ABSTRACT
This review will focus on the bioavailability and pharmacokinetics (PK) of two classes of dietary compounds, namely, isothiocyanates (ITCs) and avonoids. Isothiocyanates form a class of dietary compounds that are present in Brassica and other vegetables of the family Cruciferae (e.g., broccoli, brussels sprouts, cauliower, kale, watercress) and the genus Raphanus (radishes and daikons). Organic isothiocyanates (R-N = C = S) (Figure 8.1) occur in plants as thioglycoside conjugates known as glucosinolates. Flavonoids comprise the most common type of plant polyphenols and provide much of the avor and color to fruits and vegetables (Ross and Kasum 2002). Some major subclasses of avonoids include the avanones (e.g., hesperetin, naringenin); avonols (e.g., quercetin, myricetin); avan-3-ols (e.g., catechins); isoavones (e.g., genistein, biochanin A, daidzein); and avones (e.g., apigenin, chrysin, luteolin) (Figure 8.2). Flavonoids are present in fruits, vegetables, and plant-derived beverages, as well as in a multitude of dietary supplements, either as a single avonoid or as simple or complex mixtures.
