Composition and Content of Hydrolysable Tannins in Feijoa Leaves, <i>Acca sellowiana</i>

Abstract

Introduction. Acca sellowiana, or feijoa belongs to the Myrtaceae family and it is an evergreen shrub or small tree 4–6 meters high. The phytochemical composition has been most thoroughly studied in the fruits of A. sellowiana. It has been shown that feijoa is rich in phenolic acids, hydrolysable and condensed tannins, steroidal saponins, and flavonoids. Hydrolysable tannins are known to have high biological activity.Aim. To study the composition and content of hydrolysable tannins in the leaves of A. sellowiana.Materials and methods. Ultra-high performance liquid chromatography coupled with diode array detection and mass spectrometry.Results and discussion. The results obtained showed the presence of 22 phenolic compounds in the extract of the A. sellowiana leaves. They have been classified as flavan-3-ols, flavonoids and hydrolysable tannins. Two compounds could not be identified. The total content of hydrolysable tannins was 44,28 mg/g (90 % of the total phenolic content). At the same time, ellagitannins were the main phenolic compounds of the extract (40,47 mg/g), while the amount of galloyl-glucose was only 3,81 mg/g.Conclusions. Composition and content of hydrolysable tannins in the leaves of A. sellowiana introduced in the greenhouse of VILAR have been studied. The leaves accumulate mainly monomeric ellagitannins represented 92 % of the total content of hydrolysable tannins. The data obtained indicate that the leaves of A. sellowiana can be used as a raw material for obtaining extracts with a high content of ellagitannins and developing drugs based on them.