Chemical composition and antibacterial properties of stem and leaf extracts from Ginja cherry plant

In this work the first systematic study on the composition and the antibacterial properties of the extracts from the stems and the leaves of Ginja cherry are reported. This native Portuguese cherry (Prunus cerasus, L. Rosaceae) is used to make a liquor (Ginjinha); both stems and leaves are a by-product of this process.The extracts from stems and leaves were prepared using different solvents (ethyl acetate, ethanol, acetone and water); their analysis was performed with GC-MS. Thirty-six volatile compounds were identified; terpenes - both hydrocarbons and oxygenated - were the main class of compounds.The extracts made from the stems with ethyl acetate were particularly rich in these species; compounds such as linalool, α-pinene, 4-terpineol and cedrene were present in concentration more than 10 times higher than in the other extracts.The antibacterial properties of all the extracts were tested against eight bacterial strains; the values of the minimum inhibitory concentration and minimum bactericidal concentration were determined. The stem extracts in ethyl acetate were the most active, showing bacteriostatic and bactericidal activity towards Gram-positive and Gram-negative microorganisms.This study showed that these by-products can be successfully valorized with solvent extraction of valuable compounds. The antibacterial properties of these extracts, combined with their antioxidant activity, make them suitable to be employed in areas like cosmetics and food packaging.