ABSTRACT
In this study, seven bibenzyl compounds were isolated from the stem of Dendrobium nobile by silica gel, MCI column chromatographic and preparative HPLC technology. By using spectroscopic techniques including NMR and MS, these compounds were identified as 4, α-dihydroxy-3, 5, 3'-trimethoxybibenzyl (1), 4, 5-dihydroxy-3, 3', α-trimethoxybibenzyl (2), 4, 4'-dihydroxy-3, 5, 3'-trimethoxybibenzyl (3), 4, 5-dihydroxy-3, 3'-dimethoxybibenzyl (4), 4, 3'-dihydroxy-3, 5-dimethoxybibenzyl (5), 5, 4'-dihydroxy-3, 3'-dimethoxybibenzyl (6) and 5, 3'-dihydroxy-3-methoxybibenzyl (7). Compound 1 is a new compound and compound 4 was isolated from this plant for the first time.
ABSTRACT
According to the super-position principle of the reinforcement of biological activities, a series of novel E-substituted 2, 3-diaryl propenoic acyloxy phosphonate derivatives were designed and synthesized. And the structures of the target compounds were confirmed by IR, 1H NMR, 13C NMR and elemental analysis. Furthermore, the cytotoxicities of all compounds on A-549, SGC-7901 and EC-109 in vitro were evaluated by MTT assay, and some of them showed good antitumor activity. Among the active compounds, especially, the IC50 value of compound 3e was (12.7 ± 1.9) μmol x L(-1) against A-549 cells, similar to cisplatin [IC50 = (8.0 ± 1.5) μmol x L(-1)], compounds 3g and 3k had better inhibition effect on EC-109 cells growth, with the IC50 values of (9.5 ± 1.8) μmol x L(-1) and (11.5 ± 0.9) μmol x L(-1) respectively, and compounds 3i and 3k exhibited good cytotoxic property on A-549, SGC-7901 and EC-109, which were worth further investigation.