Mass spectrometry guided strategy based on feature fragment ions for guided-separation on quinoline alkaloids from root barks of Dictamnus dasycarpus / 中国中药杂志

The root bark of Dictamnus dasycarpus is one of common traditional Chinese medicines (TCMs). Quinoline alkaloids are one of the main active substances in this TCM and possess many biological activities including anti-titumor, anti-inflammation, anti-bacteria, anti-oxidation, and anti-platelet aggregation activities. In this study, eight quinoline alkaloids 1-8 were firstly separated from the root barks of D. dasycarpus. It was difficult to isolate more quinoline alkaloids from the remaining fraction 8 in D. dasycarpus by this conventional chemical separation, so the target analysis method combined LC-MS guided-separation of quinoline alkaloids from fraction 8 was established. MS/MS fragmentation patterns of eight quinoline alkaloids reference standard compounds 1-8 were studied by ultra-performance liquid chromatography-electrospary ionization-mass spectrometry (UPLC-ESI-MS/MS). Based on the feature fragment ion 200, the parent ion scan mode was established for the target analysis of quinoline alkaloids in fraction 8. Finally, 8-methoxyflindersine (9) and N-metilatanina (10) were discovered and isolated quickly from fraction 8 guided by LC-MS, and their structures were identified by NMR and MS. Among them, compound 10 was isolated from the genus Dictamnus for the first time. These results indicated that this method is not only quick and sensitive for analyzing the quinoline alkaloids, but also to effectively guided-separate this kind of alkaloids in the root barks of D. dasycarpus.

Chemical constituents from root barks of Dictamnus dasycarpus and their cytotoxic activities / 中国中药杂志

Nineteen compounds, including kihadanin D (1), obacunone (2), kihadanin A (3), kihadanin B (4), kihadanin C (5), limonin (6), evodol (7), fraxinellone (8), furo[2,3-b]quinolin-4-ol (9), preskimmianine (10), ifflaiamine (11), dictamnol (12), naringenin (13), diosmetin (14), wogonin (15), scopoletin (16), cleomiscosin A (17), apocynin (18), and methyl pyroglutamate (19), were isolated from the methanol extract of the root barks of Dictamnus dasycarpus by using various column chromatographies. Their chemical structures were extensively determined on basis of UV, IR, NMR, MS, and CD spectroscopic data analyses. Among them, 1 is a new limonoid, 9 was isolated from plant kingdom for the first time, 11, 13-14 and 17-19 were obtained from the genus Dictamnnus for the first time. Cytotoxicities of compounds 1-18 were tested, and the results indicated that 1 exhibited cytotoxicities against three human cancer cell lines MDA-MB-231, A549 and HT29 with IC₅₈ values of 16.22, 21.72 and 31.06 μmol·L⁻¹, respectively.

Preliminary establishment of integration of Alzheimer's disease and blood stasis syndrome tree shrew model and evaluation of intervention of Panax notoginseng saponins / 中国中药杂志

To establish the integration of Alzheimer's disease(AD) and blood stasis syndrome tree shrew model. Panax notoginseng saponins (PNS) was used to intervene the model to testify the stability of the model. The level of blood stasis of each group in the tree shrew model was evaluated by analyzing five traditional Chinese medicine(TCM) characterizations, four blood coagulation indexes, plasma nitric oxide (NO) level, plasma superoxide dismutase (SOD) level in each group. Hematoxylin and eosin(HE) staining was used to observe the morphological changes of brain hippocampal neuron cell of each group. Immunohistochemical staining was used to assay the ChAT and SYP levels in brain hippocampus of each group.The blood stasis characterization of the integration of disease and syndrome group was more obvious than the AD group, and that of the drug administration group was lower than that of the integration of disease and syndrome group. Aβ1-42, APP, P-Tau, ChAT and SYP level of AD group were lower than those in the blank group, which were further reduced in the model of integration of disease and syndrome. However, the administration of PNS relieved the reduction, indicating that the AD and blood stasis integration syndrome tree shrew model is stable.