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Tree barks, as a type of forestry residues, are a rich and renewable bioresource that can produce high value-added products. Paulownia tomentosa var. tomentosa (PTT) has been extensively used in traditional Chinese medicine to cure various diseases. However, the antioxidative activity of the chemical constituents of the tree has not yet been investigated. In this study, the bark of PTT were extracted and fractioned. Then the resulting ethyl acetate (EtOAc) soluble fraction, which exhibited the strongest antioxidative effect, was subjected to repeated open column chromatography for purification. The screening process was carried out under the guidance antioxidative activity via diphenylpicrylhydrazyl (DPPH) radical scavenging assay. Eight phenolic compounds, glucodistylin (I), luteolin (II), ellagic acid (III), cistanoside F (IV), campneoside II (V), isocampneoside II (VI), verbascoside (VII), and isoverbascoside (VIII), were isolated and their structures were elucidated by various spectroscopic analyses. Among the phenolics, II~VIII showed significant antioxidative activity.

Phytochemical investigation of branch wood of Pinus banksiana Lambert resulted in the isolation of a new lignan glycoside, which was named phillyrin-6 ″ -α -rhamnoside. The structure of the new compound was mainly elucidated by chemical and spectral evidence including 2D nuclear magnetic resonance studies. In addition, four known phenolics, including a phenylpropanoid glucoside (trans-isoconiferin), a phenolic acid (caffeic acid), a neolignan (cedrusin), and a lignan glucoside (phillyrin), were reported for the first time to be present in P. banksiana.

Eucommia ulmoides Oliv. ("Du Zhong" in Chinese and "Tu Chung" in Korean), the sole species in the genus Eucommia and family Eucommiaceae, is a deciduous tree indigenous in China and widely cultured in eastern Asian countries [1]. The species is highly valued and commonly used in traditional medicines to treat various diseases, especially to relieve hypertension, protect the nervous system, treat diabetics, cure lower back pain, and prevent miscarriage [2,3]. Previous phytochemical investigations of E. ulmoides were mainly focused on its stem barks and leaves. However, the chemical constituents of E. ulmoides root have not been reported to date. As one chain of our systematic study of this valuable medicinal species, 13 secondary metabolites, including one triterpene [ursolic acid (1)], four phenylpropanoids [chlorogenic acid (2), caffeic acid (3), ferulic acid (4), and p-coumaric acid (5)], and eight flavonoids [luteolin (6), kaempferol (7), quercetin (8), astragalin (9), hirsutin (10), avicularin (11), quercitrin (12), and rutin (13)], were isolated from the root barks of E. ulmoides Equipment. 1 H, 13 C, and correlation NMR spectra were recorded in (CD 3 ) 2 CO or CD 3 OD (Sigma) with TMS (Sigma) as an internal standard on a Bruker Avance DPX 400 spectrometer at the operating frequency of 400 MHz ( 1 H) and 100 MHz ( 13 C). EI and positive FAB-MS spectra were measured with a micromass autospec M363 spectrometer. Eluents were collected using an SBS-160 fraction collector. Thin-layer chromatography were carried out 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 by UV light (254 and 365 nm) and by spraying with vanillin-AcOH-EtOH (60:0.15:6, w/v/v) or 1% ethanolic FeCl 3 solution followed by heating. 1)

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