Isolation And Structural Modification Of 20-hydroecdysone

The phytoecdysteroids are a broad group of polyhydroxysteroids found in various species of plants and close in structure and biological action to ecdysteroids in insects and crustaceans. Their structural characters are the cis-A/B-steroids and the 14 α-hydroxy-â–³⁷ -6-ketones. 20-hydroecdysone is one of the two popular representatives.From the total phytoecdysteroids in Cyanotis arachnoidea C.B.Clarke, 4 chemical constituents were isolated by various chromatographic methods .On the basis of analysis of NMR data and measuring of physico-chemical property, their structures were identified as 20-hydroxyecdysone(a) , ajugasterone C (b) , 20-hydroxyecdysone 2-acetate (c) , 20-hydroxyecdysone 3-acetate(d).In order to explore the relationship of structure and activities and find some compounds with good pharmacological activities, we try to do the structure modification of 20-hydroxyecdysone isolated and prepared by chromatography on silica gel column. According to the functional groups characteristic of 20-hydroxyecdysone, we try to use several methods to vary the numbers of hydroxyl group at different positions in the ecdysteroid skeleton. In this thesis 15 target compounds were synthesized. Most of the compounds were identified by ¹HNMR, ¹³CNMR and MS.20-hydroxyecdysone and 8 derivatives were examined for their effects on the NGF-mediated neurite outgrowth from PC12D cells to evaluate their NGF-potentiating activities. The acetonide derivatives have the significantly good activities.