¹H NMR and antioxidant profiles of polar and non-polar extracts of persimmon (Diospyros kaki L.) – Metabolomics study based on cultivars and origins

Persimmon (Diospyros kaki L.) is one of the most important fruits that has been consumed for its medicinal properties due to the presence of some active metabolites, particularly polyphenols and carotenoids. Previously described methods, including HPLC, were limited in the determination of metabolites in different persimmon varieties. The present study shows the evaluation and the differences among persimmon polar and non-polar extracts by ¹H NMR-based metabolomics approach. The hierarchical clustering analysis (HCA) based on score values of principal component analysis (PCA) model was used to analyze the important compounds in investigated fruits. The ¹H NMR spectrum of persimmon chloroform (CDCl₃) extracts showed different types of compounds as compared to polar methanol-water (CD₃OD-D₂O) ones. Persimmons growing in Israel were clustered different from those growing in Korea with the abundance of phenolic compounds (gallic, caffeic and protocathecuic acids), carotenoids (β-cryptoxanthin, lutein, and zeaxanthin), amino acids (alanine), maltose, uridine, and fatty acids (myristic and palmitoleic acids). Glucose, choline and formic acid were more prominent in persimmon growing in Korea. In CD₃OD-D₂O and CDCl₃ persimmon extracts, 43 metabolites were identified. The metabolic differences were shown as well on the results of bioactivities and antioxidant capacities determined by ABTS, FRAP, CUPRAC and DPPH assays. The presented methods can be widely used for quantitation of multiple compounds in many plant and biological samples especially in vegetables and fruits.