CHEMICAL CONSTITUENTS OF THE AERIAL PARTS OF Rehmannia chingii

摘要

Rehmannia Libosch. ex Fisch. et C.A. Mey. is a small genus consisting of six species (R. glutinosa, R. chingii, R. elata, R. henryi, R. piasezkii, and R. solanifolia) in the Scrophulariaceae family, endemic to China [1]. R. glutinosa is the most popular one, the rhizome of which is known as “Dihuang” and is used for a variety disorders in traditional chinese medicine [2]. So far, the presence of three main types of metabolites, including iridoid glycosides, phenylethanoid glycosides, and ionone derivatives, has been reported from Rehmannia plants [1, 2]. It is suggested that R. chingii is a sister of the rest of the other five Rehmannia species revealed by a recent genetic taxonomical study [1]. It is mainly distributed in Zhejiang Province in China, which is therefore called “Zhe-Dihuang.” Though morphologically different from R. glutinosa (Dihuang), R. chingii possesses the advantages of stress resistance [3] and bioactivities similar to that of R. glutinosa commonly used for the treatment of fever and bleeding in folk medicine [4]. However, the chemical constituents of this plant have not yet been investigated thoroughly. So far, only glucose, catapol, descaffeoyl verbascoside, and verbascoside have been reported from R. chingii [1]. Our study was therefore aimed at the investigation of the constituents of the aerial parts of R. chingii, which led to the isolation of eight compounds 1–8, all of which, except for compound 2, were isolated from this species for the first time. Compounds 1, 6, and 7 were first isolated from the Rehmannia genus.