Abietane diterpenoids and taraxerane-type triterpenes from Teucrium viscidum

Two abietane diterpenoids, named teuvismine A (1) and B (2), along with two new taraxerane-type triterpenes, named teuvisoic acid A (3) and B (4) were isolated from whole plants of Teucrium viscidum. The structures were elucidated by the analysis of HRESIMS spectroscopy and NMR spectroscopy, as well as the comparison with published data. All isolates were evaluated for their cytotoxic activities against five human cancer cell lines (HCT116, H460, HepG2, BGC823, and HeLa cells). Compound 3 showed moderate cytotoxic activities against HCT116 and H460 with IC50 values of 6.2 and 8.6 μM, respectively.