A Simple and Rapid High-Performance Liquid Chromatography Method for Preparation and Content Detection of the Mainly Numbing Taste Substances of Zanthoxylum bungeanum Maxim

Abstract As the characteristic numbing taste substances, hydroxyl-α-sanshool (HAS) and hydroxyl-β-sanshool (HBS) were considered vital indicators to evaluate the quality of Zanthoxylum bungeanum Maxim. However, it is very difficult to obtain their high-purity monomers individually, as the only difference between HAS and HBS is that C-6 cis-trans isomerism. In our study, a simple and rapid Ag +-HPLC method was developed to pure the standard chemicals of Z. bungeanum with numbing taste, and 1H NMR and 13C NMR were employed to determine the purity and structure. Moreover, an HPLC method was established to determine the content of numbing taste components of 16 varieties of Z. bungeanum from different regions. The analytical methods were validated for accuracy, precision, and linearity, respectively. The validated method was accurate (spiked recoveries 0.94–1.10), precise in terms of peak area (intra-day RSDs <1.25% and inter-day RSDs <1.61%), and linear (r2 ≥ 0.999). It was found that there were significant differences in the content of HAS and HBS among different types of Z. bungeanum, with HAS content ranging from 60.06 ± 1.14 to 164.13 ± 3.28 mg/g and HBS ranging from 7.81 ± 0.36 to 21.11 ± 0.75 mg/g. The RSDs of HAS range were 1.73–3.80% and that of HBS range 2.03–4.73% (RSDs ≤5%), which indicated that the measurements of HAS and HBS were reliable.