Objective. To establish a method for simultaneous determination of liquiritin, liquiritigenin, and isoliquiritinin glycyrrhizin using hydrogen nuclear magnetic resonance quantitative technology (¹H-qNMR). Methodology. Deuterated dimethyl sulfoxide was used as the solvent, and dichloromethane was used as the internal standard. The probe temperature was 298.0 K, the pulse sequence was Zg30, the number of scans was 16, and relaxation delay (D1) was 10 s. Quantitative characteristic signal peaks were δ 4.891∼4.878 ppm, δ 8.187∼8.172 ppm, and δ 6.790∼6.776 ppm for liquiritin, isoliquiritin, and liquiritigenin, respectively. Results. The experimental result showed that the content of flavonoids in Licorice, from Chifeng, Inner Mongolia, was the highest. Conclusion. In this study, a new method for determination of three flavonoids in Licorice using ¹H-qNMR was established. This experimental method has the advantages of accuracy, efficiency, and economy. It lays a foundation for the study on the determination of flavonoids content in licorice by proton nuclear magnetic resonance spectroscopy.

中文翻译：

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1H-qNMR定量分析甘草中的黄酮类化合物

客观。建立氢核磁共振定量技术( ¹ H-qNMR)同时测定甘草苷、甘草苷和异甘草苷的方法。方法论。以氘代二甲亚砜为溶剂，二氯甲烷为内标。探头温度为298.0 K，脉冲序列为Zg30，扫描次数为16，弛豫延迟（D 1）为10 s。甘草素、异甘草素和甘草素的定量特征信号峰分别为δ 4.891∼4.878 ppm、δ 8.187∼8.172 ppm 和δ 6.790∼6.776 ppm。结果. 实验结果表明，内蒙古赤峰甘草中黄酮类化合物的含量最高。结论。^{本研究建立了1} H-qNMR测定甘草中三种黄酮类化合物的新方法。该实验方法具有准确、高效、经济等优点。为质子核磁共振光谱法测定甘草中黄酮类化合物含量的研究奠定了基础。