Quality consistency evaluation of commercial Prunellae Spica by integrating determination of secondary metabolites and saccharides

Abstract

Introduction: Prunellae Spica (PS) is a commonly used medicinal herb in China. Secondary metabolites and saccharides are major bioactive components of PS. However, holistic quality consistency of commercial PS is ambiguous due to lack of comprehensive evaluation methods and reliable quality control markers.

Objectives: Integrating multiple chromatographic and chemometric methods to comprehensively evaluate the holistic quality of PS.

Material and methods: Ultrahigh-performance liquid chromatography coupled with triple-quadrupole tandem mass spectrometry (UPLC-TQ-MS/MS) was applied to quantify 12 secondary metabolites of PS. High-performance liquid chromatography coupled with photodiode array/evaporative light scattering detection (HPLC-PDA/ELSD) and high-performance gel permeation chromatography (HPGPC) methods were used to characterise the saccharides. Multivariate statistical analysis was adopted to evaluate the quality consistency of commercial PS and explore the potential quality control markers.

Results: The contents of secondary metabolites and saccharides were significantly different among commercial PS. All samples could be classified into three groups with ferulic acid, protocatechualdehyde, gallic acid, ursolic acid/oleanolic acid, sucrose, p-coumaric acid, chlorogenic acid as the major contributing components responsible for the difference. The content of rosmarinic acid was correlated with that of betulinic acid, hyperposide, chlorogenic acid, rutin, caffeic acid, p-coumaric acid and glucose, whereas polysaccharides, ferulic acid, protocatechualdehyde and ursolic acid/oleanolic acid, quercetin, sucrose and majority monosaccharides were not.

Conclusion: The holistic quality of commercial PS was inconsistent. Together with rosmarinic acid, ferulic acid, protocatechualdehyde, ursolic acid/oleanolic acid, polysaccharides and sucrose might be recommended as potential quality control markers for the holistic quality control of PS.

Keywords: Prunellae Spica; holistic quality evaluation; multivariate statistical analysis; saccharides; secondary metabolites.