Maturity stage-specific metabolite profiling of Cudrania tricuspidata and its correlation with antioxidant activity

•Metabolite profiling of Cudrania tricuspidata was conducted at different maturity stages.•Metabolite changes of C. tricuspidata were presented by maturity stages.•Flavonoid, TPC, and TFC were positively correlated with antioxidant activity.•High levels of prenylflavonoids affected the antioxidant activity.

Metabolite profiles of four different maturity stages (immature, pre-mature, fully-mature, and over-mature) of Cudrania tricuspidata fruit (Moraceae) were analyzed by gas chromatography–time-of-flight-mass spectrometry and ultra-performance liquid chromatography–quadrupole/time-of-flight-mass spectrometry combined with multivariate analysis. Principal component analysis and partial least squares discriminant analysis showed distinct patterns based on the maturity stages. Primary metabolites such as amino acids, organic acids, sugars, and sugar alcohols were identified as discriminant metabolites that are dependent on four different maturity stages. Secondary metabolites such as flavonoids, lysophosphatidylcholines, and anthocyanins were major metabolites separated according to the different maturity stages. The highest antioxidant activity and relatively high levels of total phenolic contents (TPC) and total flavonoid contents (TFC) were shown at the fully mature stage. In particular, relatively high contents of prenylflavonoids such as artocarpesin (1), 6-isopentenylgenistein (2), alpinumisoflavone (3), 6,8-diprenylgenistein (4), and 4′-O-methylalpinumisoflavone (5), which were reported as antioxidants, were observed and shown to be positively correlated with antioxidant activities, and TPC and TFC. These results suggest that prenylflavonoid, TPC, and TFC were associated with antioxidant activity of the fully mature stage of C. tricuspidata fruit.