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Simple and Fast Rolling Circle Amplification-Based Detection of Topoisomerase 1 Activity in Crude Biological Samples
Published on: December 2, 2022
DNA topoisomerase I inhibitory alkaloids from Corydalis saxicola
Xuanxuan Cheng1, Dongmei Wang, Lin Jiang
1School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou 510080, P. R. China.
Abstract:
Chemical studies of the Chinese herb Corydalis saxicola Bunting led to the isolation and identification of 14 alkaloids, 1-14. Seven of these compounds, 4-9 and 11, were obtained from this plant for the first time. Feruloylagmatine (7) is the first guanidine-type alkaloid to be identified in the family Papaveraceae and in dicotyledonous plants. All of the isolated compounds were assayed for inhibitory activity against human DNA topoisomerase I. A DNA cleavage assay demonstrated that these alkaloids specifically inhibit topoisomerase through stabilization of the enzyme-DNA complex. Among the isolated alkaloids, (-)-pallidine (8) and (-)-scoulerine (11) showed strong inhibitory activities toward topoisomerase I that were comparable to camptothecin, a typical topoisomerase I inhibitor. A preliminary structure-activity relationship study suggested that the quaternary ammonium ion might play an important role in topoisomerase I inhibition by the isoquinoline alkaloids. These data indicated that DNA topoisomerase I inhibition represents probably one of the anticarcinogenic mechanisms of C. saxicola.
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