RESUMEN
Objective: To investigate the phenanthrenes from chloroform fraction of Dendrobium chrysanthum. Methods: Several chromatographic methods such as Sephadex LH-20 and semi-preparative HPLC were applied to isolating and purifying compounds from the antihyperglycemic chloroform fraction of D. chrysanthum. Results: The structures were identified on the basis of physicochemical properties and spectroscopic data. Four compounds were isolated and identified as 2, 5-dihydroxy-4-methoxy- 9, 10-dihydrophenanthrene (1), 2, 4-dihydroxy-5-methoxy-9, 10-dihydrophenanthrene (2), 2, 4, 5-trihydroxy-9, 10-dihydrophenanthrene (3), and loddigesiinol A (4). Conclusion: Compound 2 is a new phenanthrene, named as chrysanthin A. Compounds 1, 3, and 4 are isolated from D. chrysanthum for the first time.