Comprehensive phenolic profiling of Australian-grown Progrades™ Desmanthus through LC-ESI-QTOF-MS2 and determination of their antioxidant potential

Desmanthus is a Mimosaceae legume genus that is native to the Americas. Decades ago, the introduction of Desmanthus with impressive survival ability in semi-clay soil filled the gap of no sown pasture legume adaptive to the northern Australian environment. In this study, the comprehensive phenolic profile of Progrades™ Desmanthus collected across northwestern Queensland was characterised by LC-ESI-QTOF-MS2. Their antioxidant potential was evaluated by the in vitro antioxidant assays and correlatively analysed with the phenolic contents. As discovered, the phenolic contents varied significantly among geographical locations. Desmanthus collected from Armreynold showed the highest phenolic content mainly consisting of condensed tannins, whereas the Madison region sample displayed the highest flavonoid content. The mass spectrometry results identified 68 phenolic compounds, highlighting 21 phenolic acids and 36 flavonoids. This study provides academic evidence for the utilisation of Desmanthus in food and husbandry industries as an antioxidant ingredient or a potential source of phenolic compounds.