Ecdysteroids analogues

Ecdysteroids suffer a number of disadvantages for applied purposes because they are chemically complex, environmentally and metabolically unstable and far too costly to isolate or synthesise in large amounts [150], Non-steroidal ecdysteroid analogues have greater potential for application in these respects. Further if such compounds are demonstrated to interact with the ecdysteroid-binding site of the EcR/USP complex, then analogues within these classes of compounds can be used to extend QSAR studies. 

Taken together these data indicate that different insect species are susceptible to ecdysteroid analogues to differing extents. This may go some way to explaining why phytoecdysteroid-containing plant species possess different ecdysteroid profiles. 

The effect of a few ecdysteroids and the BAHs, RH5849 and RH5992, on cell density of the cell lines Cl8+ and C18R were determined [194], All compounds had similar effects, but C18R was 10-100-fold less sensitive to the ecdysteroid analogues. It was not reported if these cell lines metabolise ecdysteroids. The activities with the Cl8+ cells were 20E (EC50 = 6 x 10 8M), Ino (4 x 10 7M), MaA (5 x 10 8M) and MuA (6 x 10 9 M). 

From the observation that the common shore crab (Carcinus maenas, Crustacea, Decapoda) rejects ecdysteroid-containing food, Tomaschko et al. [206] developed an in vivo oesophagus dilation assay, capable of comparing ecdysteroid analogues 20E (EC50 = 1.8 x 10 jVI) and 20E22AC (4.6 x 10 4M). 

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