Quality Control Studies On Dragon's Blood

Dragon's blood is a deep red resin that has been used for diverse medical purposes for several centuries. Sanguis Draconis, a resin excluded from the fruit of Daemonorops draco. Bl. (family Palm) cultivated in South-East Asian, is the principal source for commercially harvested dragon's blood. In China, Sanguis Draconis is recorded as dragon's blood in the official Chinese pharmacopoeia. However, owing to its rarity, Sanguis Draconis is very expensive in Chinese market, which limits its extensive use in clinical treatments. Following an extensive investigation, Cai and co-workers (1979) have found a dragon's blood substitute, a red resin from the tree-stem of Dracaena cochichinensis (Lour.) S.C.Chen (family Liliacea) and was named Resina Draconis. With pharmacological research improvement, dragon's blood has been extensively exploited for clinical treatment. Correspondingly, more and more fake and defective goods appeared in the market. Although Resina Draconis resembles Sanguis Draconis in many aspects, one major differentiating feature is their financial value. It is therefore necessary to establish an accurate, reliable and convenient method for quality control in order to enable differentiation of both plant products.First, an easy method, based on capillary electrophoresis (CE) with electrochemical detection (ED), for quickly identifying Sanguis Draconis and Resina Draconis and simultaneous determination of loureirin A, loureirin B and dracorhodin in Resina Draconis and Sanguis Draconis. The effects of factors such as the applied potential to the working electrode,concentration of the running buffer, the separation voltage, and the injection time were studied to find the optimum conditions. The optimum CE-ED conditions were as fellows: 0.90 V (vs. SCE) as the applied potential to the working electrode, 20 mmol/L borax (pH 9.24) as the running buffer, the separation voltage at 14 kV and 8s as the injection time. Under the optimum conditions, the analytes were base-line separated within 30 min and excellent linearity was obtained in the concentration range from 5×10-6-1×10-4 g/mL. The analytes in Resina Draconis were also determined with recoveries range from 98.8% to 101.8%, which showed the assay results were satisfactory.Then, a method based on high performance liquid chromatography (HPLC) to establish the fingerprint of Resina Draconis was described. The chromatography was carried out using a Lichrospher C18 (250 mm×4.6 mm i.d., 5μm) column eluted with a linear gradient of acetonitrile (A) and water containing 0.1% phosphoric acid (B), initially at 30:70 (A:B) and changing to 60:40 in 90 min; velocity of flow: 0.6 mL/min; UV detection: 280 nm. Four chromatograms of samples obtained from different pharmaceutical factories showed 20 peaks in common and take the average of them as the fingerprint of standard. Datas of the samples were processed with two kinds of mathematic methods including correlation coefficient and inter-angle-cosine to valuate the similarity. The values were more than 0.91, which showed Resina Draconis samples were consistent. This method was accurate, reliable and could be used to distinguish Sanguis Draconis from Resina Draconis.The last, the method based on Microemulsion electrokinetic chromatography (MEKKC) to establish the fingerprint of Resina Draconis was also described. The microemulsion made up of 3.3% (w/w) sodium lauryl sulfate (SDS),6.6% (v/v) n-butanol, 0.8% (w/w) n-hexane and 10 mmol/L sodium tetraborate buffer (pH 9.2), which was also used as the solvent for ultrasonic extraction. The fingerprint of Resina Draconis comprised 27 common peaks within 100 min. The RSD values of the relative migration time of these common peaks were less than 2.1%, which demonstrated that the method had good stability and reproducibility. Four Electropherograms of samples showed 27 peaks in common and take the average of them as the fingerprint of standard. Datas of the samples were processed with two kinds of mathematic methods including correlation coefficient and inter-angle-cosine to valuate the similarity. The values of similarity degree of all samples were more than 0.90, which showed Resina Draconis samples from different pharmaceutical factories were consistent.