Colophospermum mopane

Fig. 2.3 Flavonoid diversity in the heartwood constituents of Colophospermum mopane (Leguminosae subfamily Caesalpinioideae). Stmctural types present with illustrative example(s) flavonol fisetin (11) dihydroflavonol (+)-taxifolin (12) flavan-3-ols (+)-catechin (13) and (-)-fisetinidol (14) flavan-3,4-diol (+ )-gleditsin (15) peltogynoid epimopanol (16) profisetinidin fisetinidol-(4a 8)-catechin (17) proguibourtinidin guibourtinidol-(4a— 8)-catechin (18) propeltogynidin (-)-epipeltogynane-(4a 6)-(-)-fisetinidol (19) trimeric profisetinidin fiseti-nidol.(4a— 6)-catechin-(8— 4a)-fisetinidol (20) tetrahydropyranochromene 21 and hexahydropyranochiomene 22.

Although a number of flavan-3-ols of the IS configuration are known, their distribution is quite restricted in comparison with the above compounds. Both eAZ/-epiafzelechin and eA epicatechin are found in several species of the Palmae (73). Afzelia xylocarpa and Colophospermum mopane contain eA2/-fisetinidol, and e epifisetinidol is also present in the latter species (66, 82, 323). The flavan-3-ols readily undergo epimerization through inversion of configuration at C-2, making precautions necessary in their isolation. The above compounds clearly are not artifacts, however. 

The profisetinidins have been studied intensively by Roux s school at The University of the Orange Free State, Bloemfontein, South Africa. The heartwoods of Acacia mearnsii and Colophospermum mopane contain a series of 2R isomers and these compounds have all been synthesized (Tables 7.6.9 and 7.6.10). The commercially important quebracho tannins from Schinopsis and Rhus contain a series of 2S isomers and these compounds have also been synthesized recently. Fifteen dimers, nine trimers, and nine tetramers have now been thoroughly de-... 

Drewes S E, Roux D G 1965 Absolute configuration of mopanol, a new leucoanthocyanidin from Colophospermum mopane. J Chem Soc Chem Commun 500-501... 

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