Studies On The Fermentation Scale-up Of Pregnenolone Transformed By Mucor Circinelloides Lusitanicus And The Biotransformation Of Andrographolide

1. Studies on the fermentation scale-up of pregnenolone transformed by Mucor circinelloides lusitanicus in the fermentor with a capacity of10litres. Mucor circinelloides lusitanicus, which was screened by our laboratory, can transform pregnenolone into7a-hydroxy pregnenolone (2) and7a,11α-dihydroxy pregnenolone(3). Product3could be the synthetic intermediate of eplerenone, which is aldosterone receptor antagonist. The single variable method was used to successive inspect the effect on the conversion yield from the five influence factors, including stirring speed, ventilation, the initial pH of culture medium, the optimal pH of conversion and substrate dosage. The final conclusion:stirring speed350rpm, ventilation is0.32m3·min-1, the initial pH of culture medium5.7, the optimal pH of conversion4.9, the optimal dosage of substrate2.0g·L-1. Under these conditions, the yield of product2can reach48.7%,which is increased nearly2.4percentage points than the prophase optimization of shaking flask fermentation process.2. The research on the microbial biotransformation of andrographolide, which has extensive pharmacological activity. We expect to find new derivatives of andrographolide through biotransformation methods which are difficult to be obtained by chemical method. The first stage was to screen strains with capacity to transform andrographolide from soil or to use the strains conserved in our laboratory. Then TLC methord was used to check the fermentation process. If new compound was founded, amplification experiments could be carried out. Using column chromatography to seprate the mixture, and using NMR、MS techniques to confirm the structure of products.Through the experiment, eight strains were selected, and the strain numbered AMT4can transform andrographolide completely with good product yield and higher selectivity.2Products were obtained, and the major product is confirrmed as dehydrated andrographis with the yield of36.4%.