Paulownia tomentosa (Thunb.) Steud. var. tomentosa (Scrophulariaceae) is a well-known medicinal hardwood species native to China and widely distributed in South and East Asian countries [1,2]. Its barks have long been used in folk remedies for the treatment of various diseases and conditions, including gonorrhea, bronchopneumonia, high blood pressure, hemorrhoid, bacteriologic diarrhea, inflammatory bronchitis, erysipelas, carbuncle, upper respiratory tract infection, cough, phlegm, traumatic bleeding, parotitis, asthma, enteritis, tonsillitis, conjunctivitis, and swelling [3,4]. However, the chemical constituents and biological activities of this species have been little reported to date. In this phytochemical study of P. tomentosa var. tomentosa barks, seven secondary metabolites were isolated, and their structures were determined as kaempferol (1) [5], quercetin (2) [6], astragalin (3) [7], hirsutrin (4) [8], astragalin-6cc-gallate (5) [9], hirsutrin-6cc-gallate (6) [10], and cistanoside F (D-and E-forms, 7)[11]. Compounds 1-7 have never been isolated from P. tomentosa var. tomentosa previously. Based on 1D and 2D NMR, MS spectroscopic methods, and other physiochemical techniques, the first unambiguous and complete 1 H and 13 C NMR assignments of compound 7 (D-and E-forms) were achieved in this work. The hydroxyl radical scavenging effects of the isolated metabolites were also evaluated.Plant Material. Barks of P. tomentosa var. tomentosa were collected in Equipment. 1 H and 13 C NMR, DEPT, and correlation NMR spectra including HMQC, HMBC, and TOCOSY were recorded in CD 3 OD or (CD 3 ) 2 CO with TMS as an internal standard with a Bruker Avance DPX 400 spectrometer at the operating frequency of 400 MHz ( 1 H) and 100 MHz ( 13 C). MALDI TOF MS spectroscopy was performed on a Model Voyager-DE STR spectrometer, and positive FAB and EI-MS spectroscopy was measured using a micromass autospec M363 spectrometer. Eluents were collected with a fraction collector (SBS-160). TLC analyses were performed on DC-Plastikfolien Cellulose F (Merck) plates and developed with t-BuOH-AcOH-H 2 O (3:1:1, v/v, solvent A) and AcOH-H 2 O (3:47, v/v, solvent B). Visualization was conducted by UV light (254 and 365 nm) or by spraying with vanillin-AcOH-EtOH (60:0.15:6, w/v/v) or 1% ethanolic FeCl 3 solution followed by heating. Melting points (uncorrected) were determined on an Electrothermal IA 9200 apparatus. Optical rotations were measured on a JASCO DIP 1000 polarimeter in MeOH.