100986-86-5Relevant articles and documents
Asymmetric metal-free synthesis of fluoroquinolones by organocatalytic hydrogenation
Rueping, Magnus,Stoeckel, Mirjam,Sugiono, Erli,Theissmann, Thomas
, p. 6565 - 6568 (2010)
A highly enantioselective organocatalytic transfer hydrogenation enabling the synthesis of both 6-fluoro-2-methyltetrahydroquinoline and 7,8-difluoro-3-methyl-benzoxazine has been developed. These key building blocks can for the first time be synthesized using the same methodology allowing fast and efficient, metal-free access to the antibiotic fluoroquinolones flumequine and levofloxacine.
Experimental and computational study on the enantioseparation of four chiral fluoroquinolones by capillary electrophoresis with sulfated-β-cyclodextrin as chiral selector
Ma, Qianyun,Cong, Wei,Liu, Ye,Geng, Zikai,Lin, Ying,Wang, Zhaokun
, p. 549 - 557 (2021/07/20)
In this work, enantioseparation of four chiral fluoroquinolones (FQs), namely, ofloxacin, gemifloxacin, lomefloxacin, and gatifloxacin, was achieved by capillary electrophoresis with sulfated-β-cyclodextrin (S-β-CD) as chiral selector. Factors affecting the enantiomeric resolution, such as the concentrations of S-β-CD, BGE pH conditions, and the buffer types and concentrations, were optimized and discussed. A BGE consisting of 30 g/L S-β-CD and 30-mM phosphate at pH?4.0 was found fit for enantiomeric resolution of ofloxacin and gemifloxacin, while the same BGE at pH?3.0 was suitable for enantioseparation of lomefloxacin and gatifloxacin. The pH-dependent experiments showed that separation resolutions of four FQs enantiomers were significantly affected by BGE pH, which was thought to be related with the varying electrostatic attraction between the enantiomers and chiral selector. To verify this speculation, molecular docking studies were used for further investigation of the enantiomeric recognition mechanism of S-β-CD. Molecular model indicated that hydrophobic effect and hydrogen bond were involved in host-guest inclusion, but the electrostatic attraction enhanced the chiral discrimination by increasing the difference in binding energy between individual enantiomers and S-β-CD. This work provided a further insight into the chiral recognition mechanisms of CD derivatives.
Structure-retention relationship for enantioseparation of selected fluoroquinolones
Hassan, Rasha M.,Yehia, Ali M.,Saleh, Ola A.,El-Azzouny, Aida A.,Aboul-Enein, Hassan Y.
, p. 828 - 836 (2018/04/10)
Fluoroquinolones are popular class of antibiotics with distinct chemical functionality. Most of them are ampholytes with one chiral center. Stereogeneic center is located either in the side ring of Gatifloxacin (GFLX) or in the quinolone core of Ofloxacin (OFLX). These two amphoteric fluoroquinolones have terminal amino groups in common. The unusual Nadifloxacin (NFLX) is an acidic fluoroquinolone with a core chiral center. Owing to chirality and functionality differences among GFLX, OFLX, and NFLX, we mapped these enantiomers onto structure-retention relationship. Amount of acetic acid modifier was studied in screened mobile phase and cellulose tris(3-chloro-4-methyl phenyl carbamate) (Lux cellulose-2) stationary phase. Experimental design of acetic acid% along with column temperature have been applied. Resolution and enantioselectivity have been related to structural features of the studied enantiomers. High amount of acid (0.4%) was optimum for the separation of either side chirality with a proximate amino group (GFLX) or core chirality without basic functionality (NFLX), while low amount (0.2%) is optimum for core chiral center with distal amino group (OFLX). Temperature has no significant effect on resolution and retention of enantiomers except for OFLX. Enantio-retention explains possible chiral selective and nonselective interactions. The proposed methods have been validated for pharmaceutical analyses.
