Informatics and Computationally Assisted Discovery of Anti-Inflammatory Diterpenoids from Isodon rubescens

Diterpenoids occupy a valuable region of the natural products diversity space with wide ranges of bioactivities and complex structures, providing potential applications for the development of therapeutics. Five new abietane-type diterpenoids salvonitin B (1), salvonitin C (2), prionoid G (3), prionidipene F (4), viroxocin B (5), one new totarane-type diterpenoid plebedipene E (6) and one new sempervirane-type diterpenoid hispidanol C (7) were isolated from Isodon rubescens (I. rubescens). Their structures were established by spectroscopic analysis, electronic circular dichroism (ECD) calculations, and X-ray diffraction analysis. In the evaluation of bioactivities, compound 4 (10 μM) increased cell viability (0.872 ± 0.157) in lipopolysaccharide-induced RAW 264.7 cells.