Diverse diterpenoids and a triterpenoid from Euphorbia spinidens Bornm. ex Prokh

Four previously unreported diterpenoids including three ent-atisanes (1–3) and one ent-abietane (4), along with one known linear triterpenoid (5) and five known diterpenoids including four myrsinanes (6–9), and one abietane (10) have been isolated from the roots of Euphorbia spinidens Bornm. ex Prokh. The structures were determined on the basis of extensive spectroscopic analyses including HR-ESI-MS, 1D and 2D NMR and comparison of the data with those reported in the literature. Antimicrobial potential of isolated compounds were also evaluated. Guionianol B (10) showed good antibacterial activity against Staphylococcus aureus and Bacillus subtilis with MIC value of 6.25 μg/mL.