Activity-Guided Screening of the Antioxidants from Paulownia tomentosa var. tomentosa Bark

Chuan-Ling Si, Shi-Chao Liu, Hai-Yan Hu, Ju-Zheng Jiang, Guo-Jing Yu, Xiao-Dan Ren, Guang-Hui Xu

Abstract


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.

Keywords


Isolation and purification; Structure elucidation; Total phenolic contents; Paulownia tomentosa var. tomentosa; Antioxidative activity; Activity-guided screening

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Welcome to BioResources! This online, peer-reviewed journal is devoted to the science and engineering of biomaterials and chemicals from lignocellulosic sources for new end uses and new capabilities. The editors of BioResources would be very happy to assist you during the process of submitting or reviewing articles. Please note that logging in is required in order to submit or review articles. Martin A. Hubbe, (919) 513-3022, hubbe@ncsu.edu; Lucian A. Lucia, (919) 515-7707, lucian.lucia@gmail.com URLs: bioresourcesjournal.com; http://ncsu.edu/bioresources ISSN: 1930-2126