The above [sup.1]H-NMR pattern suggests that the compound has flavan
skeleton with two aromatic protons (H-6 and 8) on ring A and three aromatic protons (H-2', 5', and 6') on ring B and devoid of the carbonyl group at C-4 of ring C.
The basic flavonoid structure is the flavan
nucleus consisting of a 15-carbon skeleton arranged in two phenyl rings bound by a three-carbon bridge commonly encircled by oxygen, then forming three rings (Figure 1) .
(136) Rutgers proclaims, "Scientists have developed a proprietary method of extracting and purifying a novel type of piperidine flavan
alkaloids from the leaves of Combretum micranthum (kinkeliba) and a procedure for the preparation of total piperidine flavan
alkaloids (TPFA) that possess anti-diabetic properties." (137) Paralleling that of the previous two case studies, it does not appear that a specific traditional community, organization, or government within West Africa claimed the use of combretum micranthum as their intellectual property or specifically accused Rutgers of misappropriation.
Costa (2005).' Luteoforol, a flavan
4-ol, is induced in pome fruits by prohexadione-Ca and shows phytoalexin-like properties against Erwiniaamylovora and other plant pathogens'.
oxyacantha contains heptahydroxy flavan
They are present in the grape seed extracts and are composed of flavan
units linked by [C.sub.4]-[C.sub.6] or [C.sub.4]-[C.sub.8] bonds forming dimmers, trimers, tetramers, and polymers up to 15 to 16 units (Prieur et al., 1994) with small amounts of catechin and epicatechin (Ricardo da Silva et al., 1990).
Northern Ireland's most in-demand shoe designer Anita Flavan
came to the rescue at the Fate Awards last weekend - with a pair of killer heels for my missus.
In the 60th minute Graham Stuart put Saunders away for the striker to draw Flavan
before chipping over his head only to see Russ Perrett hook the ball off the line.
(+)-Catechin was identified as the major active flavan
in the A.
The basic structural feature of flavonoids is the 2-phenylbenzopyrane or flavan
nucleus, which consists of two benzene rings linked through a heterocyclic pyran ring (Brown 1980).