3700
AutoresSusan L. Bonnet, Jan P. Steynberg, Barend C. B. Bezuidenhoudt, Catharina M. Saunders, Daneel Ferreira,
Tópico(s)Phytochemicals and Antioxidant Activities
ResumoAdditional members of the class of natural phlobatannins, resulting from stereoselective C-ring isomerization of the 2,3-trans-3,4-cis-flavan-3-ol moieties in the (4β,6:4β,8)-bis-fisetinidol-catechin triflavanoid have been identified from natural sources. These comprise three functionalized hexahydrodipyrano[2,3-f:2′,3′-h]-chromenes and a fisetinidol-(4β,10)-tetrahydropyrano[2,3-f]chromene. The complex structures of these novel natural condensed tannins were confirmed by synthesis via base-catalysed pyran rearrangement of the 4-O(E)-methyl ether of their postulated biogenetic triflavanoid precursor.
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