Synthesis, Physicochemical Characterization using a Facile Validated HPLC Quantitation Analysis Method of 4-Chloro-phenylcarbamoyl-methyl Ciprofloxacin and Its Biological Investigations.

A novel derivative of ciprofloxacin (Cpx) was synthesized and characterized using various analytical techniques, including FT-IR spectroscopy, UV-Vis spectroscopy, TEM and SEM analysis, 1H NMR, 13C NMR, and HPLC analysis. The newly prepared Cpx derivative (Cpx-Drv) exhibited significantly enhanced antibacterial properties compared to Cpx itself. In particular, Cpx-Drv demonstrated a 51% increase in antibacterial activity against S. aureus and a 30% improvement against B. subtilis. It displayed potent inhibitory effects on topoisomerases II (DNA gyrase and topoisomerase IV) as potential molecular targets, with IC50 values of 6.754 and 1.913 µg/mL, respectively, in contrast to Cpx, which had IC50 values of 2.125 and 0.821 µg/mL, respectively. Docking studies further supported these findings, showing that Cpx-Drv exhibited stronger binding interactions with the gyrase enzyme (PDB ID: 2XCT) compared to the parent Cpx, with binding affinities of -10.3349 and -7.7506 kcal/mole, respectively.

Ciprofloxacin Derivative-Loaded Nanoparticles Synergize with Paclitaxel Against Type II Human Endometrial Cancer.

Combinations of chemotherapeutic agents comprise a clinically feasible approach to combat cancers that possess resistance to treatment. Type II endometrial cancer is typically associated with poor outcomes and the emergence of chemoresistance. To overcome this challenge, a combination therapy is developed comprising a novel ciprofloxacin derivative-loaded PEGylated polymeric nanoparticles (CIP2b-NPs) and paclitaxel (PTX) against human type-II endometrial cancer (Hec50co with loss of function p53). Cytotoxicity studies reveal strong synergy between CIP2b and PTX against Hec50co, and this is associated with a significant reduction in the IC50 of PTX and increased G2/M arrest. Upon formulation of CIP2b into PEGylated polymeric nanoparticles, tumor accumulation of CIP2b is significantly improved compared to its soluble counterpart; thus, enhancing the overall antitumor activity of CIP2b when co-administered with PTX. In addition, the co-delivery of CIP2b-NPs with paclitaxel results in a significant reduction in tumor progression. Histological examination of vital organs and blood chemistry was normal, confirming the absence of any apparent off-target toxicity. Thus, in a mouse model of human endometrial cancer, the combination of CIP2b-NPs and PTX exhibits superior therapeutic activity in targeting human type-II endometrial cancer.

Synthesis and molecular docking of new N4-piperazinyl ciprofloxacin hybrids as antimicrobial DNA gyrase inhibitors.

A series of N-4 piperazinyl ciprofloxacin derivatives as urea-tethered ciprofloxacin-chalcone hybrids 2a-j and thioacetyl-linked ciprofloxacin-pyrimidine hybrids 5a-i were synthesized. The target compounds were investigated for their antibacterial activity against S. aureus, P. aeruginosa, E. coli, and C. albicans strains, respectively. Ciprofloxacin derivatives 2a-j and 5a-i revealed broad antibacterial activity against either Gram positive or Gram negative strains, with MIC range of 0.06-42.23 µg/mL compared to ciprofloxacin with an MIC range of 0.15-3.25 µg/mL. Among the tested compounds, hybrids 2b, 2c, 5a, 5b, 5h, and 5i exhibited remarkable antibacterial activity with MIC range of 0.06-1.53 µg/mL against the tested bacterial strains. On the other hand, compounds 2c, 2e, 5c, and 5e showed comparable antifungal activity to ketoconazole against candida albicans with MIC range of 2.03-3.89 µg/mL and 2.6 µg/mL, respectively. Further investigations showed that some ciprofloxacin hybrids have inhibitory activity against DNA gyrase as potential molecular target compared to ciprofloxacin with IC50 range of 0.231 ± 0.01-7.592 ± 0.40 µM and 0.323 ± 0.02 µM, respectively. Docking studies of compounds 2b, 2c, 5b, 5c, 5e, 5h, and 5i on the active site of DNA gyrase (PDB: 2XCT) confirmed their ability to form stable complex with the target enzyme like that of ciprofloxacin.

New 1,2,3-triazole linked ciprofloxacin-chalcones induce DNA damage by inhibiting human topoisomerase I& II and tubulin polymerization.

A series of novel 1,2,3-triazole-linked ciprofloxacin-chalcones 4a-j were synthesised as potential anticancer agents. Hybrids 4a-j exhibited remarkable anti-proliferative activity against colon cancer cells. Compounds 4a-j displayed IC50s ranged from 2.53-8.67 µM, 8.67-62.47 µM, and 4.19-24.37 µM for HCT116, HT29, and Caco-2 cells; respectively, whereas the doxorubicin, showed IC50 values of 1.22, 0.88, and 4.15 µM. Compounds 4a, 4b, 4e, 4i, and 4j were the most potent against HCT116 with IC50 values of 3.57, 4.81, 4.32, 4.87, and 2.53 µM, respectively, compared to doxorubicin (IC50 = 1.22 µM). Also, hybrids 4a, 4b, 4e, 4i, and 4j exhibited remarkable inhibitory activities against topoisomerase I, II, and tubulin polymerisation. They increased the protein expression level of γH2AX, indicating DNA damage, and arrested HCT116 in G2/M phase, possibly through the ATR/CHK1/Cdc25C pathway. Thus, the novel ciprofloxacin hybrids could be exploited as potential leads for further investigation as novel anticancer medicines to fight colorectal carcinoma.

