桑枝中γ-氨基丁酸的鉴别与含量测定

Identification and quantification of γ-aminobutyric acid in Ramulus Mori by TLC and HPLC

目的：建立桑枝中γ-氨基丁酸（GABA）的鉴别及其含量测定的方法。方法以乙醇为溶剂超声提取GABA，正丁醇-冰乙酸-水（4∶2.2∶1，V/V/V）为展开剂，茚三酮为显色剂，在高效硅胶G薄层板上展开。采用HPLC法，测定γ-GABA的含量。色谱柱为ODS柱（4.6 mm×250 mm，5μm），以磷酸盐缓冲溶液（pH=6.8）-甲醇为流动相，梯度洗脱，流速1.0 ml/min，检测波长为335 nm。结果桑枝中GABA的薄层色谱图斑点清晰，分离度好。在1.006～84.504μg/ml的浓度范围内，GABA的峰面积与其浓度呈良好的线性关系，r=0.9994。结论该法简单准确，重复性好，可用于桑枝药材的质量鉴别。

Objective To establish the methods for identification and quantification ofγ-aminobutyric acid（GABA）in Ramu-lus Mori by TLC and HPLC. Methods GABA was extracted by ultrasonic method with ethanol as solvent. The sample was applied on an efficient silica gel G plate with n-butanol-acetic acid-water（4∶2.2∶1）as the developing system,and ninhydrin was used as chromog-enie reagent. The content ofγ-GABA was determined by HPLC. The separation was carried out on a ODS（4.6 mm × 250 mm,5μm） column with phosphate buffered solution（pH=6.8）-methanol as a mobile phase with gradient elution,flow rate was 1.0 ml/min,the de-tection wavelength was 335 nm. Results The TLC spots of GABA in Ramulus Mori were clear with good separation. The assay of GA-BA was linear in the range of 1.006-84.504μg/ml and correlation coefficient was 0.9994. Conclusion The methods are simple,ac-curate and reproducible which are valuable to identify Ramulus Mori.