Preparative separation of specific triterpenoids from Inonotus obliquus based on negative-pressure cavitation extraction and high-speed counter-current chromatography

Inonotus obliquus, a famous dark brown white-rot fungus on birch trees, has remarkable anti-cancer activity due to its special triterpenpoid components. The aims of this study were to develop an efficient and integrated strategy for preparative separation of triterpenoids from Inonotus obliquus and to provide ideas for the preparation of bioactive ingredients in other complex materials. In the present study, an integrated technology of negative pressure cavitation extraction (NPCE) and high-speed counter-current chromatography (HSCCC) separation of four main triterpenoids in Inonotus obliquus was developed for the first time. Response surface methodology was used to optimize the negative pressure cavitation extraction parameters of triterpenoids from Inonotus obliquus. For the rapid and effective preparative separation of triterpenoids, the HSCCC method with Hex-ACN (1:1; v/v) system was established. The extraction yield of total triterpenoids reached 17.41 mg/g under the optimal NPCE extraction conditions. The specific four triterpenoids including 3β-hydroxy-lanosta-8, 24-diene-21-al (0.84 mg/g), Inoterpene F (1.09 mg/g), Inotodiol (2.93 mg/g), Lanosterol (1.42 mg/g) were obtained by one step separation with the purities of more than 95%. This is the first report on the preparative separation of triterpenoids from Inonotus obliquus by NPCE-HSCCC.