Plant polyphenol flavanones

Flavonoids are a diverse family of plant polyphenols and of special interest due to their potential in the treatment of various human diseases. The first attempts to produce flavonoid precursors were accomplished by cloning of the flavanone pathway consisting of cinnamate-4-hydroxylase (CYP73A5) from A. thalima together with 4-coumaroyl CoA ligase (4CL), chalcone synthase (CHS), and chalcone isomerase (CHI) in S. cerevisiae [410], The generated strain was able to convert cinnamic acid to 200 pg naringenin... 

Bio active polyphenols are present in a variety of plants and are used as important components of human and animal diets [27]. Flavonoids are a broad class of low-molecular-weight secondary plant polyphenolics, which are benzo-y-pyrone derivatives consisting of phenolic and pyrane rings. Flavonoids are usually subdivided according to their substituents into fla-vanols, flavones, flavanones, chalcones, and anthocyanidines. 

In addition to the bitter acids and essential oils, the flowers of hops offer a rich array of polyphenolic compounds, primarily chalcones and their accompanying flavanones, many of which are prenylated derivatives (Stevens et al., 1997,1999a, b). The most prominent flavonoid in all plants studied was xanthohumol [342] (3 -prenyl-6 -0-methylchalconaringenin chalconaringenin is 2, 4, 6, 4-tetrahydroxychalcone) (see Fig. 4.11 for structures 342-346). Several additional chalcones—variously adorned with 0-methyl and/or C-prenyl functions—were also encountered, along with their respective flavanones. Three new compounds were described in the Stevens et al. 

Plant-derived products Polyphenols (derivatives of hydroxycinnamic acid, hydroxybenzoic acid, flavonols,3 flavones,3 anthocyanidins,3 flavanols,3 isoflavones,3 flavanones,3 stilbenes, lignans), glucosynolates, carotenoids (am /3-, y-, 8-carotene, lycopene, luthein, xeaxantin, canthaxantin), phytic acid, allicin... 

Flavonoids are a group of polyphenolic compounds present ubiquitously in plants. Flavanones are a class of flavonoids, present abundantly in Citrus species. 

The polyphenols are a series of phytochemicals synthesized by plants. They include the bioflavonoids anthocyanins, coumestanes, flavonoids, isoflavonoids, and stil-benes (Figure 4.1). Each bioflavanoid class is subdivided into other groups, e.g., flavones, flavans, flavanols, flavonols, and flavanones (Figure 4.2). Another class of polyphenol is the oligomeric polyphenols, such as the proanthocyanidins, found in the grape and various berries (black currant, blueberry, etc.). 

Flavonoids are a class of plant secondary metabohtes that are abundant components of fruit and vegetables. They are divided into five major subclasses flavonols, flavan-3-ols (monomers and proanthocyanidins), flavones, flavanones and anthocyanins (Manach etal. 2004). Isoflavones are a class of dietary polyphenols present in soya-based foods. The structiues of representative compounds from each of these polyphenol subclasses are shown in Figure 8.2 (also see Chapter 1). Flavonoids and isoflavones have received attention due to their potent antioxidant activity and possible role in the prevention of cancer, cardiovascular, neurodegenerative and infectious diseases as well as osteoporosis. 

---