title: Photochemical transformation of 20-hydroxyecdysone: production of monomeric and dimeric ecdysteroid analogues.
abstract: Structural modification of 20-hydroxyecdysone (20E) based on photochemical transformation yielded dimeric ecdysteroid 7alphaH,7'alphaH-bis-[(20R,22R)-2beta,3beta,20,22,25-pentahydroxy-5beta-cholest-8(14)-en-6-one-7-yl] as a main product. Its structure was determined by detailed NMR analysis. Furthermore, two new monomeric analogues: 14-epi-20-hydroxyecdysone and 14-deoxy-14,18-cyclo-20-hydroxyecdysone were identified in addition to the earlier described 14-deoxy and 14-hydroperoxy derivatives of 20E. Formation of the specific and so far unique ecdysteroid dimer has not been observed in earlier photo-transformation studies. The transformed dimeric analogue of 20-hydroxyecdysone retained the high agonistic activity on the ecdysone receptor in the B(II)-bioassay compared with the original 20E.
authors.affiliation: Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, 16610 Prague 6, Czech Republic. harmatha@uochb.cas.cz
authors.forename: Juraj
authors.initials: J
authors.lastname: Harmatha
authors.forename: Milos
authors.initials: M
authors.lastname: Budesínský
authors.forename: Karel
authors.initials: K
authors.lastname: Vokác
mesh_terms: D000818:Animals; D002851:Chromatography, High Pressure Liquid; D019281:Dimerization; D004331:Drosophila melanogaster; D026461:Ecdysteroids / Q000031:analogs & derivatives*; D004441:Ecdysterone / Q000138:chemical synthesis* / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D008958:Models, Molecular; D008968:Molecular Conformation; D010777:Photochemistry / Q000379:methods*; D011987:Receptors, Steroid / Q000819:agonists; D013055:Spectrophotometry, Infrared; D013329:Structure-Activity Relationship
chemical_list: D026461:Ecdysteroids; D011987:Receptors, Steroid; C055469:ecdysone receptor; D004441:Ecdysterone