A phytochemical study on the rhizomes of Cimicifuga foetida resulted in the isolation of two new cycloartane triterpenoids (1 and 2), eight new cycloartane glycosides (3–10), and six known cycloartane glycoside analogues (11–16). The structures of 1–10 were determined by application of spectroscopic methods, with the absolute configuration of 1 determined by X-ray crystallography. Compounds 1–6, as three pairs of epimers at C-10 and C-24, belong to a seven-membered-ring variant of 9,10-seco-9,19-cycloartane triterpenoids, and glycosides 3–10 were found to be 3-O-β-d-xylopyranosides. The cytotoxicity of the isolates was evaluated against five selected human tumor cell lines, and the known compounds 15 and 16 showed cytotoxicity against the hepatocellular carcinoma SMMC-7721 cell line with IC50 values of 5.5 and 6.3 μM, respectively.

•Seven compounds were obtained from the genus Echinogorgia for the first time.•New compound 1 was elucidated by spectroscopic and chemical calculation methods.•The chemotaxonomic importance of the isolates was discussed.Three guaiane-type sesquiterpenoids (1−3) and five steroids with 3β-hydroxy-5-en-7-one moiety (4−8) were obtained from gorgonian Echinogorgia sassapo reticulata collected from the South China Sea. Among them, new compound 1 was identified as (1S,5S,8S)-8-methoxy-menelloide B by spectroscopic methods including IR, HRESIMS, 1D and 2D NMR, and ECD spectra. All compounds except for 3 were obtained for the first time from the genus Echinogorgia. The chemotaxonomic significance of these compounds was summarized.

A continuing phytochemical study on the semi-mangrove plant Hibiscus tiliaceus yielded two new tetracyclic triterpenoids (3β,24S)-19(10→9)-abeo-8α,9β,10α-eupha-5,25(26)-dien-3,24-diol (tiliacol A, 1), and (3β,23Z)-19(10→9)-abeo-8α,9β,10α-tircalla-5,23-dien-3,25-diol (tiliacol B, 3), together with one known analog (2). Their structures were elucidated on the basis of extensive spectral analyses (MS, IR, 1D NMR and 2D NMR) and comparison with literature compounds. Compound 2 showed potent cytotoxicity against both P388 and HeLa cells with IC50 values of 11.2 μmol/L and 11.5 μmol/L, respectively.Two new tetracyclic triterpenoids (3β,24S)-19(10→9)-abeo-8α,9β,10α-eupha-5,25(26)-dien-3,24-diol (tiliacol A, 1), and (3β,23Z)-19(10→9)-abeo-8α,9β,10α-tircalla-5,23-dien-3,25-diol (tiliacol B, 3), together with one known analogue (2), were isolated from Hibiscus tiliaceus. Compound 2 showed potent cytotoxicity against both P388 and HeLa cells with IC50 values of 11.2 μmol/L and 11.5 μmol/L, respectively.