ABSTRACT
The objective of this work was to explore the content and composition of aristolochic acid compounds in Chinese medicinal materials containing toxic aristolochic chemicals, so as to ensure the safety of these medicinal materials and their related products. Nine Chinese medicinal materials were selected for study, including the tuber of Aristolochia cinnabarina, the herbs of Asarum forbesii, the stems of Aristolochia manshuriensis., the fruits of Aristolochia debilis, the roots of Aristolochia debilis, the stems and leaf of Aristolochia debilis, the herbs of Aristolochia mollissima, the roots of Aristolochia fangchi, and the roots of Asarum heterotropoides var. mandshuricum. The aristolochic acid components in the nine Chinese medicinal materials were analyzed by high performance liquid chromatography-quadrupole time of flight mass spectrometry (HPLC-Q-TOF-MS) combined with high performance liquid chromatography diode-array detection. The separation was performed on an Agilent ZORBAX SB-Aq column (250 mm×4.6 mm, 5 μm) with gradient elution using a mobile phase consisting of acetonitrile and 0.2% acetic acid. ESI positive ion mode MS was used to investigate the ionization pathways of aristolochic acid Ⅰ, Ⅱ, Ⅲa, Ⅳa, Ⅶa, and aristololactam Ⅰ, Ⅱ using seven reference standards, and the structures of the components with UV spectrasimilar to those of the seven reference standards in the selected medicinal materials were qualitatively analyzed by following the investigated ionization pathways. The identified aristolochic acid components were quantified using an external standard method by HPLC-UV with detection at 254 nm. Twenty-two aristolochic acid components including 11 aristolochic acids and 11 aristololactams were identified from the nine selected medicinal materials; 15 aristolochic acids were found in the tuber of Aristolochia cinnabarina and the roots of Aristolochia debilis, followed by 14 aristolochic acids in the fruits of Aristolochia debilis and the stems of Aristolochia manshuriensis. The greatest content of aristolochia components was found in the tuber of Aristolochia cinnabarina and the stems of Aristolochia manshuriensis, ranging from 8.91 mg·g-1 to 13.40 mg·g-1, and the least amount was in the herbs of Asarum forbesii, at less than 0.10 mg·g-1 and containing only two aristolochia components. This study systematically explored the quantity and composition of aristolochic acid components in selected Chinese medicinal materials believed to contain toxic aristolochic compounds, providing a basis for follow-up studies on the toxicity of these substances that can lead to safety standards for their use.
ABSTRACT
We have developed a new method using HPLC-CAD (charged aerosol detector) for the quantitative analysis of cyclovirobuxine D and related substances in the API of Huangyangning tablets. The related substances were further studied by HPLC-Q-Exactive coupled with hybrid quadrupole-orbitrap mass spectrometry. A HILIC column of XBridge Amide (4.6 mm×250 mm, 5 μm) was used, and the mobile phase was composed of acetonitrile and 100 mmol·L-1 ammonium formate (85∶15), which was adjusted to pH 2.8 with formic acid. Isocratic mode elution was adopted at a flow rate of 1.1 mL·min-1. The column temperature was set at 30 ℃. For CAD, the temperature of atomization and gas pressure were respectively set at 35 ℃ and 62.2 psi. This method detected and quantified five related substances to cyclovirobuxine D. The results showed that the LOD and LOQ of cyclovirobuxine D was 12.588 ng and 28.323 ng, respectively with an average recovery of 95.74% (RSD = 1.79%, n = 6). The content of cyclovirobuxine D in 12 batches of API samples provided by three manufacturers was from 79.94% to 88.49%, with an average value of 82.20%. The total content of the five related substances was from 15.99% to 22.15% with an average value of 20.10%, using an external standard method with cyclovirobuxine D as the reference and according to the CAD uniform response to non-volatile substances. The newly developed HPLC-CAD method has advantages in terms of the comprehensiveness of signals from Buxus alkaloids without UV absorption and with high sensitivity to its trace-related substances; the method yields good separation between the components and is compatible with mass spectrometry. It is applicable for the accurate quantitative analysis of main components and related substances in the API of Huangyangning tablets.