The mechanism of β-cyclodextrin on the 11β-hydroxylation biotransformation of steroid

In this paper, the biotransformation of 17α-hydroxypregna-4-ene-3 20-dione-21-acetate (RSA) and 17α-hydroxypregna-4-ene-3 20-dione (RS) by Absidia coerulea AC307 was selected as a model system for evaluating the mechanism of β-cyclodextrin (β-CD) on the the steroid 11β-hydroxylation biotransformation process. It was found that the addition of cyclodextrin to RS and RSA biotransformation systems could effectively increase the speed of biotransformation and decrease the reactant's absorption by microorganism. There may be some relation between the two kinds affection induced by cyclodextrin, and the idea can be validated by Shewmon P G's theory. It showed that cyclodextrin can affect the steroid-permeating capability of the microorganism, and that seemed to be favourable for reactant entered into the microorganism.