cyanidin-3-o-beta-d-glucopyranoside and malvidin-3-glucoside

To asses the hypothesis that anthocyanins are rapidly taken up from the blood into tissues, where they accumulate up to their bioactivity threshold, an intravenous dose of cyanidin 3-glucoside (1) was administered to anaesthetized rats. Cyanidin 3-glucoside (1) and its metabolites were analyzed in the plasma, kidneys, liver, urine, and bile, using last-generation mass spectrometry. Compound 1 was found to rapidly disappear from plasma (t/2=0.36 min). As soon as 15 s after its administration, both 1 and its methylation product, peonidin 3-glucoside (2), were detected in the plasma, kidneys, and liver. At 1 min, both 1 and 2 had almost disappeared from the plasma, but attained their peak concentrations in the kidneys and in the liver. Compound 2 was rapidly excreted both in the bile and in the urine. Three additional methylated metabolites were detected in traces, namely, delphinidin 3-glucoside (3), petunidin 3-glucoside (4), and malvidin 3-glucoside (5). These data contribute to solving the paradox of the high bioactivity of anthocyanins in spite of their apparent low bioavailability.

Topics: Animals; Anthocyanins; Bile; Glucosides; Kidney; Liver; Molecular Structure; Rats