Study On Dispersion Of Epoxy Progesterone In Water And Bioconversion By Rhizopus Nigricans

Epoxyprogesterone was a kind of important intermediates,the hydroxylation and derivatives of epoxyprogesterone has a variety of biological activity;which was an important drug and drug precursor.Hydroxyls of C11 has attracted more and more attention,because it plays an indispensable role in drug efficacy.At present,The main problem of domestic steroidal pharmaceutical intermediates manufacturers was:the microbial bioconversion rate is relatively low under a higher feed concentration,which was increasing the cost of production.In this study,preparation of epoxyprogesterone solid lipid nanoparticles,epoxyprogesterone-β-cyclodextrin complex substrate to improve the solubility in water,make its dispersed particle decrescent,contact endoenzyme easily;thus to improve Rhizopus nigricans C11α-hydroxylation bioconversion rate and improve the economic benefits.Study on effect of epoxyprogesterone solid lipid nanoparticles on the substrate solubility in water.Through the single-factor test,the optimize conditions of preparation of epoxy progestin solid lipid nanoparticle was:the ratio of lecithin to monostearin with 5:1,the organic phase system of ethyl acetate,Water phase system of 1%80-twain solution,the ratio of organic/water volume with 3:1,adding time from organic phase to water of 5 min,emulsion of 50 ℃,emulsification suspension speed of 90 rpm,emulsification time of 2 h,ultrasonic time of 7 min,rotation temperature of 55 ℃,vacuum degree of 0.08 MPa,rotation speed for 80 rpm,carried medicine amount of 20:1.Epoxyprogestin solid lipid nanoparticle particle size of 199.8 nm,polydispersity index(PDI)of 0.175.When the concentration of epoxyprogesterone>0.5%in water,nanoparticle particle size increased rapidly and the nanoparticle precipitated easily.The feed concentration is far from using in industry.And the drug loading is low,the costs was high for producing.Therefore,it was obviously impractical to improve the steroid drug intermediates solubility in the water by preparation of epoxy progestin solid lipid nanoparticle at large-scale industrial application.Study on effect of epoxyprogesterone-β-cyclodextrin complex on the substrate solubility in water.Plackett-Burman surfaces optimum conditions were optimized as follows:stirring temperature of 50.19 ℃,organic phase epoxy progesterone concentration of 3.22%,and the actual measured encapsulation efficiency was 98.63%.Epoxy progesterone-β-cyclodextrin complex with different encapsulation ratio were obtained under this condition,the actual measured size was about 2 μm,its water solubility was 21.9 mg/L,and it improved 7 times water solubility relative to the epoxy progesterone substrate.The hydroxylation of epoxyprogesterone by Rhizopus nigricans was studied by adding epoxy progesterone-β-cyclodextrin complex substrate to the fermentation.The best conversion conditions were:encapsulation ratio of 1:1,feeding density of 1.5%,glucose content of 3.15%(g/mL),loading volume of 100/500 mL,inoculation amount of 107 mL-1,initial pH of medium 4.2,cultivate temperature of 26 ℃,rotate-speed of 180 rpm and feeding time:half of the substrate adding into medium directly,another substrate adding into medium after inoculation training 27 h.The highest bioconversion rate was 20.16%.