CAJ | 학술논문

　　左氧氟羧酸是合成喹诺酮类抗菌药物左氧氟沙星的主要原料,在其合成过程中产生了一个微量未知杂质。运用高效液相色谱/质谱联用结合串联质谱技术对其进行分析发现,该杂质的分子量及分子式与左氧氟羧酸的相同,其碰撞诱导解离二级和三级质谱产生的碎片离子及其丰度也与左氧氟羧酸的相似。通过对该杂质的多级质谱裂解机理进行分析总结,结合高分辨质谱数据,推测该杂质为9,10-二氟-11-羟基-2-甲基-2,3-二氢-1,6-苯并[e][1,4]噁唑啉-5,7-二酮,与左氧氟羧酸分子结构的差异体现为异丙基环合位置不同。其结构得到核磁共振波谱技术的进一步确证。
　　좌양불최산시합성규낙동류항균약물좌양불사성적주요원료,재기합성과정중산생료일개미량미지잡질。운용고효액상색보/질보련용결합천련질보기술대기진행분석발현,해잡질적분자량급분자식여좌양불최산적상동,기팽당유도해리이급화삼급질보산생적쇄편리자급기봉도야여좌양불최산적상사。통과대해잡질적다급질보렬해궤리진행분석총결,결합고분변질보수거,추측해잡질위9,10-이불-11-간기-2-갑기-2,3-이경-1,6-분병[e][1,4]오서람-5,7-이동,여좌양불최산분자결구적차이체현위이병기배합위치불동。기결구득도핵자공진파보기술적진일보학증。
An unknown impurity in the bulk drug levofloxacin carboxylic acid was detected by high perfor-mance liquid chromatography coupled with mass spectrometry (HPLC-MS). The impurity has the same formula and molecular weight with levofloxacin carboxylic acid. The mass multi-stage spectrometric spectra (MSn) of impurity exhibit characteristic fragmentation routes similar to those of levofloxacin carboxylic acid. The un-known product was then proposed as 9, 10-difluoro-11-hydroxy-2-methyl-2, 3-dihydro-1, 6-(metheno)benzo[e][1, 4]oxazonine-5, 7-dione on the basis of the proposed mass spectrometric mechanism and exact mass evidences. The proposed structures were further confirmed by NMR experiments.