Study on Pseudomonas-selective beta-lactams containing siderophore stucture

1.荧光假单胞菌铁载体的分离建立了铁载体的分离方法。在低矿物质（Mg、Ca、Zn）条件下，发现有4种紫色铁载体（1-4）分泌。该结果表明，不同的矿物浓度可能产生不同类型的铁载体，为寻找新的铁载体研究提供了有价值的信息。荧光假单胞菌铁载体的结构分析经鉴定，主铁载体为红褐色的pyoverdim Pf 3/8/2（已知），棕色铁载体为pyoverdin Pf 1/1/1（已知）。新型紫色铁团（1-4）在pyoverdin pf3 /8/2中具有相同的肽段，但不同的发色团部分（5,6位饱和，R′=80（质量数）限定于此）。3,4有琥珀酰胺侧链，但谷氨酸为1,2.3。主要铁素（pyoverdin pf3/8/2）水解法制备发色团片段。以pyoverdin pf3/8/2.4的盐酸水解混合物制备反相高效液相色谱法获得纯发色团片段。6-氨基青霉素酸与pyoverdin pf3/8/2（或发色团部分）缀合物的合成。我们试图合成6-氨基青霉素酸与pyoverdin pf3/8/2（或发色团部分）的偶联物。然而，所需要的化合物不能得到。对共轭物合成技术的进一步研究正在进行中。

1.Isolation of Pseudomonas fluorescens siderophoresAn isolation method was developed for the siderophores. Four violet siderophores (1-4) were found to be secreted under low mineral (Mg, Ca, Zn) condition. This result indicated that different type siderophores might be produced depending upon mineral concentrations and provided the valuable information in the searching study for new siderophores.2.Structural analysis for Pseudomonas fluorescens siderophoresThe reddish-brown main siderophore was identified as pyoverdim Pf 3/8/2 (known), and the brown siderophore was as pyoverdin Pf 1/1/1 (known). Novel violet siderophores (1-4) have the same peptide moiety in pyoverdin Pf 3/8/2 and the different chromophore moiety (5,6 position was saturated, and R'=80 (mass number) was bounded to it). 3,4 have the side chain of succinic amide, but glutamic acid for 1,2.3.Preparation for the chromophore moiety by hydrolysis of main siderophore (pyoverdin Pf 3/8/2)The pure chromophore moiety was obtained by the preparative reversed-phase HPLC of the HCl-hydrolyzate mixture of pyoverdin Pf 3/8/2.4.Synthesis of the conjugate of 6-aminopenicillanic acid with pyoverdin Pf 3/8/2 (or the chromophore moiety).We attempted to synthesize the conjugate of 6-aminopenicillanic acid with pyoverdin Pf 3/8/2 (or the chromophore moiety). However, the desired compound could be not obtained. Further study of the techniques to synthesizing the conjugates is now under way.