Selective and Sensitive LC-MS Determination of Avenanthramides in Oats

Phenolic amides (avenanthramides) in oats - a review

“…AVAs are important phenolic compounds found in oats. They are constitutively expressed in the kernels, appearing in almost all milling fractions, but occur in the highest concentration in the bran and outer layers of the kernel (Peterson et al 2002;Jastrebova et al 2006;Meydani 2009). Their concentrations are affected by the genotype and growing environment, in one location the combined concentration of A, B and C having exceeded 300 mg/kg (Emmons & Peterson 2001;Peterson et al 2002).…”

“…AVAs are generally determined by various chromatographic methods. For the determination of the AVAs amounts, highperformance liquid chromatography (HPLC) (Bryngelsson et al 2002;Peterson et al 2002;Chen et al 2004;Mattila et al 2005;Jastrebova et al 2006;Skoglund et al 2008;Wise et al 2011;Ortiz-Robledo et al 2013;Ishihara et al 2014;Koening et al 2014), liquid chromatography-mass spectrometry (LC-MS) (Okazaki et al 2004), liquid chromatography-mass/ mass spectrometry (LC-MS/MS) (Ishihara et al 2014), and ion-exchange chromatography (Collins 1989) have been used. HPLC currently represents the most popular technique for the analysis of AVAs.…”

Bioactivity of oats as it relates to cardiovascular disease

“…Chemically, avenanthramides are amides of different cinammic acids with different anthranilic acids 128 . They are distinguished based on their particular anthranilic acid component which may include anthranilic, 5-hydroxy-anthranilic, 5-hydroxy-4-methoxy-anthranilic or 4-hydroxy-anthranilic acids 129 . Avenathramides composed of anthranilic acid and 5-hydroxy-anthranilic acids are referred to as group 1 and 2, respectively.…”

“…2) are the most commonly investigated since they consistently appear in higher concentrations in oat extracts 129,130 . In fact, avenanthramide-2c constitutes about one-third of the total avenanthramide content in oat grain 132 .…”

“…Oat phenols increased the lag time to LDL oxidation in a dose-dependent manner, and lag times were increased synergistically by combining oat phenols with vitamin C. There is a general consensus that further research is needed to elucidate the mechanisms that underpin avenathramide bioactivity including anti-inflammatory and antioxidant activities, particularly in vivo 15,137 . The need for more sensitive and selective methods for determining avenanthramides is apparent, as is the need to isolate and identify unknown avenanthramides occurring in trace quantities in oats 129 . For example, sinapic acid is also found in oats, yet it is not known whether avenanthramides derived from this cinnamic acid exist 135 .…”