Jäger Sebastian, Winkler Karin, Pfüller Uwe, Scheffler Armin
Carl Gustav Carus-Institut, Niefern-Oschelbronn, Germany.
Planta Med. 2007 Feb;73(2):157-62. doi: 10.1055/s-2007-967106.
Mistletoe (Viscum album L.) contains the triterpene acids oleanolic acid (OA) and betulinic acid (BA), which were found to have anti-tumour properties. In this study, the solubilities of OA and BA were studied in water (up to 0.02 microg/mL in each case) and in alkaline solutions of 10 mM trisodium phosphate (pH 11.5; OA: 77.2 microg/mL; BA: 40.1 microg/mL). Furthermore, triterpene acids were quantified in aqueous mistletoe extracts (pH 7.3; drug to extract ratio 1:25). OA (1.1 microg/mL) and BA (0.9 microg/mL) were extracted with a yield of less than 5%. Preparing plant extracts with basic pH values resulted in a triterpene acid content of 9.3 microg/mL OA and 5.2 microg/mL BA (pH 12.1), reaching neither the solubility limits nor a complete extraction of the plant material. The triterpene acid content of neutral plant extracts above the solubility limit could be due to interactions with biocolloids. Interaction studies were performed by gel permeation chromatography. Different mechanisms of the dissolution at pH 7.3 and pH 10.2 are discussed.
槲寄生（欧洲槲寄生）含有三萜酸齐墩果酸（OA）和桦木酸（BA），已发现它们具有抗肿瘤特性。在本研究中，研究了OA和BA在水中（每种情况下最高达0.02微克/毫升）以及在10毫摩尔磷酸三钠的碱性溶液（pH 11.5；OA：77.2微克/毫升；BA：40.1微克/毫升）中的溶解度。此外，对槲寄生水提取物（pH 7.3；药物与提取物比例1:25）中的三萜酸进行了定量。OA（1.1微克/毫升）和BA（0.9微克/毫升）的提取率低于5%。制备碱性pH值的植物提取物时，三萜酸含量为9.3微克/毫升OA和5.2微克/毫升BA（pH 12.1），既未达到溶解度极限，也未完全提取植物材料。中性植物提取物中高于溶解度极限的三萜酸含量可能是由于与生物胶体的相互作用。通过凝胶渗透色谱法进行了相互作用研究。讨论了在pH 7.3和pH 10.2时不同的溶解机制。
