•Four sesquiterpenes and three triterpenes were isolated from Scorzonear divaricata.•Their structures were elucidated by spectroscopic data and X-ray crystallography.•A tirucallane triterpene showed cytotoxic activity against four tumor cell lines.•Two sulfated guaiane sesquiterpenes showed activity against ABTS cation radicals.•Sulfated guaianes occur mainly in the Lactuceae tribe of Asteraceae family.A sulfated guaiane sesquiterpene lactone, an unusual pyridinium alkaloid with a sulfated guaiane sesquiterpene lactone nucleus, an amino conjugate of a sulfated guaiane sesquiterpene lactone, a bisabolane sesquiterpene, three tirucallane triterpenes, and six known compounds, were isolated from roots of Scorzonera divaricata. Their structures and absolute configurations were established based on chemical and spectroscopic methods, X-ray single crystal crystallography, and also by comparison with experimental and calculated ECD spectra. One of the tirucallane triterpenes exhibited significant cytotoxic activities against four human cancer cell lines (HL60, HeLa, HepG2, and SMMC-7721) in vitro. Two of sulfated guaiane sesquiterpenoids also exhibited antioxidant activities by scavenging ABTS cation free radicals. Tirucallane-type and dammarane-type triterpenes were not previously known in the genus Scorzonera. The study suggests that sulfated guaiane-type sesquiterpenoids are a valuable marker for systematic chemical studies in the Lactuceae tribe of the Asteraceae.Seven sesquiterpenes and triterpenes were isolated from Scorzonear divaricata. Structures were elucidated by spectroscopic data and X-ray crystallography. Their cytotoxic and antioxidant activities were assessed.

Seven oleanane-type triterpenes and two 8-O-4′-neolignans, along with five known compounds (three 28-noroleanane-type triterpenes, one sarratane triterpene, and one neolignan), were isolated from roots of Nannoglottis carpesioides. Their structures were elucidated by spectroscopic methods, including 1D and 2D NMR, HRMS, and CD. The absolute configurations of two triterpenes were determined by experimental and calculated circular dichroism (CD) and optical rotation values. Ten compounds were evaluated for their cytotoxicity against human promyelocytic leukaemia (HL-60) and human hepatoma (Hep-G2) cells using the MTT assay. The antioxidant activities of these compounds were assessed by ABTS radical-scavenging assays. Among the tested compounds, three compounds exhibited moderate radical-scavenging activity against ABTS+, with IC50 values of 22.4, 17.4, and 23.2 μM, respectively.Graphical abstractSeven oleanane-type triterpenes and two 8-O-4′-neolignans, together with five known compounds, were isolated from the roots of Nannoglottis carpesioides (Maxim.) and the cytotoxic and antioxidant activities of ten compounds were assessed.Highlights► Phytochemial and bioactivity study of Nannoglottis carpesioides. ► Seven triterpenes and two neolignans are reported. ► Three compounds exhibited moderate antioxidant activity. ► Fourteen compounds isolated are reported in the genus Nannoglottis. ► The study supports the chemosystematic position of Nannoglottis in Astereae.

Six new sesquiterpene lactones, scorzoaustriacoside (1), scorzoaustriacin (2), scorzoaustriacin 3-O-β-d-glucoside (3), 4-epi-dihydroestafiatol (4), 14-isovaleroxyscorzoaustricin (5), and 14-isovaleroxyscorzoaustricin sulfate (6), along with five known guaianolides, were isolated from an acetone extract of the roots of Scorzonera austriaca. The structures of the new compounds were elucidated mainly by interpretation of their 1D and 2D NMR and HRMS data. Several isolates obtained in this investigation were evaluated against a small panel of cancer cell lines.

Five new modified eremophilane-type sesquiterpenes (1−5), including three norsesquiterpenes (1−3), and one new monoterpene (6) were isolated from the aerial parts of Parasenecio deltophylla. Their structures were established on the basis of HRMS and NMR methods. The cytotoxicity of compounds 1−4 and 6 against selected cancer cell lines, including human promyelocytic leukemia (HL-60) and human hepatoma (Hep-G2), was evaluated. Antioxidant activities of these compounds were assessed by ABTS and DPPH methods.

Four new compounds, a noreudesmanolide (1), a guaianolide (4), and acetylenes (7–8), together with 16 other known compounds, were isolated from Ajania przewalskii. The novel sesquiterpenolide (1) possesses a rare carbon skeleton. Acetylation of 1 gave 1a. New compounds were elucidated as 1β-hydroxyl-2-noreudesm-4(15)-en-5α,6β,7α,11αH-12,6-olide (1), 1β-acetoxyoxyl-2-noreudesm-4(15)-en-5α,6β,7α,11αH-12,6-olide (1a), 8α-angeloyloxyl-3α,4α-dihydroxyguaia-1,9,11(13)-trien-6,12-olide (4), (E)-3β,4α-dihydroxyl-2-(2′,4′-hexadiynylidene)-1,6-dioxaspiro[4,5]decane (7) and 2-hydroxyl-2-[(E)-1α,2β,3-trihydroxyl-3-nonaene-5,7-diyne]-4H-pyran (8), by chemical and spectroscopic methods, including HRESIMS, 1D and 2D NMR. Cytotoxicity of nine compounds was assessed by their effects on selected cancer cell lines, K562, K562/ADM, BGC-823, and Hep-G2 cells. Phenolic acid 12 exhibited strong activity against K562 and K562/ADM cells and sesquiterpenolide 3 strong activity against K562/ADM cells. Radical-scavenging activities of 12 compounds, the mixed solvent extract (petrol ether–ether–methanol = 1:1:1), and the n-butanol extract were determined by ABTS and DPPH radical-scavenging assays. Phenols and coumarins (11–16), MSE, and n-BE displayed significant antioxidation (IC50 < 20 μg/ml).

The root of Scorzonera austriaca has been used in indigenous cuisines as a delicious food and in the Tibetan traditional medicine in northwestern China. Two novel dimeric guaianolides linked by a carbon–carbon bond with a rare carbon skeleton, termed biguaiascorzolides A (1) and B (2), respectively, have been isolated from roots of S. austriaca. Acetylation of 1 gave 1a. The structures of 1, 1a and 2 were characterised by HR-ESI-MS, EI-MS, UV, IR, and 1D- and 2D-NMR techniques (1H and 13C NMR, 1H-1H COSY, HMQC, HMBC, and NOESY experiments). The cytotoxicity of 1a was assayed against selected cancer cell lines, including the human erythroleukaemia adriamycin-resistant subline (K562/ADM) and human stomach carcinoma (MGC-803) cell lines. Compound 1a exhibits a moderate activity against K562/ADM cell lines (IC50 39.8 μm) and is inactive towards MGC-803 cell lines.

•47 compounds were isolated from Ajania salicifolia.•34 compounds were first reported from the genus Ajania.•Chemotaxonomic relationship between A. salicifolia and the genus Ajania was discussed.•Phenolics and sesquiterpenoids could be considered as chemotaxonomic markers for genus Ajania.Forty-seven secondary metabolites were isolated from Ajania salicifolia (Mattf.) Poljak, including eight sesquiterpenoids, two diterpenoids, three triterpenoids, four steroids, three flavonoids, five coumarins, five lignans, nine phenylpropanoids, five other phenolic compounds, and three acetylenes. Their chemotaxonomic significance within the genus Ajania (the tribe Anthemideae) of the family Asteraceae is discussed.