Euphothymifols a and B, novel bioactive bicyclic jatrophane-type diterpenoids from <i>euphorbia thymifolia</i> L

Two new 5/12 bicyclic jatrophane-type diterpenoids, euphothymifols A and B (<b>1</b>-<b>2</b>), were obtained from <i>Euphorbia thymifolia</i> L. Their structures were defined by their spectroscopic data and GIAO NMR calculations as well as their biosynthetic pathway. Euphothymifols A (<b>1</b>) and B (<b>2</b>) exhibited inhibitory activities against nitric oxide (NO) production with IC₅₀ values of 43.5 ± 1.54 <i>μ</i>M (<b>1</b>) and 56.2 ± 1.67 <i>μ</i>M (<b>2</b>) in LPS-induced BV-2 microglia cells.