Phytosterols can be transformed into pharmaceutical intermediates androst-4-ene-3,17-dione (4-AD) and androst-1,4-diene- 3,17-dione (Androst-1, 4-diene-3, 17-dione, ADD), AD (D) is an important intermediate for the synthesis of steroid drugs.
The low solubility of steroids is currently one of the main problems that limit their microbial conversion reaction rate and yield.
Surfactants can solubilize hydrophobic substances in aqueous solutions and increase their bioavailability in aqueous solutions. Below the critical micelle concentration, the solubilization effect of surfactants on hydrophobic substances is relatively small, while above the critical micelle concentration, the solubilization effect increases significantly. But because the surfactant itself is toxic to the bacteria,if the so high concentration will affect the normal metabolism of the bacteria.
The embedding effect of cyclodextrin can effectively improve the solubility of steroidal substrates, and the boots can increase the yield of output. Among the cyclodextrin products,Hydroxypropyl-β-cyclodextrin (HP-β-CD) is recommended.
Hydroxypropyl-β-cyclodextrin has been used as reaction media for the biodegradation of phytosterol side chains. HP-β-CD acts as a carrier for the combination of steroidal substrates and cells to improve the solubility of steroids in the reaction system of aqueous solutions, thereby increasing the biotransformation efficiency of microorganisms to steroidal substrates.