Aromatic rosane diterpenoids from the roots of Euphorbia ebracteolata and their inhibitory effects against lipase.

The bioactive chemical constituents of Euphorbia ebracteolata have been investigated in the present work using various techniques. On the basis of chromatographic methods, such as silica gel, RP C-18 column chromatography, five novel rosane type diterpenoids with an aromatic A-ring (1-5) have been isolated from the roots of Euphorbia ebracteolata. Their structures were elucidated by widely spectroscopic data, including HRESI-MS, 1D and 2D NMR. Additionally, the inhibitory effects on lipase of these isolated diterpenoids were evaluated in vitro. Compound 1 as a new diterpenoid displayed significant inhibitory effect on lipase (IC ₅₀  = 1.0 μM). And, the inhibitory kinetics has been studied fully, which determined a competitive inhibition model for compound 1 on the enzymatic activity of lipase (K _i  = 1.8 μM).
(Copyright © 2019. Published by Elsevier Inc.)