拳参中没食子酸和总鞣质的含量测定

Determination of gallic acid and total tannins in Polygonum bistorta

关键词:  拳参, 没食子酸, 鞣质, 高效液相色谱

Key words:  Polygonum bistorta, gallic acid, tannin, HPLC

摘要:

该研究采用高效液相色谱法和紫外分光光度法分别对拳参中的主要成份——没食子酸以及总鞣质进行含量测定。其中,用高效液相色谱法测定没食子酸的含量,HPLC条件为Hypersil GOLD Phenyl 柱(250 mm × 4.6 mm, 5 μm),甲醇-0.1%磷酸梯度洗脱,流速为1.0 mL·min^-1,检测波长为276 nm。用紫外分光光度法测定总鞣质的含量,采用2010版《中国药典》一部附录XB中鞣质含量测定方法,用干酪素沉淀鞣质,通过干酪素沉淀前后鞣质的变化来确定样品中总鞣质的含量。结果表明:没食子酸在0.051～1.02 μg范围内呈现良好的线性关系,平均加样回收率分别为99.1%、100.3%、101.9%,RSD分别为2.1%、0.8%、2.0%; 总鞣质在2.09～10.48 μg范围内呈现良好线性关系,平均加样回收率分别为102.2%、100.2%、102.1%,RSD分别为1.3%、1.4%、1.0%。利用上述方法,还测定了贵州贵阳和四川成都各3批样品中没食子酸和总鞣质的含量差异,发现成都样品中的没食子酸与总鞣质均大于贵阳拳参中的含量,初步分析导致这一结果的原因可能与拳参的生长海拔有关,而成都的海拔范围更适合拳参的生长。上述两种方法快速、简单、重现性好,可以作为拳参中没食子酸和总鞣质的含量测定方法,而该方法也是首次被用来同时测定拳参中没食子酸和总鞣质的含量,为今后的地方药典标准甚至《中国药典》标准的补充和完善提供了重要依据。

Abstract:

To further complement and perfect about content of Chinese Pharmacopoeia, the major component-gallic acid and total tannins in Polygonum bistorta were determined by high performance liquid chromatography(HPLC)and ultraviolet(UV)spectrophotometric methods for the essay, respectively. The HPLC condition for determination of gallic acid with Hypersil GOLD phenyl column(250 mm × 4.6 mm, 5 μm)and a mobile phase consisted of methanol and 0.1% phosphoric acid by gradient elution at a flow rate of 1.0 mL·min^-1. The detection wavelength was 276 nm by wavelength scanning from 190-400 nm. On the other side, the total tannins were determined by Casein Method according to appendices XB in Pharmacopoeia of the People's Republec of China(2010 ed), and the results were obtained by calculating the contend chang of total tannins before and after combination with the casein. The results showed that the linear range was 0.051-1.02 μg for gallic acid, the average recovery rates were 99.1%, 100.3%, 101.9%, and RSDs were 2.1%, 0.8%, 2.0%, respectively. The linear range was 2.09-10.48 μg for the total tannins, the average recovery rates were 102.2%, 100.2%, 102.1%, and RSDs were 1.3%, 1.4%, 1.0%, respectively. The investigation indicated that both methods had a preferable result for methodology validation. On the other hand, the essay also researched the P. bistorta from Guizhou and Sichuan, respectively, and the results showed that the conten of gallic acid and total tannins in P. bistorta had a great difference both Guizhou and Sichuan, the gallic acid and total tannins in P. bistorta from Guiyang were 1.53, 1.37, 1.12 mg·g^-1 and 5.01, 4.87, 5.23 mg·g^-1, respectively. And gallic acid and total tannins in P. bistorta were 2.72, 3.35, 2.46 mg·g^-1 and 5.01, 4.87, 5.23 mg·g^-1 from Chengdu, respectively. A preliminary analysis on this issue was made with many factors, as far as we know, the deciding factor should be the altitude. The references showed that the best condition for P. bistorta was an elevation from 800 to 3 000 m, while, the altitude of Guiyang at range of 800 to 1 600 m and altitude at range of 1 000 to 3 000 m for Chengdu. So, we belived that altitude of Chengdu was more amenable to the efficient growth of the P. bistorta, which futher caused the contents of gallic acid and total tannins relatively higher than Guiyang. The results provide a theory basis for pharmaceutical company to select P. bistorta for producing drugs. The research revealed that those methods were rapid, simple and reproducible and could be used to determine gallic acid and total tannins in P. bistorta. However, methods were the first to be used for determine gallic acid and total tannins in P. bistorta simultaneously, these data provide a basis for the further complement and perfect about content of Chinese Pharmacopoeia.