ABSTRACT
An interesting article by Quideau (2006), also reported on the Web site of the “Groupe Polyphenols” (https://www.groupepolyphenols.com/), discusses in detail the origin and the present meaning of the term “polyphenols,” at least according to the authors’ opinion. About 50 years ago, this term was normally employed as an equivalent to “vegetable tannins” to indicate those vegetable substances able to convert animal skin into leather (tanning action). Later, Haslam (1998), who examined polyphenols under different points of view, proposed a de˜nition of plant polyphenols, including speci˜c structural characteristics common to all phenolics having a tanning property; however, this de˜nition has subsequently been broadened in the common use to include also low-molecular-weight phenolic molecules, not necessarily water-soluble or exerting a “tanning” action. Consequently, the common feature of polyphenols has been recon˜gured with regard to their biosynthetic origin, thus including phenolic metabolites biosynthetically derived through the shikimate and/or the acetate/malonate pathways. Indeed, metabolic modi˜cation of some shikimate/ acetate intermediates can lead to “polyphenols” paradoxically lacking the phenolic
9.1 Introduction ..................................................................................................299 9.2 Stilbenoids ....................................................................................................302 9.3 Flavonoids .....................................................................................................309
