Studies On The Chemical Constituents And Bioactivities Of Dendrobium Nobile And Two Species Of Fissistigma Genus

Dendrobium nobile is not only an ornamental but also a medicinal plant.Many farmers grow D.nobile as an ornamental plant in Hainan.However,after its use as an ornamental plant becomes redundant,the stems and flowers of D.nobile are discarded as rubbish.To add value for D.nobile,an investigation of active constituent from these stems was explored.The investigation of antifungal and cytotoxic compounds from D.nobile led to the isolation of 17 new compounds and 46 known compounds.Among of them,the main constituent is phenanthrene.In addition,the constituent contains lactones and glycosides.1 and 2,34 and 35,36 and 37 were isolated as three pair of enantiomers by chiral HPLC.The absolute configurations of them were determined by comparing their experimental and calculated electronic circular dichroism(ECD)spectra or X-ray crystallographic analysis.The absolute configurations of 3 and 32 were determined by X-ray crystallographic analysis.Compounds 1 and 2 showed moderate inhibitory effects on HeLa,MCF-7 and A549 cells with IC50 values of 9.8,9.4,and 9.9 μM.Compounds 17-21,39,41,43,53 and 54 exhibited broad spectrum antifungal activitiy against these phytopathogenic fungi.Fissistigma oldhamii are widely used in traditional medicine for the treatment of arthritis.Hainan is prone areas of the arthritis diseases,especially rheumatoid arthritis.In order to search for new natural anti-RA products from two species of Fissistigma genus,an investigation of active constituent from these species was explored.The investigation of anti-RA compounds from two species of Fissistigma genus led to the isolation of 133 compounds.17 new compounds were isolated from the stems of F.oldhamii and 5 new compounds were isolated from the stems of F.maclurei Merr.Among of them,the main constituent is sesquiterpenes and alkaloids.Compound 64 contains an uncommon five-membered ether ring.Compounds 65,67,68 and 70 were unusual norisoprenoids.The inhibitory activities of most of the compounds against synoviocytes were evaluated.The ethanol extract exhibited inhibitory activity on synoviocytes.Compounds 72 and 73 represents the first example of ene(6→7)-abeo-6-one sesquiterpene.Compounds 72 and 73 exhibited potent inhibitory activity on synoviocytes,with IC50 values of 1.0 and 1.2 μM.Compounds 65,67,68,70,71,81,87-89,167 and 183 exhibited moderate inhibitory activity on synoviocytes.Structure-activity relationship indicated that the 6-one was important for anti-RA activity.In addition,the mechanism study of compound 72 was explored.