生技霉素小组分的研究 Ⅰ.分离纯化和4″-异丁酰螺旋霉素Ⅱ(生技霉素B_(2β))的结构鉴定

Chemical studies on minor components of shengjimycins I. Isolation and structure identification of 4"-O-isobutyrylspiramycin Ⅱ(shengjimycin B_(2β))

生技霉素是一组以4"-异成酰螺旋霉素为主的基因工程杂合抗生素，除了主要组分4"-异戊酚螺旋霉素Ⅲ、Ⅱ、Ⅰ（生技霉素A1、B1、E1）和小组分4"-了酰／异丁酞螺旋霉素Ⅲ（生技霉素A2a／A2β）以外，还含有其它4"-酸化螺旋霉素和少量杂质。采用连续逆流分配法，碱性硅胶柱层析，制备薄层层析和中压柱层析等分离方法，并以薄层层析和HPLC作为检测手段，从生技霉素混合物中分离得到了四个小组分A0、B2、B3和C2，其含量分别为0．5％、3．3％、6．2％和2．6％，其中B2为B2a和B2β两个异构体的混合物。经过UV、IR、SI－MS、GC－MS、1H－NMR、13C－NMR、1H－1H COSY等光谱分析，并与生技霉素 A1、B1、A2a、A2β等的光谱数据进行比较，确定了生技霉素B2a为4"-丁酰螺旋霉素Ⅱ，B2β为4"-异丁酰螺旋霉素Ⅱ，其中4"-异丁酰螺旋霉素Ⅱ为一个新的基因工程杂合抗生素。

ABSTRACT:Shengiimycins are a group of hybrid 4'-O-acylspiramycins which were produced by a genetically en-gineered strain WSJ-1 bearing 4'-O-isovaleryl-transferase gene. Besides the major components, 4'-O-isovalerylspiramy- cin Ⅲ,Ⅱ, Ⅰ(shengiimycin A1, B1, E1 ) and minor component 4'-O-butyryl/isobutyrylspiramycin Ⅲ(shengjimycinA2α/A2β), some other 4'-O-acylspiramycins and impurities have also been found in the mixture. By means ofcontinu- ous countercurrent distribution, basic silica gel column chromatography, preparative TLC and medium pressure liquidchromatography, monitored by TLC and HPLC, four minor components, shengjimycin A0, B2, B3 and C2 were isolatedfrom shengjimycin complex, the contents of them were 0. 5%, 3. 3%, 6. 2% and 2. 6%, respectively. Shengjimycin B2is a mixture of B2α. and B2β isomer. Based on careful analysis of UV, IR, SI-MS, GC-MS, 1H-NMR, 13 C-NMR,1 H-1H COSY, the structures of shengjimycin B2β. and B2β were elucidated as 4'-O-butyrylspiramycin Ⅱ and 4' -O-isobutyrylspiramycin Ⅱ, respectively. 4'-O-isobutyrylspiramycin Ⅱ(shengjimycin B2β) is a novel hybrid spiramycin an-tibiotic.