[Studies on the chemical constituents of Dendrobium loddigesii rolfe]

According to IR, UV, MS and NMR spectra of the compounds isolated from the fresh stem of Dendrobium loddigesii Rolfe (a Chinese medicine), 3 constituents were identified. They are shihunidine, shihunine and dendrophenol (4,4'- dihydroxy-3,3',5-trimethoxybibenzyl). Chemical reactions showed that shihunidine was derived from shihunine during isolation. Shihunidine and shihunine were shown to be inhibitors of Na+, K+-ATPase of the rat kidney.