Phenolic Metabolites in the Urine and Plasma of Healthy Men After Acute Intake of Purple Potato Extract Rich in Methoxysubstituted Monoacylated Anthocyanins

Abstract

Scope Structurally stable acylated anthocyanins have potential in various food applications but the effects of acylation and methoxysubstitution on anthocyanin metabolism are poorly understood. This is the first study thoroughly investigating phenolic metabolites, their time‐wise changes, and pharmacokinetics following an acute intake of methoxysubstituted monoacylated anthocyanins. Methods and Results Healthy male volunteers (n = 17) consumed a yellow potato meal with and without purple potato extract rich in acylated anthocyanins (152 mg) and hydroxycinnamic acid conjugates (140 mg). Ultra‐high performance liquid chromatography‐tandem mass spectrometry (UHPLC‐MS/MS) is used for identification and quantification of metabolites from serially collected urine and plasma. While the parent anthocyanins are not detected, 28 phenolic metabolites from urine and 14 from plasma are quantified, including hydroxybenzoic and hydroxycinnamic acids and protocatechuic acid sulfates and glucuronides; three (catechol, gallic acid‐4‐O‐glucuronide, and 2‐methoxybenzoic acid) are detected for the first time after anthocyanin‐rich food. Urinary hippuric acid is the most abundant with an increase of 139 µM mM−1 creatinine after the treatment. A large additional set of tentatively identified phenolic metabolites are detected. Late urinary peak time values suggest colonic degradation. Conclusion Acylated anthocyanins are more bioavailable than earlier reported after extensive degradation in human and/or colonial metabolism to phenolic metabolites, which may be further conjugated and demethylated.

Acylated anthocyanins: A review on their bioavailability and effects on postprandial carbohydrate metabolism and inflammation

“…in vitro incubation of Concord grape juice rich in both nonacylated and acylated anthocyanins (O-acetyl glycosides, O-p-coumaroyl-O-diglucosides, O-p-coumaroylglucosides) in human feces resulted in a variety of phenolic acids, such as phenylacetic acids, phenyllactic acids, and hydrox-ybenzoic acids, and simple phenolic degradants catechol, resorcinol, pyrogallol, and phloroglucinol (Stalmach et al, 2013). In healthy humans, a meal supplemented with a purple potato extract leads to the detection of a variety of phenolic compounds both in urine and plasma (Jokioja et al, 2021).…”

“…In humans, anthocyanins have been found as such and, for example, also as glucuronides of both aglycones and glycosides, sulfated aglycones, and methylated aglycone and glycoside glucuronides (Banaszewski et al, 2013;Czank et al, 2013;Kay et al, 2005;Kuntz et al, 2015;Matsumoto et al, 2001;Mullen et al, 2008;Wiczkowski et al, 2016). Considering acylated anthocyanins, some of purple sweet potatoes (two out of eight) (Harada et al, 2004) and red cabbage (16 out of 18) (Wiczkowski et al, 2016) but none after a meal supplemented with a purple potatoes extract (Jokioja et al, 2021) have been detected in clinical trials. Anthocyanins are further degraded into phenolic metabolites (Section 5.3).…”

“…Clinical trials feeding purple potatoes (Tsang et al, 2015), purple potato extract (Jokioja et al, 2021), and Concord grape juice (38% of acylated anthocyanins) (Stalmach et al, 2011) did not detect acylated anthocyanins in human urine, but other trials detected acylated anthocyanins after the intake of a beverage prepared from a purple sweet potato extract (two out of eight [Harada et al, 2004] and one out of seven [Oki et al, 2006]), steamed and microwaved red cabbage (8 out of 30 [Charron et al, 2007], fresh and fermented red cabbage (16 out of 18 [Wiczkowski et al, 2016]), and raw and microwave-cooked purple carrot (two out of three) (Kurilich et al, 2005), suggesting structure-dependent absorption. In rats, a 3-month feeding with grape anthocyanin-rich extract containing a mix of acylated (22%) and nonacylated anthocyanins leads to the detection of one acylated anthocyanin out of three (petunidin-3-coumaroyl-glucoside) (He et al, 2006).…”

“…In the study of Tsang et al (2015), five healthy volunteers consumed a meal of purple potatoes but only some urinary phenolic metabolites were tentatively identified. Another study showed a vast diversity of phenolic degradants and metabolites after a meal of purple potato extract both in urine and less in plasma (Jokioja et al, 2021). Two studies have investigated the phenolic metabolites after a meal of Concord grape juice containing a mix of nonacylated and acylated anthocyanins (Stalmach et al, 2011(Stalmach et al, , 2013.…”

Metabolomic Characterization of Commercial, Old, and Red-Fleshed Apple Varieties

“…Another important class of polyphenols is that of the anthocyanins. They are hypoglycemic and decrease the risk of type II diabetes [14].…”