Chemical Constituents from the Stems of Dendrobium denneanum (II)

Dendrobium denneanum is a traditional Chinese medicine mainly used for its antitumor, antioxidation, and hypoglycemic effects. The systematic phytochemical studies of D. denneanum were carried out for a comprehensive understanding of the plant. This study isolated ten compounds from chloroform and n-butanol fractions of dried stems of D. denneanum by silica gel column chromatography and preparative HPLC. On the basis of spectroscopic data, their structures were identif ied as cumarin(1), moscatin(2), thymidine(3), trans-syringin(4), dihydrosyringin(5), 2,4,6-trimethoxyphenol-1-O-β-D-glucopyranoside(6),(+)-syringaresinol-O-β-D-glucopyranoside(7), 3-hydroxy-1-(4-hydroxy-3,5-dimethoxyphenyl)-2-[4-(3-hydroxy-1-(E)-propenyl)-2,6-dimethoxyphenoxy] propyl-7-O-β-D-glucopyranoside(8), picraquassioside C(9) and citrusin B(10). Among them, 3- 10 were isolated from this plant for the fi rst time. Fig 1, Ref 24