New alkaloids from the stem bark of Cinnamomum bejolghota

Three new alkaloids, 3,4-bis(3,4-dimethoxyphenyl) pyridine (1), 1-(4-hydroxybenzyl)− 6-hydroxyisoquinoline) (2), and 4-(3,4-dimethoxyphenyl)− 2-methyl pyridine (3) along with six known compounds, spathulenol (4), 5,7-di-O-methyl-3′,4′-methylenedioxyflavan-3-ol (5), 3,4-dimethoxycinnamyl alcohol (6), 3,4-dimethoxycinnamaldehyde (7), veratric acid (8) and veratraldehyde (9), were isolated from the stem bark of Cinnamomum bejolghota (Buch.-Ham.) Sweet. Their structures were elucidated based on the interpretation of spectrometric and spectroscopic data (HRESI-MS, 1D- and 2D NMR) and by comparison with literature data for known compounds. Compounds 1–5 were tested for their cytotoxic activities against four human cancer cell lines (KB, MCF-7, HepG-2, and SK-LU1). Compound 1 showed moderate activity against KB, MCF7, HepG2 and SK-LU-1 cell lines with IC50 values ranging from 31.1 to 45.9 µM, while compounds 2–4 were inactive on all tested cancer cell lines up to a concentration of 128 μM and flavanol 5 showed a very weak cytotoxic activity.