Chemical investigation, dereplication studies by UHPLC-ESI-HRMSMS/molecular networking, and antiproliferative activity of <i>Symphyopappus cuneatus</i> (Asteraceae)

The chemical investigation of <i>Symphyopappus cuneatus</i> led to the isolation of a new clerodane-type diterpene, named cuneatin, besides the known flavonoids hydroxywogonin, onopordin, diosmetin, 5,6-dihydroxy-7,3`,4`-trimethoxy flavone, apigenin, luteolin, and quercetin 3-O-glycoside-7-O-ramnoside. In addition, four known clerodane-type diterpenes and two flavonoids were annotated in the dichloromethane fraction by dereplication and molecular networking. These compounds are being described for the first time in <i>S. cuneatus</i>. The hexane, dichloromethane, ethyl acetate and aqueous-methanol fractions, and the new isolated clerodane were evaluated for their antiproliferative activity against human tumour cells lines. In addition to the cytostatic effects observed for the dichloromethane and ethyl acetate fractions, the new compound cuneatin showed selective and moderate antiproliferative effect against ovarian (OVCAR-03, GI₅₀ = 13.2 µM, S.I. = 3.6), multi-resistant ovarian (NCI-ADR/RES, GI₅₀ = 17,8 μM, S.I. = 2.7) and chronic myeloid leukaemia (K562, GI₅₀ = 15.5 μM, S.I. = 3.1) cell lines.