Marine natural products offer a promising source in the development of new antibiotic drugs.Two previously undescribed compounds,including one sulfur-bearing alkaloid named quinosumycin(1)along with one chromone deriv...Marine natural products offer a promising source in the development of new antibiotic drugs.Two previously undescribed compounds,including one sulfur-bearing alkaloid named quinosumycin(1)along with one chromone derivative namely chromycone(2),were discovered from an ethyl acetate(EtOAc)extract of marine Streptomyces diastaticus NBU2966 through a bioactivity-guided isolation prioritized for antimicrobial potential.The analysis of nuclear magnetic resonance(NMR)spectroscopy,high resolution electrospray ionization mass spectroscopy(HRESIMS)data,and electronic circular dichroism(ECD)calculations enabled the elucidation of their structures and the determination of their absolute configurations.Quinosumycin(1)is the first heterodimer scaffold incorporating quinolinone and quinazolinone motifs coupled by a thioether bond.Interestingly,Compound 1 exhibited a relatively selective growth inhibition against methicillin-resistant Staphylococcus aureus(MRSA)with the minimal inhibitory concentration(MIC)value of 8μg/mL.展开更多
[Objective] The research aimed to screen Streptomyces hygroscopicus strains with high production of agricultural antibiotics. [ Method] A strain of S. hygroscopicus was screened from the soil of Hainan Island. After n...[Objective] The research aimed to screen Streptomyces hygroscopicus strains with high production of agricultural antibiotics. [ Method] A strain of S. hygroscopicus was screened from the soil of Hainan Island. After natural screening and consecutive ultraviolet induced mutation twice, S6-7 strain was obtained as the original strain then treated by UV irradiation and streptomycin resistance screening, and finally rescreened through shake-flask fermentation. [Result] 7 better strains were selected by primary screening from 62 single colonies which were picked out randomly. After 3 generations of consecutive cultivation on slant media and rescreening, 5 strains presented obvious forward mutation. The forward mutation rate reached 8.06%, and the largest production increasing rate came up to 25.11%. [Conclusion] By combining streptomycin resistance screening and conventional ultraviolet induced mutation, both the antibiotic-producing capacity and forward mutation screening efficiency of the original strain were greatly enhanced.展开更多
基金Supported by the National Natural Science Foundation of China(No.42176101)the Ningbo Youth Science and Technology Innovation Leading Project(No.2024QL063)+2 种基金the National 111 Project of China(No.D16013)the Scientific Research Fund of Zhejiang Provincial Education Department(No.Y202250186)the Li Dak Sum Yip Yio Chin Kenneth Li Marine Biopharmaceutical Development Fund。
文摘Marine natural products offer a promising source in the development of new antibiotic drugs.Two previously undescribed compounds,including one sulfur-bearing alkaloid named quinosumycin(1)along with one chromone derivative namely chromycone(2),were discovered from an ethyl acetate(EtOAc)extract of marine Streptomyces diastaticus NBU2966 through a bioactivity-guided isolation prioritized for antimicrobial potential.The analysis of nuclear magnetic resonance(NMR)spectroscopy,high resolution electrospray ionization mass spectroscopy(HRESIMS)data,and electronic circular dichroism(ECD)calculations enabled the elucidation of their structures and the determination of their absolute configurations.Quinosumycin(1)is the first heterodimer scaffold incorporating quinolinone and quinazolinone motifs coupled by a thioether bond.Interestingly,Compound 1 exhibited a relatively selective growth inhibition against methicillin-resistant Staphylococcus aureus(MRSA)with the minimal inhibitory concentration(MIC)value of 8μg/mL.
基金Supported by Basic Research Fund for Central Nonprofit Institutes(Agro-environmental Protection Institute of Ministry of Agriculture)~~
文摘[Objective] The research aimed to screen Streptomyces hygroscopicus strains with high production of agricultural antibiotics. [ Method] A strain of S. hygroscopicus was screened from the soil of Hainan Island. After natural screening and consecutive ultraviolet induced mutation twice, S6-7 strain was obtained as the original strain then treated by UV irradiation and streptomycin resistance screening, and finally rescreened through shake-flask fermentation. [Result] 7 better strains were selected by primary screening from 62 single colonies which were picked out randomly. After 3 generations of consecutive cultivation on slant media and rescreening, 5 strains presented obvious forward mutation. The forward mutation rate reached 8.06%, and the largest production increasing rate came up to 25.11%. [Conclusion] By combining streptomycin resistance screening and conventional ultraviolet induced mutation, both the antibiotic-producing capacity and forward mutation screening efficiency of the original strain were greatly enhanced.
