“…Similar to compounds 1-7, the 1 H and 13 C NMR data (Tables 2 and 3) of 8 showed the tirucallan-7-ene pattern in rings A-D. 6 In combination with the molecular formula C 26 H 35 NO 3 , based on its HRESIMS, the chemical shifts of the remaining four carbons [δ C 152.5 (s), 128.2 (d), 170.5(s), and 171.5(s)] and NH suggested the presence of a maleimide ring. 8 The structures of the known compounds, 3-oxo-24,25,26,27tetranortirucall-7-ene-23(21)-lactone (9), 9 3-hydroxy-24,25,26,27-tetranortirucall-7-ene-23(21)-lactone (10), 9 β-amyrone, 10 β-amyrin, 11 24,25-epoxytirucall-7-ene-3,23-dione, 12 syringaresinol, 13 scopoletin, 14 3R-hydroxy-12-ursen-28-oic acid, 15 xylobuxin, 16 piscidinol B, 17 and β-amyrin acetate, 18 were determined by comparing their spectroscopic data with reported values. [9][10][11][12][13][14][15][16][17][18] Compounds 1-10 were evaluated for their cytotoxicity against the HL-60, SMMC-7721, A-549, MCF-7, and SW480 cell lines by the MTT method, 19 and the results are shown in Table 4.…”