An efficient method for rapid screening of triterpenoid saponins in three Glycyrrhiza species using rapid resolution liquid chromatography quadrupole time-of-flight mass spectrometry combined with mass defect filtering.

Triterpenoid saponins, a major bioactive component of liquorice, possess high hydrophilicity and often co-occur with other impurities of similar polarity. Additionally, subtle structural differences of some triterpenoid saponins bring challenges to comprehensive characterisation. In this study, triterpenoid saponins of three Glycyrrhiza species were systematically analysed using rapid resolution liquid chromatography quadrupole time-of-flight mass spectrometry (RRLC-Q-TOF-MS) coupled with mass defect filtering (MDF). Firstly, comprehensive date acquisition was achieved using RRLC-Q-TOF-MS. Secondly, a polygonal MDF method was established by summarizing known and speculated substituents and modifications based on the core structure to rapidly screen potential triterpenoid saponins. Thirdly, based on the fragmentation patterns of reference compounds, an identification strategy for characterisation of triterpenoid saponins was proposed. The strategy divided triterpenoid saponins into three distinct classes. By this strategy, 98 triterpenoid saponins including 10 potential new ones were tentatively characterised. Finally, triterpenoid saponins of three Glycyrrhiza species were further analysed using principle component analysis (PCA) and orthogonality partial least squares discriminant analysis (OPLS-DA). Among these, 18 compounds with variable importance in projections (VIP) > 1.0 and P values < 0.05 were selected to distinguish three Glycyrrhiza species. Overall, our study provided a reference for quality control and rational use of the three species.

Structural identification and comprehensive comparison of saponin-related impurities present in the three different compound glycyrrhizin tablets.

Compound Glycyrrhizin Tablet (CGT) is a glycyrrhizin-containing (monoammonium glycyrrhizate, MAG) preparation, which has been widely used in clinical treatment of chronic liver diseases, eczema, atopic dermatitis and other conditions. However, the impurity profile of CGT has not yet been completely elucidated. In this study, eight main saponin-related impurity compounds were initially isolated and identified. Thereafter, based on the characteristic MS/MS fragmentation pathways analysis of the isolated compounds, a novel strategy for characterization and identification of saponin-related impurities was proposed. Then, a total of 41 saponin-related impurities were identified or tentatively characterized in CGTs. Furthermore, principal component analysis (PCA), Wayne diagram and heatmap analysis revealed that the process-related impurity profile in CGTs from three different manufacturers was significantly different. Overall, our findings provided additional technological support for evaluating saponin-related impurities, thereby laying a solid foundation to develop strategies for future product quality improvement.

Complete mitochondrial genome of Acrossocheilus parallens (Cypriniformes, Barbinae).

The omnivorous fish Acrossocheilus parallens (Cypriniformes, Barbinae) is endemic to China. In this paper, the complete mitochondrial genome sequence of A. parallens was firstly determined. The circle genome (16,592 bp) comprises 13 protein-coding genes, 22 tRNA genes, 2 rRNA genes and 1 control region. The overall base composition of A. parallens is 31.0% for A, 24.7% for T, 28.0% for C, and 16.3% for G, with a slight A + T bias of 55.7%. The termination-associated sequence and conserved sequence block domains were found in the control region. It has the typical vertebrate mitochondrial gene arrangement.