Study On Screening Of A Bacterial Strain Degradable Of Quinestrol And The Activity Of Degradation Products

Quinestrol,is a long-acting synthetic estrogen,a derivative of ethinylestradiol.Its estrogenic activity is about 4 times than its matrix,and it has strong antifertility effects.Quinestrol is stored in body fat and subsequently released slowly and converted into 17a-ethinylestradiol.It was used in contraceptive and hormone replacement therapy and occasionally for treating breast cancer and prostate cancer.Quinestrol,as one of the important Endocrine-disrupting compounds,can not only cause feminize the male organisms,but also can cause harm to humans.The goal of this work is screening a microbe which can biodegrade quinestrol.The main results are as follows:（1）19 strains of microbes were isolated from soil collected from a pharmaceutical factory in Xianju,Zhejiang,and 3 strains of microbes were isolated from the bohai China sea,with other 14 microorganisms kept in our lab,were used to biodegrade quinestrol.Two active strains were found having the activity of biological degradation.By morphology,16S rDNA sequence analysis and phylogenetic analysis,these two microbes were determined as:Amycolatopsis sp.WP1,Sphingopyxis sp.syy-1.This is the first research of biodegradation of quinestrol.（2）We studied the influences of initial concentration of substrate and the degradation time on the degradation of quinestrol by Amycolatopsis sp.WP1.The research found that the degradation rate was decreased when the initial concentration of substrate was increased.In the liquid medium with quinestrol concentration was 100 mg/L,after 10 days reaction,degradation rate reached to 89.5%;when the initial concentration was 50 mg/L,after 5 days reaction,the degradation rate reached to 100%.The fermented liquid was extracted and separated,four degradation products were purified.compound 3 was identified as2-hydroxy-6-methoxy-quinestrol,it may be a new compound.Compound4 was identified as 2-hydroxy-6-keto-9（11）ene-quinestrol,it’s also a new compound.Compound 1 and 2 was speculated as a glycosylation of quinestrol.We studied the anti-cancer by CHO-K1 with the 4 degradation products.The biological activity showed that compound 2 and 4 were of certain anti-cancer activity against CHO-K1 with IC₅₀0 of 23.91±2.61μg/mL,30.95±0.61μg/mL,respectively.The anti-cancer effect of these two compounds,just as 5-Fluorouracil,were better than quinestrol.Compound 3 and 4 was evaluated for the first time for its anti-cancer against the CHO-K1 cancer cell lines.（3）We studied the influences of medium,inoculum,initial concentration of substrate and the degradation time on the degradation of quinestrol by Sphingopyxis sp.syy-1.The results showed that when using a nutrient agar medium and 10%inoculation amount,we got the optimum degradation rate.In the liquid medium with quinestrol concentration was 50 mg/L,after 10 days reaction,degradation rate reached to 70%.This is the first time to study on degradation of quinestrol by Sphingopyxis sp.syy-1.