Smejkal Karel, Holubova Pavla, Zima Ales, Muselik Jan, Dvorska Margita
Natural Drugs Department, Faculty of Pharmacy, University of Veterinary and Pharmaceutical Sciences Brno, Palackého 1-3, CZ-612 42 Brno, Czech Republic.
Molecules. 2007 Jun 27;12(6):1210-9. doi: 10.3390/12061210.
Paulownia tomentosa is a large indecidous tree planted mostly for its fast growing wood and decorative purposes. The tree is also used in traditional Chinese medicine. As a part of our study of natural polyphenols, the fruits of Paulownia tomentosa were extracted by EtOH and than subjected to liquid/liquid extraction. Fractions were analysed by TLC and HPLC to determine presence of phenolic substances. We identified and quantified acteoside (1) and isoacteoside (2) in the EtOAc and n-BuOH extracts; mimulone (3) and diplacone (4) in the MeOH extract. To determine the antiradical activity of extracts we used the anti DPPH and peroxynitrite assays. The activity was expressed as Trolox C equivalents, IC50 for DPPH scavenging and a time dependency course was established. The polyphenols content was determined; results were expressed as gallic acid equivalents. Using these methods we found the fractions of the n-BuOH, EtOAc and MeOH extracts that display antiradical activity, which could be exploited as potential pharmaceuticals.
毛泡桐是一种大型落叶乔木，主要因其速生木材和装饰用途而种植。这种树也用于传统中药。作为我们对天然多酚研究的一部分，毛泡桐果实用乙醇提取，然后进行液-液萃取。通过薄层色谱法（TLC）和高效液相色谱法（HPLC）分析各馏分，以确定酚类物质的存在。我们在乙酸乙酯和正丁醇提取物中鉴定并定量了毛蕊花糖苷（1）和异毛蕊花糖苷（2）；在甲醇提取物中鉴定并定量了刺槐苷（3）和二氢异黄酮（4）。为了测定提取物的抗自由基活性，我们采用了抗二苯基苦味酰基自由基（DPPH）和过氧亚硝酸盐测定法。活性以Trolox C当量表示，确定了DPPH清除的半数抑制浓度（IC50）并建立了时间依赖性过程。测定了多酚含量；结果以没食子酸当量表示。使用这些方法，我们发现了正丁醇、乙酸乙酯和甲醇提取物中具有抗自由基活性的馏分，这些馏分可作为潜在药物加以利用。
