Li_2020_Phytochemistry_183_112593

The roots of Euphorbia fischeriana known as "Langdu" in traditional Chinese medicine have been used for the treatment of tuberculosis in China. Through a bioactive phytochemical investigation of the roots of E. fischeriana, 15 diterpenoids were obtained by various chromatographic techniques. On the basis of wide spectroscopic data, including NMR, UV, IR, HR-ESI-MS, ECD and X-ray crystallography, all of the isolated compounds were elucidated to be ent-abietane diterpenoid analogs, including undescribed eupholides A-H and seven known diterpenoids. In the bioassay for anti-tuberculosis, eupholides F-H moderately inhibited the proliferation of Mycobacterium tuberculosis H37Ra, with the MIC determined to be 50 M. Furthermore, eupholides G, ent-11alpha-hydroxyabieta-8(14), 13(15)-dien-16,12alpha-olide, and jolkinolide F significantly inhibited the lyase activity of human carboxylesterase 2 (HCE 2), with IC(50) values of 7.3, 150, and 34.5 nM, respectively.