Determination of Ellagic Acid, Punicalagin, and Castalagin from Terminalia ferdinandiana (Kakadu plum) by a Validated UHPLC-PDA-MS/MS Methodology

Punicalagin, a bioactive ellagitannin predominantly found in Pomegranate, has a wide range of health benefits including potent antioxidant properties. The metabolism of punicalagin in human body produces urolithins and ellagic acid. Ellagic acid is a natural phenolic antioxidant and is also known for its antiproliferative activities. Terminalia ferdinandiana (Kakadu plum) was reported to be a rich source of ellagic acid. In this study, an UHPLC-MS/MS method was developed and validated for accurate determination of ellagic acid levels and bioactive ellagitannins (punicalagin and castalagin). Total ellagic acid content in the fruits and leaves were 2.76 and 9.54 g/100 g DW. Punicalagin contents in the fruits and leaves were 74 and 49 mg/100 g DW, and castalagin contents were 1.1 and 0.8 mg/100 g DW. To the best of our knowledge, this is the first report about punicalagin and castalagin concentrations in Kakadu plum fruits and leaves. The findings are very promising regarding the potential use of Kakadu plum fruit and leaf extracts as natural preservatives in the food industry.