Metabolite profiling of Ipomoea aquatica at different growth stages in correlation to the antioxidant and α-glucosidase inhibitory activities elucidated by 1H NMR-based metabolomics

• 1HNMR fingerprint and MVA was applied to discriminate Ipomoea aquatica.
• PCA demonstrated clear separation between the growth stages.
• Major metabolites contributed to discrimination of samples were identified.
• Correlation between biological activity and metabolite variation are discussed.

Ipomoea aquatica Forsk is a green leafy vegetable that is a rich source of secondary metabolites, vitamins and amino acids with many health benefits. Proton Nuclear Magnetic Resonance (1H NMR) spectroscopy was combined with multivariate data analyses to distinguish Ipomoea aquatica samples at different developmental stages. A principal component analysis (PCA) of Ipomoea leaves provides clusters based on the different developmental stages by combining principal components PC1 and PC2 with a total variance of 65.1%. A loading plot analysis revealed that the initial stages (weeks 3 and 4) showed comparatively low contents of phenolic and organic acids, such as citric and maleic acid; the latter stages (weeks 5 and 6) exhibited higher glucose and phenolic compound contents. The sugar, phenolic compound and organic acid contents increased based on the developmental stage of the Ipomoea aquatica. The latent structures were projected using a partial least squares (PLS) model to predict the biological activity of the Ipomoea extracts based on their 1H NMR spectra. The results of this study indicate that 1H NMR-based metabolomics data could be used to discriminate the different developmental stages and to predict the biological activities of Ipomoea leaves. The present study may be applied when monitoring the quality of fruits and vegetables.