Qualitative and quantitative analysis of aristolochic acid components in nine Chinese medicinal materials containing toxic aristolochic substances / 药学学报

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.

Effects of short-chain acyl-CoA dehydrogenase on hypertensive vascular remodeling / 中国病理生理杂志

AIM:To investigate the changes of short-chain acyl-CoA dehydrogenase(SCAD)in hypertensive vascular remodeling and to explore the relationship between SCAD and vascular remodeling in hypertension.METHODS:The spontaneously hypertensive rats(SHR;24 weeks old)and Wistar rats(24 weeks old)were used as experimental con-trol groups.The SHR and Wistar rats of 16 weeks old were trained by swimming as experimental groups.The systolic pres-sure was measured periodically.The thickness of vascular wall and the diameter of the vascular lumen were measured.The contents of ROS and ATP,the enzyme activity of SCAD, and the expression of SCAD at mRNA and protein levels in the aorta were determined.The free fatty acid in the serum and aorta was also measured.RESULTS:Compared with Wistar group,the diameter of vascular lumen decreased in SHR group.The thickness of vascular wall,the ratio of vascular wall and the diameter of vascular lumen,and the blood pressure in SHR group were increased significantly(P<0.05).Com-pared with SHR group,the diameter of vascular lumen increased in SHR +swim group.The thickness of vascular wall,the ratio of vascular wall and the diameter of vascular lumen,and the blood pressure in SHR +swim group were decreased sig-nificantly.Compared with control group, the expression of SCAD at mRNA and protein levels, the enzyme activity of SCAD,and the content of ATP were decreased in SHR group.However,the free fatty acid in the serum and aorta,and the content of ROS in the aorta were increased in SHR group.The expression of SCAD at mRNA and protein levels,the en-zyme activity of SCAD,the content of ATP were increased in Wistar +swim group and SHR +swim group.However, the free fatty acid in serum and aorta,and the content of ROS in the aorta were decreased in Wistar +swim group and SHR+swim group.CONCLUSION: Decrease in SCAD expression may be associated with hypertensive vascular remodeling. Swimming training can reverse hypertensive vascular remodeling by increasing the expression of SCAD in the aorta.

Application of HPLC-ESI-ITMS in the quality control of carboxyterminal sequence confirmation for insulin and insulin chain B / 药学学报

Application of HPLC-ESI-ITMS in the quality control of carboxyterminal sequence confirmation for insulin and insulin chain B was studied. The solution of intact insulin or insulin chain B was added to the solution of carboxypeptidase P (CPP) and carboxypeptidase Y (CPY). Fractions of appropriate volume were removed at some appointed time points, acidified with the same amount of 1% formic acid to stop the digestion, and then briefly vortexed for HPLC-ESI-ITMS analysis. Mobile phase A consisted of 0.02% TFA in 98% ultra-pure water and 2% acetonitrile. Mobile phase B consisted of 0.02% TFA in 98% acetonitrile and 2% ultra-pure water. The solution used for post-column fix consisted of propionic acid and isopropyl alcohol (20 : 80, v/v). Chromatographic separation was carried out on a reversed-phase column (Zorbax Prosphere C18, 300A, 5 microm, 2.1 mm ID x 150 mm length). The molecular weights of the multiply charged ions representing consecutive truncated losses of carboxyterminal amino acids were determined by the use of HPLC-ESI-ITMS. The differences between the consecutive truncated peptides are the experimental weights of the carboxyterminal amino acid residues. The carboxyterminal amino acid residue Ala, which released from chain B of intact insulin, was confirmed in the nanomolar concentration range by analyzing the molecular weight of the truncated peptides. Another one carboxyterminal amino acid Ala was confirmed in the nanomolar concentration range of insulin chain B. In the quality control for recombinant DNA product or natural protein, the confirmation of 1 - 3 carboxyterminal amino acid residues is regarded to be up to standard. One amino acid residue of insulin or insulin chain B could be confirmed accurately in the nanomolar concentration range. The results showed that intact insulin could be directly sequenced in the quality control without separating chain B from chain A. There would be no need to separate chain A from chain B to identify carboxyterminal of intact insulin. Furthermore, the method saved us a lot of trouble from the preparation and purification of insulin chain A and chain B.

Structural characterization of chlorobenzylidine / 药学学报

<p><b>AIM</b>To study the structure and crystal forms of chlorobenzylidine.</p><p><b>METHODS</b>Karl Fischer titrimetry, FTIR, thermal analysis, single and powder X-ray diffraction were used for the studies of the structure of chlorobenzylidine and for the identification of two forms of chlorobenzylidine.</p><p><b>RESULTS</b>Chlorobenzylidine and its diastereoisomer have been studied in this article. They can be distinguished by their different melting points. Two crystal forms of chlorobenzylidine (form A and form B) have also been detected and studied. Form A was studied by single-crystal X-ray diffraction, it crystallized in the triclinic system, space group P1(-), with two formula units per cell, is monohydrate. Karl Fischer titrimetry, FTIR, thermal analysis and powder X-ray diffraction were used for identification of the two forms.</p><p><b>CONCLUSION</b>The studies of structure and crystal forms of chlorobenzylidine are very useful for the clinical research and the selection of recrystallization process.</p>