Quercetin glucosides structures

Figure 8.4 The structures of the four major quercetin conjugates present in plasma following ingestion of a quercetin glucoside-rich meal.

The flavonoids, luteolin, luteolin 7-0-/3-d-xyloside and cynaroside, were isolated by El-Moghazi et al. (1979) and orientin and vitexin by Akunzemann and Herrmann (1977). Quercetin-3-glucuronide, rutin, isoorientin, isovitexin and apigenin-7-glucoside have been reported from aniseed (Ozguven, 2000). Figure 18.2 depicts the structure of flavonoids in aniseed. 

Fig. 13 Structures of quercetin-3-O-rhamnoside (59), cyanidin-3-O-glucoside (60) and catechin-3-O-glucoside (anthocyanin) (61)...

Fig. 4 Structures of phytochemical components in dietary supplements undergoing evaluation of benefits in chronic diseases (+)-catechin (a flavanol), quercetin (a flavonol), resveratrol (a stilbenoid), lycopene (a carotenoid), genistein (an isoflavone) and puerarin and daidzin (8-C- and 7-O-glucosides of the isoflavone daidzein). They are each drawn so that the A ring is in the same orientation...

P-D-glucopyranoside, two flavonol glycosides, quercetin-3-0-P-D-glucoside and quercetin-7-a-L-rhamnoside and four triterpenes, 2a,3a,19a-trihydroxy-12-oleanen-28-oic acid, euscaphic acid, 2a-hydroxyoleanolic acid and oleanolic acid. Their structures were elucidated on the basis of spectral and chemical evidences. 

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