LAUSR

Chemical composition of the extract from the Pinus roxburghii Sarg. knotwood was studied for the first time. The extracts were obtained by ultrasound assisted sequential extraction of knotwood with hexane, acetone—water (95 : 5, v/v), and water. According to GC-MS analysis, hexane extract was dominated by monoterpenoids amounting to 53.57% and sesquiterpenoids (41.05%). Components of the acetone—water (95 : 5, v/v) extract were isolated, purified by HPLC, and identified by NMR spectroscopy and mass spectrometry as 2,3-bis(4-hydroxy-3-methoxybenzyl)butan-1,4-diol, 3-hydroxy-3,4-bis(4-hydroxy-3-methoxybenzyl)dihydrofuran-2(3H)-one and 3,4-bis(4-hydroxy-3-methoxybenzyl)dihydrofuran-2(3H)-one. These compounds demonstrated notable antioxidant capacity determined using the amperometric method.