Study of Chemical Components and Bioactive Properties of Knot wood Extractives from Four Endemic Species of Hyrcanian Forests

Persian wingnut, Persian honeylocust, Persian ironwood and Persian alder are of four endemic and important species of Hyrcanian forests that initial data about the presence of bioactive components in them are available, however no comprehensive study has been done about their chemical components yet. Furthermore, bioactive phenolics are more in knot wood extractives than other parts of a tree, in this study, the amounts of extractives, carbohydrates, lignin, as well as antioxidant properties of acetonic extractives were calculated and the extractives components were identified via Gas Chromatography-Mass Spectrometry. The results demonstrated that the knot wood of Persian wingnut contains the most amount of extractives, carbohydrates and phenolics and showed the most ability against Diphenylpicrylhydrazyl radicals, while the knot wood of Persian honeylocust contains the most amount of lignin and capability against chelating of iron ion. All of these four species presented superior scavenging capability against radicals compared to synthetic antioxidant, Butylated hydroxytoluene. Besides, phenolics and non-phenolics with different and interesting antioxidant properties were identified.