Aromatic Rosane-type Diterpenoid with Lipase Inhibitory Effect from Euphorbia ebracteolata and Chemotaxonomic Significance of Diterpenoids

Abstract

The phytochemical investigation has been performed for Euphorbia ebracteolata, the roots of which are usually used natural medicine in traditional Chinese medicine for the treatments of tuberculosis and bacterial infection. A diterpenoid has been obtained using silica gel and ODS column chromatography. Furthermore, on the basis of widely spectroscopic data analyses, including 1D-, 2D-NMR, HR-ESIMS and ECD, the isolated compound was determined to be a rosane type diterpenoid, which possessed a rare aromatic ring. The isolated diterpenoid as a new compound was named ebraphenol E (1). The bioactivity of isolated diterpenoid (1) has been evaluated and moderate inhibitory effect on lipase (IC50 = 12.5 μM) was observed. In combination with our previous phytochemical investigations about E. ebracteolata, the chemotaxonomic significance of diterpenoids was summarized for E. ebracteolata.

GlmU inhibitor from the roots of Euphorbia ebracteolata as an anti-tuberculosis agent

“…Analysis of nuclear magnetic resonance and high-resolution mass spectrometry ( 1 H NMR, 13 C NMR, and HRMS, respectively) indicated that the isolated compounds were aromatic rosane diterpenoids. Compared with previous studies, 16–20 the chemical structure of the isolate was determined to be a series rosane type diterpenoid possessing an aromatic ring as shown in Fig. 2a .…”

“…The chemical structures were determined by the spectroscopic data analysis according to our previous work. 16,17 Especially, compound 3 was determined to be ebractenoid F, an aromatic rosane type diterpenoid, 18–20 based on 1 H NMR (CDCl 3 , 600 MHz) δ H 6.71 (1H, s), 5.86 (1H, dd, J = 17.4, 10.8 Hz), 4.96 (1H, dd, J = 17.4, 1.2 Hz), 4.89 (1H, dd, J = 10.8, 1.8 Hz), 2.64 (2H, m), 1.97 (1H, dt, J = 12.6, 3.0 Hz), 1.75 (1H, m), 1.66 (2H, m), 1.57 (3H, m), 1.44 (1H, t, J = 13.2 Hz), 1.39 (1H, m), 1.20 (1H, dt, J = 13.2, 2.4 Hz), 1.02 (3H, s), 1.01 (3H, s) (Fig. S1†), 13 C NMR (CDCl 3 , 150 MHz) δ C 151.1, 140.7, 140.4, 139.8, 127.1, 122.6, 108.9, 108.8, 39.6, 36.5, 36.4, 36.3, 34.1, 32.9, 26.9, 25.6, 22.8, 21.4, 11.4 (Fig.…”