Three new paeonidanin-type monoterpene glycosides, named suffrupaeonidanins A -C, were isolated as minor components from the root cortex of Paeonia suffruticosa Andr. Their structures were elucidated by a combination of 1D-and 2D-NMR, and mass spectral techniques.Introduction. -Paeonia, the only genus in the Paeoniaceae family, has ca. 35 species distributed in the warm temperate regions of the Eurasia mainland and America [1]. The root cortex of Paeonia suffruticosa Andr. is a famous traditional Chinese medicine known for its immunoregulatory [2], anticoagulant, anti-inflammatory, analgesic, and sedative activities, and its efficacy in the treatment of cardiovascular diseases and dysmenorrhea [3]. Previous phytochemical investigations of P. suffruticosa resulted in the isolation of phenolic constituents [4], monoterpenes [5], flavones [6], triterpenes [7], and resveratrol trimers [8]. The plants of Paeonia species are rich in biologically active monoterpene compounds possessing a unique cage-like pinane skeleton. To the best of our knowledge, ca. 22 monoterpene glycosides were isolated from P. suffruticosa, for example, paeoniflorin, oxypaeoniflorin, and benzoylpaeoniflorin [9]. Paeonidanins A and B, whose aglycon structure is different from the common monoterpenes in this genus, were isolated from Paeonia albiflora and showed strong inhibitory activity on nitric oxide production in lipopolysaccharide-activated N9 microglia [10]. With the aim to isolate structurally interesting and bioactive monoterpene glycosides, we investigated the alcohol extract of P. suffruticosa. This led to the isolation of three new paeonidanin-type glycosides, suffrupaeonidanins A -C 1 ) (1 -3, resp.; see Fig. 1). Herein, we describe the isolation and structure elucidation of these new paeonidanin-type glycosides.