Systematic phytochemical investigation of Abies spectabilis

Systematical phytochemical investigations on Abies spectabilis afforded 72 chemical constituents. On the basis of physical and spectroscopic data, including 1D and 2D homo- and heteronuclear NMR experiments (heteronuclear single quantum coherence (HSQC), (1)H-(1)H correlation spectroscopy (COSY), heteronuclear multiple bond connectivity (HMBC), and nuclear Overhauser effect spectroscopy (NOESY)), and by comparison with the literature references, they were identified as 3 triterpenoids, 23 diterpenoids, 1 sesquiterpenoid, 13 flavonoids, 12 lignans, and 20 other components. Among these compounds, three were identified as new including abieta-7,13-diene-12α-methoxy-18-oic acid (1), 7α-methoxy-dehydroabietic acid (2), and 5-hydroxy-6-methyl-7,4'-dimethoxyflavone-8-O-β-D-glucopyranoside (3). These three new compounds (1-3) and all the known terpenoids (4-28) were tested for cytotoxic activities against four tumor cell lines: A549, COLO-25, QGY-25, and THP-1. However, none of them showed a positive effect (IC₅₀>100 µM).