Department of Chemistry, Faculty of Science, Taibah University, Al-MAdinah Al-Munawarah, P.O. Box 30002, Kingdom of Saudi Arabia.
J Fluoresc. 2013 Jan;23(1):93-101. doi: 10.1007/s10895-012-1120-7. Epub 2012 Sep 20.
The photophysicochemical properties of selected fluoroquinolones in different solvents of various physical properties, including polarity and hydrogen bonding ability, were investigated using steady state fluorescence spectroscopy. The solvent-dependant fluorescence emission spectra of selected fluoroquinolones, namely ciprofloxacin (CIPR) and enrofloxacin (ENRO), were employed to gain insights concerning its photophysicochemical properties of interests. Interestingly, fluorescence spectra of the selected drugs exhibited structured emission spectra in nonpolar solvents such as hexane, whereas unstructured spectra were observed in more polar solvents such as alcohols and water. Also, a notable bathochromic shift in λ(max)(em) was observed in fluorescence spectra of both drugs with increasing solvent polarity that resulted in biphasic behavior upon applying the Lippert-Mataga correlation that correspond to general and specific solvent effects. Applying the Lippert-Mataga correlation to the fluorescence spectra of CIPR and ENRO in various solvents was employed to estimate the dipole moment difference between the ground and excited states of them, Δμ(μ(e) - μ(g)), where obtained results revealed the values of 9.4 and 16.2 Debye for the LE and ICT states of ENRO, respectively, and 8.0 and 16.2 Debye for the LE and ICT states of CIPR, respectively. Multiple linear regression analysis (MLRA) based on Kamlet-Taft equating was applied against absorption frequency (ν(abs)), emission frequency (ν(em)), Stokes shift (∆ν), and fluorescence quantum yield (Φ(f)), where obtained results revealed excellent correlation (R: 0.916-0.966) that are consistent with other results considering the effect of solvent polarizability, hydrogen bonding ability, and viscosity on the photophysicochemical properties of the studied fluoroquinolones.
采用稳态荧光光谱法研究了不同物理性质（包括极性和氢键能力）的各种溶剂中选定氟喹诺酮类药物的光物理化学性质。选择的氟喹诺酮类药物（环丙沙星（CIPR）和恩诺沙星（ENRO））的溶剂依赖性荧光发射光谱用于深入了解其感兴趣的光物理化学性质。有趣的是，所选药物的荧光光谱在非极性溶剂（如己烷）中显示出结构化的发射光谱，而在极性较大的溶剂（如醇和水）中则观察到非结构化的光谱。此外，随着溶剂极性的增加，两种药物的荧光光谱均观察到 λ（max）（em）的显著红移，这导致在应用 Lippert-Mataga 相关时表现出双相行为，这对应于一般和特定溶剂效应。在各种溶剂中，将 Lippert-Mataga 相关应用于 CIPR 和 ENRO 的荧光光谱，以估计它们的基态和激发态之间的偶极矩差Δμ（μ（e）-μ（g）），结果表明 ENRO 的 LE 和 ICT 态的分别为 9.4 和 16.2 德拜，而 CIPR 的 LE 和 ICT 态的分别为 8.0 和 16.2 德拜。基于 Kamlet-Taft 等效物的多元线性回归分析（MLRA）应用于吸收频率（ν（abs）），发射频率（ν（em）），斯托克斯位移（∆ν）和荧光量子产率（Φ（f）），结果表明相关性非常好（R：0.916-0.966），与其他考虑溶剂极化率，氢键能力和粘度对研究的氟喹诺酮类药物光物理化学性质的影响的结果一致。
