Identification of Anthocyanins in Red Grape, Plum and Capulin by MALDI-ToF MS

A simple and fast method was developed to identify anthocyanins in red grapes, plums and capulins by MALDI-ToF MS. Three different matrices were used: alpha-CHCA (alpha-cyano-4-hydroxycinnamic acid), THA (2',4',6'-trihydroxyacetophenone) and DHBA (2,5-dihydroxybenzoic acid). Post-Source Decay (PSD) fragment detection allowed studying the structure of compounds detected. Deprotonated anthocyanin species were assigned in capulin ([Cyanidin-3-glucoside-deprotonated] K+ and [Cyanidin-3-rutinoside-deprotonated]K+), due to these compounds also can be ionized in form of potassium adducts combined with a deprotonation.