Plitzko Inken, Mohn Tobias, Sedlacek Natalie, Hamburger Matthias
Institute of Pharmaceutical Biology, University of Basel, Basel, Switzerland.
Planta Med. 2009 Jun;75(8):860-3. doi: 10.1055/s-0029-1185447. Epub 2009 Mar 18.
A proposal for a European Pharmacopoeia monograph concerning Indigo naturalis has recently been published, whereby the indigo (1) and indirubin (2) content should be determined by HPLC-UV. This method was tested, but problems were seen with the dosage of indigo due to poor solubility. A quantitative assay for indigo based on (1)H-NMR was developed as an alternative. The HPLC and qNMR assays were compared with eight Indigo naturalis samples. The HPLC assay consistently gave much lower indigo concentrations because solubility was the limiting factor in sample preparation. In one sample, sucrose was identified by (1)H-NMR as an organic additive. Simple wet chemistry assays for undeclared additives such as sugars and starch were tested with artificially spiked Indigo naturalis samples to establish their limits of detection, and sulfate ash determinations were carried out in view of a better assessment of Indigo naturalis in a future European monograph.
最近发布了一项关于欧洲药典中天然靛蓝专论的提案，其中靛蓝（1）和靛玉红（2）的含量应由高效液相色谱 - 紫外法测定。对该方法进行了测试，但由于溶解度差，在靛蓝的定量方面出现了问题。开发了一种基于氢核磁共振（¹H-NMR）的靛蓝定量测定方法作为替代方法。将高效液相色谱法和定量核磁共振法与八个天然靛蓝样品进行了比较。高效液相色谱法测定的靛蓝浓度始终低得多，因为溶解度是样品制备中的限制因素。在一个样品中，通过氢核磁共振（¹H-NMR）鉴定出蔗糖为有机添加剂。用人工加标的天然靛蓝样品测试了针对未申报添加剂（如糖和淀粉）的简单湿化学分析方法，以确定其检测限，并进行了硫酸盐灰分测定，以便在未来的欧洲专论中更好地评估天然靛蓝。
