Characterization and identification of alkaloids in Phellodendri Chinensis Cortex and Phellodendri Amurensis Cortex based on UHPLC-IM-Q-TOF-MS / 中国中药杂志

A strategy combining collision cross section(CCS) prediction and quantitative structure-retention relationship(QSRR) model for quinoline and isoquinoline alkaloids was established based on UHPLC-IM-Q-TOF-MS and applied to Phellodendri Chinensis Cortex and Phellodendri Amurensis Cortex. The strategy included the following three steps.(1) The molecular features were extracted by the "find features" algorithm.(2) The potential quinoline and isoquinoline alkaloids were screened by filtering the original characteristic ions extracted from Phellodendri Chinensis Cortex and Phellodendri Amurensis Cortex by the established CCS vs m/z prediction interval.(3) According to the retention time of candidate compounds predicted by QSRR model, the chemical constituents were identified in combination with the characteristic fragment ions and pyrolysis law of secondary mass spectrometry. With the strategy, a total of 80 compounds were predicted, and 15 were identified accurately. The strategy is effective for the identification of small analogs of traditional Chinese medicine.

Application and problems of quinoline alkaloids in the treatment of COVID-19 / 西安交通大学学报(医学版)

The febrile respiratory disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has become the focus of global attention. Up to now, the infection has been continuing to spread all over the world and it is urgent to develop specific drugs for SARS-CoV-2. Finding effective and safe drugs which are already available in the market for treating coronavirus disease 2019 (COVID-19) is one of the main strategies to solve the problem in time. As quinoline alkaloids against malaria, chloroquine and hydroxychloroquine have been proved to have the anti-SARS-CoV-2 activity. Quinoline alkaloids are expected to be important drugs for the treatment of COVID-19. In this article, the research and application of chloroquine and hydroxychloroquine are reviewed from the aspects of pharmacokinetics, drug interaction, clinical research progress, treatment plan optimization and resolution of optical enantiomers. The possible problems are summarized in order to provide reference for further research and clinical application of quinoline alkaloids in the treatment of COVID-19.

Quinoline alkaloids isolated from Scolopendra subspinipes mutilans / 中草药·英文版

Objective: To study the quinoline alkaloids from the ethanol extract of Scolopendra subspinipes mutilans (SSM). Methods: The chemical constituents were isolated and purified by macroporous resin column, medium pressure preparation chromatography, and semi-preparative HPLC. Their structures were elucidated by IR, MS, and NMR experiments. Results: Three quinolone alkaloids were obtained and identified as 3-hydroxy-4-methoxyquinolin-8-yl hydrogen sulfate (1), jineol-8-sulfate (2), and jineol (3), respectively. Conclusion: Compound 1 is a new compound from SSM.

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.

Isolation of quinoline alkaloids from three Choisya species by high-speed countercurrent chromatography and the determination of their antioxidant capacity

Abstract Choisya ternata Kunth, C. ternata var. sundance Kunth and the hybrid Choisya 'Aztec-Pearl' are three related species belonging to the Rutaceae family. Ethanol extracts were prepared from the leaves of these three species and evaluated in relation to their antioxidant activity using in vitro and ex vivo models. The ethanol extracts belonging to the three species produced a very high antioxidant profile as evidenced by the DPPH radical scavenging activity, the determination of total phenolics and flavonoid equivalent. The generation of reactive species of oxygen in leukocytes stimulated with LPS was dramatically reduced when the three ethanol extracts were used. The alkaloids anhydroevoxine and choisyine were isolated from the ethanol extract of C. ternata using HEMWat (4:6:5:5) as the solvent system by means of high-speed countercurrent chromatography. This was the first time quinoline alkaloids were isolated from this species using HSCCC. These compounds were also assayed for their capacity to inhibit the generation of ROS in leukocytes stimulated by LPS and the results also suggested that they are reactive oxygenase inhibitors.

Study on alkaloids from Ervatamia hainanensis / 中草药

Objective: To study the alkaloids from Ervatamia hainanensis. Methods: The alkaloids were isolated and purified by silica gel, MCI, Sephadex LH-20 column chromatography, and semi-preparative HPLC, and their structures were elucidated by physical and spectroscopic analysis. Results: Twelve alkaloids were obtained and identified as coronaridine (1), 19-epi-heyneanine (2), 9,10-dimethoxycoronaridine (3), vobasine (4), vobasine N(4)-oxide (5), 3-oxo-19-epi-heyneanine (6), strictamine (7), deacetylakuammiline (8), pandine (9), rhazicine (10), rhazicine N(4)-oxide (11), and rhazimine (12). Conclusion: Compounds 8 and 10-12 are isolated from the genus Ervatamia Stapf for the first time, while compounds 3 and 5-7 are firstly obtained from E. hainanensis.

A new quinoline alkaloid from the roots of Dictamnus angustifolius / 中国天然药物

AIM@#To investigate the quinoline alkaloids from the roots of Dictamnus angustifolius G.Don ex Sweet (Rutaceae).@*METHOD@#The quinoline alkaloids were isolated by various column chromatographic methods and their structures were elucidated on the basis of spectral analysis.@*RESULTS@#A new quinoline alkaloid, 5-methoxylrobustine (1), along with five known quinoline alkaloids were obtained, and their structures were identified as dictamnine (2), robustine (3), isopteleine (4), γ-fagarine (5), and skimmianine (6). Cytotoxicity testing of these alkaloids showed that all of them had weak cytotoxic activities against human breast cancer cells (MCF7).@*CONCLUSION@#Compound 1 is a new quinoline alkaloid. Alkaloid 3 showed stronger anti-proliferation effect than the other alkaloids.