两种氟喹诺酮类抗生素在酸碱中的光谱特性

Spectrum Characteristic of Typical Fluoroquinolone Antibiotics Under Different Acid-basic Conditions

摘要:

氟喹诺酮类药物的结构形态光谱性质受酸碱度的影响非常显著.在强酸介质(pH<3)中，氟喹诺酮为强阳离子，荧光和紫外强度较弱；当pH为3~4时，氟喹诺酮为两性离子形式，荧光强度和紫外强度最大，环丙沙星（CIP）的最大激发波长和最大发射波长分别为280和459 mm，诺氟沙星(NOR)为281和450 mm；当pH为中性时，氟喹诺酮为弱阴离子，光谱蓝移，同时强度降低；在碱性条件下，氟喹诺酮为阴离子，荧光和紫外强度随着pH的升高而降低,但光谱形状基本不变.

Abstract:

The structural morphology and spectra characteristic of Ciprofloxacin (CIP) and Norfloxacin (NOR) was strongly affected by the pH.In strong acidic solutions,fluoroquinolone molecules exist as strong cation to achieve a weaker intensity.When the pH value increases to 3~4,fluoroquinolone molecule exist as zwitterions,which is the strongest fluorescence form to have maximum intensity;the maximum exciting-emission wavelength (λexλem)of CIP and NOR were 280＼459 nm and 281＼450 nm,respectively.Along with the increase in neutral pH value,fluoroquinolone molecules exist as weak anion,fluorescence spectrum and UV spectrum change,the intensity decreases;under basic condition,fluoroquinolone molecule exists in anion ion form,and fluorescence and UV intensity decreases with pH increasing,but spectrum remains essentially constant.