Flavonoids, chemistry flavanones

Grayer RJ and Veitch NC. Flavanones and dihydroflavonols. In Anderson OM, Markham KR. editors. Flavonoids Chemistry, Biochemistry and Applications. Boca Raton, FL CRC Press/Taylor Francis Group, pp. 918—1002. 

From a chemosystematic point of view, it is interesting to note that prenylated flavonoids such as microfolione (56) have been found in a species of the family Ptaeroxylaceae, because the relationships of this family with other families were disputed in the past. Most taxonomists considered the Ptaeroxylaceae closely related to families in the order Rutales to which the Rutaceae and Meliaceae belong, whereas others considered it related to the Sapindaceae. Flavonoid chemistry supports a close relationship to the Rutaceae and Meliaceae, as iso-prenylated flavanones also occur in these families, e.g., 58 and 98 in Boronia coerulescens ssp. spinescens, the farnesyl-bearing 121 (Figure 15.3) in B. ramosa (Rutaceae)," and flowerine (59) and flowerone (60) in Azadirachta indica (Meliaceae). Microfolione is one of the few new flavanones for which the (2i )-configuration has been determined. 

Jannie P. J. Marais studied at the University of the Free State, Bloemfontein, South Africa where he obtained his Ph.D. in organic chemistry in 2002. His research focused on characterization of the free phenolic profile of South African red wine, and the stereoselective synthesis of flavonoids, for example, flavan-3,4-diols and flavanones. He joined the National Center for Natural Products Research at the University of Mississippi as a postdoctoral associate in July of 2002, where he worked with Dr. Ferreira on the stereoselective synthesis of flavonoid precursors, the semi-synthesis of proanthocyanidin oligomers, characterization of proanthocyanidin profiles of selected transgenic plants, and the synthesis of radioactive antimalarial 8-aminoquinolines. He was promoted to associate research scientist in 2005, where his main area of research still remains the synthesis of A- and B-type proanthocyanidins, starting at the monomeric level and continuing through the tri- and tetra-meric, to the deca-mer level. 

They are also interesting compounds because they are the obligate intermediates in flavonoid biosynthesis. Although flavanones are minor chemical constituents of plants, they have attracted a lot of attention in chemistry and biological sciences. 

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