RESUMO
Starting from (22R,23R)-2α,3α,22,23,26-pentahydroxy-5α-cholestan-6-one 26-hemisuccinate, conjugates of 28-norcastasterone with horse radish peroxidase and bovine serum albumin were prepared. The latter conjugate was injected into rabbits; produced polyclonal antibodies were used to quantitate 6-keto-brassinosteroids. The newly developed analytical system was used in combination with two other immunoenzymatic assays for brassinosteroids to determine individual compounds of this series. In addition, a direct method of brassinosteroid analysis was proposed. It has the advantage of requiring no sample pretreatment steps such as extraction with organic solvents and chromatography.
Assuntos
Brassinosteroides/análise , Camomila/química , Ensaio de Imunoadsorção Enzimática , Animais , Bovinos , Peroxidase do Rábano Silvestre/química , Peroxidase do Rábano Silvestre/metabolismo , Cavalos , Conformação Molecular , Coelhos , Soroalbumina Bovina/química , Soroalbumina Bovina/metabolismoRESUMO
Treatment of ecdysteroids with excess of TBAF in THF was shown to proceed with stereoselective oxidation at the 9alpha position of the carbon skeleton. The stereochemistry of the products was confirmed by X-ray analysis. Using this method, 9alpha-hydroxyecdysteroids were obtained in good yield. The results open a route to novel type of natural and modified steroids that are difficult to access otherwise.