Novel urea linked ciprofloxacin-chalcone hybrids having antiproliferative topoisomerases I/II inhibitory activities and caspases-mediated apoptosis.

A novel series of urea-linked ciprofloxacin (CP)-chalcone hybrids 3a-j were synthesized and screened by NCI-60 cancer cell lines as potential cytotoxic agents. Interestingly, compounds 3c and 3j showed remarkable antiproliferative activities against both colon HCT-116 and leukemia SR cancer cells compared to camptothecin, topotecan and staurosporine with IC50 = 2.53, 2.01, 17.36, 12.23 and 3.1 µM for HCT-116 cells, respectively and IC50 = 0.73, 0.64, 3.32, 13.72 and 1.17 µM for leukemia SR cells, respectively. Also, compounds 3c and 3j exhibited inhibitory activities against Topoisomerase (Topo) I with % inhibition = 51.19% and 56.72%, respectively, compared to camptothecin (% inhibition = 60.05%) and Topo IIß with % inhibition = 60.81% and 60.06%, respectively, compared to topotecan (% inhibition = 71.09%). Furthermore, compound 3j arrested the cell cycle of leukemia SR cells at G2/M phase. It induced apoptosis both intrinsically and extrinsically via activation of proteolytic caspases cascade (caspases-3, -8, and -9), release of cytochrome C from mitochondria, upregulation of proapoptotic Bax and down-regulation of Bcl-2 protein level. Thus, the new ciprofloxacin derivative 3j could be considered as a potential lead for further optimization of antitumor agent against leukemia and colorectal carcinoma.

Design, synthesis and molecular docking of new N-4-piperazinyl ciprofloxacin-triazole hybrids with potential antimicrobial activity.

New N-4-piperazinyl ciprofloxacin-triazole hybrids 6a-o were prepared and characterized. The in vitro antimycobacterial activity revealed that compound 6a experienced promising antimycobacterial activity against Mycobactrium smegmatis compared with the reference isoniazide (INH). Additionally, compound 6a exhibited broad spectrum antibacterial activity against all the tested strains either Gram-positive or Gram-negative bacteria compared with the reference ciprofloxacin. Also, compounds 6g and 6i displayed considerable antifungal activity compared with the reference ketoconazole. DNA cleavage assay of the highly active compounds 6c and 6h showed a good correlation between the Mycobactrium cleaved DNA gyrase assay and their in vitro antimycobactrial activity. Moreover, molecular modeling studies were done for the designed ciprofloxacin derivatives to predict their binding modes towards Topoisomerase II enzyme (PDB: 5bs8).

Current Trends and Future Directions of Fluoroquinolones.

Fluoroquinolones represent an interesting synthetic class of antimicrobial agents with broad spectrum and potent activity. Since the discovery of nalidixic acid, the prototype of quinolones, several structural modifications to the quinolone nucleus have been carried out for improvement of potency, spectrum of activity, and to understand their structure activity relationship (SAR). The C-7 substituent was reported to have a major impact on the activity. Accordingly, Substitution at C-7 or its N-4-piperazinyl moiety was found to affect potency, bioavailability, and physicochemical properties. Also, it can increase the affinity towards mammalian topoisomerases that may shift quinolones from antibacterial to anticancer candidates. Moreover, the presence of DNA topoisomerases in both eukaryotic and prokaryotic cells makes them excellent targets for chemotherapeutic intervention in antibacterial and anticancer therapies. Based on this concept, several fluoroquionolones derivatives have been synthesized and biologically evaluated as antibacterial, antituberculosis, antiproliferative, antiviral and antifungal agents. This review is an attempt to focus on the therapeutic prospects of fluoroquinolones with an updated account on their atypical applications such as antitubercular and anticancer activities.

New antiproliferative 7-(4-(N-substituted carbamoylmethyl)piperazin-1-yl) derivatives of ciprofloxacin induce cell cycle arrest at G2/M phase.

New N-4-piperazinyl derivatives of ciprofloxacin 2a-g were prepared and tested for their cytotoxic activity. The primary in vitro one dose anticancer assay experienced promising cytotoxic activity against different cancer cell lines especially non-small cell lung cancer. Independently, compounds 2b, 2d, 2f and 2g showed anticancer activity against human non-small cell lung cancer A549 cells (IC50=14.8, 24.8, 23.6 and 20.7µM, respectively) compared to the parent ciprofloxacin (IC50 >100µM) and doxorubicin as a positive control (IC50=1µM). The flow cytometric analysis for 2b showed dose dependent G2/M arrest in A549 cells. Also, 2b increased the expression of p53 and p21 and decreased the expression of cyclin B1 and Cdc2 proteins in A549 cells without any effect on the same proteins expression in WI-38 cells. Specific inhibition of p53 by pifithrin-α reversed the G2/M phase arrest induced by the 2b compound, suggesting contribution of p53 to increase. Taken together, 2b induced G2/M phase arrest via p53/p21 dependent pathway. The results indicate that 2b can be used as a lead compound for further development of new derivatives against non-small cell lung cancer.