UPLC/ESI-Q-TOF-MS analysis of (poly)phenols, tocols and amino acids in Chaenomeles leaves versus in vitro anti-enzyme activities

The aim of this study was to investigate the content of phenolics, free amino acids, tocopherols, tocotrienols and in vitro biological activities (alpha-amylase, alpha-glucosidase, and pancreatic lipase inhibition activity) of 12 cultivars of Chaenomeles x superba, japonica and speciosa leaves. In the present work 39 phenolic compounds were tentatively identified, including polymeric procyanidins > flavan-3-ols > phenolic acids > flavonols > flavanones > flavones > ellagitannins. Chaenomeles leaves contained on average 16.8 g of phenolics per 100 g dr y weight (dw), with C. x superba & PRIME;Nicoline & PRIME; displaying the highest (27.5 g/100 g dw), and C. x superba & PRIME;Colou r Trail & PRIME; the lowest (7.7 g/ 100 g dw) total phenolic content. Chaenomeles leaves possess a l l eight tocol analogs (fou r tocopherols (TP), and four tocotrienols (TT)), ranked in decreasing content: alpha-TP > beta-TP > gamma-T P > delta-TP > alpha-TT > beta-TT > delta-TT > gamma-TT. The most active form (alpha-tocopherol) was present in amounts from 480.6 to 7201.1 mu g/100 g dw. 23 amino acids were identified, including a l l nine essential amino acids. The highest amount of O-phospho-L-serine was found (average 249.2 mg/100 g dw). Leaves of C. japonica & PRIME;Red Joy & PRIME; displayed the highest total amino acid content (2735.2 mg/100 g dw). Chaenomeles leaves showed alpha-amylase (8.2-24.5 mg/mL), alpha-glucosidase (1.2-6.3 mg/mL), and pancreatic lipase (7.0-10.5 mg/mL) inhibition activity (expressed as ha l f maximal inhibitor y concen-tration, IC50). Chaenomeles leaves can be a good material for obtaining extracts rich in phenolics, vitamin E or amino acids, providing an alternative, natural source of these compounds to help meet the growing demand for nutraceuticals and supplements.

Automated summary

This study investigated the content of various nutrients and biological activities of different cultivars of Chaenomeles leaves. The results showed that Chaenomeles leaves are rich in phenolics, free amino acids, tocopherols, tocotrienols, and possess enzyme inhibition activity. They can be used as a valuable source for extracting these compounds.