Four new fluorenone alkaloids and one new dihydroazafluoranthene alkaloid from Caulophyllum robustum Maxim

Four new fluorenone alkaloids, caulophylline A-D (1–4), and one new dihydroazafluoranthene alkaloid, caulophylline E (5) were isolated from the roots of Caulophyllum robustum Maxim. Their structures were elucidated by spectroscopic analysis. Among the isolated alkaloids, Caulophylline E showed good scavenging effects against DPPH radical with IC50 of 39 μM.

Graphical abstractFour new fluorenone alkaloids, caulophylline A-D (1–4), and one new dihydroazafluoranthene alkaloid, caulophylline E (5) were isolated and identified from the roots of Caulophyllum robustum Maxim.Figure optionsDownload full-size imageDownload as PowerPoint slide