Japonins A–D, cyathane diterpenoids with neurite outgrowth-promoting activity isolated from Onychium japonicum using NMR and MS/MS-based molecular networking

Abstract

Guided by MS/MS-based molecular networking strategy, four new cyathane diterpenoids japonin A–D (1–4), together with the known analogues (5 and 6), have been isolated from aerial parts of Onychium japonicum. The structures of the new compounds were elucidated through a combination of NMR and MS experiments. Through single-crystal X-ray diffraction analysis, and comparison of experimental and calculated computational electronic circular dichroism (ECD) spectra, the absolute configurations of compounds 1–4 were determined. The new compound 1 showed promoting effects on the differentiation of PC12 at a concentration of 40 μM.