Qualitative profiling and relative quantitative analysis of compounds in light-harvested and shading-treated sumac (Toxicodendron vernicifluum) leaves and their antibacterial activity

Abstract

Sumac ( Toxicodendron vernicifluum ) is a highly valuable industrial tree species. The leaves are rich in secondary metabolites such as urushiol and flavonoids , which have a wide range of industrial uses. In this study, HPLC-QTOF-MS/MS was used to analyze the compounds in the ethyl acetate extracts of light-harvested and shading-treated sumac leaves. A total of 110 compounds were identified, including 10 urushiol compounds, 57 flavonoids and 43 other compounds. Most of the compounds were not reported in sumac to date. Light was an important environmental factor correlated with the presence of different compound categories and their relative content. The content of all the urushiol compounds in shading-treated leaves decreased compared with the light-harvested leaves, while the content of 33 flavonoids and the total flavonoid content in shading-treated leaves increased. The content of most alkaloids and terpenoids in shading-treated leaves was lower than the light-harvested leaves. The minimum inhibitory concentrations (MIC) and minimum bactericidal concentrations (MBC) assays showed that extracts from sumac leaves had obviously antibacterial activity, although the antibacterial activity of the shading-treated leaves was decreased. This study offers a new perspective for regulating the synthesis of substances through light management to enable the full utilization of sumac leaf resources. • Urushiol(triene) was the most abundant compound in Toxicodendron vernicifluum leaves. • 110 compounds were identified in sumac leaves and most were first reported in sumac. • Shading treatment decreased the urushiol content and increased flavonoids content. • The extracts from Toxicodendron vernicifluum leaves had strong antibacterial activity.