Pharmacological Characterization of 7-(4-(Piperazin-1-yl)) Ciprofloxacin Derivatives: Antibacterial Activity, Cellular Accumulation, Susceptibility to Efflux Transporters, and Intracellular Activity

Perceived benefit of antibiotics irrigation before pharyngeal repair of severe cut-throat injuries

INTRODUCTION

Wound irrigation has been employed as an important surgical step to remove bacteria, devitalized tissues, and foreign bodies from surgical sites to prevent infection and confer to the wound maximum potential of healing.

METHOD

A prospective study was conducted at Federal Medical Centre, Gusau, between January 2019- August 2023 to assess the benefit of antibiotics as additives in irrigation of dirty wounds. Seven (7) patients in total were presented with severe cut-throat injuries that require laryngopharyngoplasty. A combination of injection ciprofloxacin and metronidazole were used as additives into 1 L of normal saline, low pressure irrigation was done using 20mls syringe fitted to a broken needle or canular. Dysphagia Outcome and Severity Scale (DOSS) was used to assess return of pharyngeal function.

RESULT

The mean time of presentation of the patients was 34 ± 29 h (µ ± standard deviation) and a range of 6-72 h. The mean repair time was 58.3 ± 38.4 h with a range of 24-120 h. Most of the patients (85.7 %) had dysphagia outcome and severity scale of level 5 when per oral feeding was started with steady progress until discharge day.

CONCLUSION

Wound irrigation is one of the most crucial steps in treating severe cut-throat injuries. Based on our experience, adding antibiotics to the irrigant has shown potential in the control of local infection, particularly where patients present late.

Synthesis of ciprofloxacin-linked 1,2,3-triazole conjugates as potent antibacterial agents using click chemistry: exploring their function as DNA gyrase inhibitors via in silico- and in vitro-based studies

The antibacterial efficacy of some newly developed C-3 carboxylic group-containing ciprofloxacin-linked 1,2,3-triazole conjugates was studied. Twenty-one compounds from three different series of triazoles were synthesized using click chemistry and evaluated for their antibacterial activity against nine different pathogenic strains, including three Gram-positive strains, i.e. Enterococcus faecalis (ATCC29212), Staphylococcus aureus (ATCC25923), Staphylococcus epidermidis (clinical isolate), and six Gram-negative bacterial strains, i.e. Escherichia coli (ATCC25922), Pseudomonas aeruginosa (ATCC27853), Salmonella typhi (clinical isolate), Proteus mirabilis (clinical isolate), Acinetobacter baumannii (clinical isolate) and Klebsiella pneumonia (clinical isolate). Among the compounds, 10, 10a, 10b, 10c, 10d, 11a, 11f, 12c, 12e and 12f showed excellent activity with MIC values upto 12.5 μg mL-1, whereas the control ciprofloxacin showed MIC values of 0.781-25 μg mL-1 towards various strains. In addition, the low toxicity profile of the synthesized molecules revealed that they are potent antibiotics. Molecular docking and MD analysis were performed using the protein structure of E. coli DNA gyrase B, which was further corroborated with an in vitro assay to evaluate the inhibition of DNA gyrase. The analysis revealed that compound 10b was the most potent inhibitor of DNA gyrase compared to ciprofloxacin, which was employed as the positive control. Furthermore, the structure of two title compounds (11a and 12d) was characterized using single-crystal analysis.

N-Acylated Ciprofloxacin Derivatives: Synthesis and In Vitro Biological Evaluation as Antibacterial and Anticancer Agents

A novel series of N-acylated ciprofloxacin (CP) conjugates 1-21 were synthesized and screened as potential antimicrobial agents. Conjugates 1 and 2 were 1.25-10-fold more potent than CP toward all Staphylococci (minimal inhibitory concentration 0.05-0.4 μg/mL). Most of the chloro- (3-7), bromo- (8-11), and CF₃-alkanoyl (14-16) derivatives expressed higher or comparable activity to CP against selected Gram-positive strains. A few CP analogues (5, 10, and 11) were also more effective toward the chosen clinical Gram-negative rods. Conjugates 5, 10, and 11 considerably influenced the phases of the bacterial growth cycle over 18 h. Additionally, compounds 2, 4-7, 9-12, and 21 exerted stronger tuberculostatic action against three Mycobacterium tuberculosis isolates than the first-line antitubercular drugs. Amides 1, 2, 5, 6, 10, and 11 targeted gyrase and topoisomerase IV at 2.7-10.0 μg/mL, which suggests a mechanism of antibacterial action related to CP. These findings were confirmed by molecular docking studies. In addition, compounds 3 and 15 showed high antiproliferative activities against prostate PC3 cells (IC₅₀ 2.02-4.8 μM), up to 6.5-2.75 stronger than cisplatin. They almost completely reduced the growth and proliferation rates in these cells, without a cytotoxic action against normal HaCaT cell lines. Furthermore, derivatives 3 and 21 induced apoptosis/necrosis in PC3 cells, probably by increasing the intracellular ROS amount, as well as they diminished the IL-6 level in tumor cells.

Design, synthesis, and biological investigation of quinoline/ciprofloxacin hybrids as antimicrobial and anti-proliferative agents

Ciprofloxacin-Piperazine C-7 linked quinoline derivatives 6a–c and 8a–c were synthesized and investigated for their antibacterial, antifungal, and anti-proliferative activities. Ciprofloxacin-quinoline-4-yl-1,3,4 oxadiazoles 6a and 6b showed promising anticancer activity against SR- leukemia and UO-31 renal cancer cell lines. The hybrids 8a–c and compound 6b exhibited noticeable antifungal activities against C.Albicans; 8a experienced the most potent antifungal activity compared to Itraconazole with MICs of 21.88 µg/mL and 11.22 µg/mL; respectively. Most of derivatives displayed better antibacterial activity than the parent ciprofloxacin against all the tested strains. Compound 6b was the most potent against the highly resistant Gram-negative K.pneumoniae with MIC 16.96 of µg/mL relative to the parent ciprofloxacin (MIC = 29.51 µg/mL). Docking studies of the tested hydrides in the active site of Topo IV enzyme of K.pneumoniae (5EIX) and S.aureus gyrase (2XCT) indicate that they had stronger binding affinity in both enzymes than ciprofloxacin but have different binding interactions. The hybrid 6b could be considered a promising lead compound for finding new dual antibacterial/anticancer agents. Moreover, Compound 8a could be a lead for discovering new dual antibacterial/antifungal agents.

Graphical abstract

Fluoroquinolones' Biological Activities against Laboratory Microbes and Cancer Cell Lines

Development of novel derivatives to rein in and fight bacteria have never been more demanding, as microbial resistance strains are alarmingly increasing. A multitude of new fluoroquinolones derivatives with an improved spectrum of activity and/or enhanced pharmacokinetics parameters have been widely explored. Reporting novel antimicrobial agents entails comparing their potential activity to their parent drugs; hence, parent fluoroquinolones have been used in research as positive controls. Given that these fluoroquinolones possess variable activities according to their generation, it is necessary to include parent compounds and market available antibiotics of the same class when investigating antimicrobial activity. Herein, we provide a detailed guide on the in vitro biological activity of fluoroquinolones based on experimental results published in the last years. This work permits researchers to compare and analyze potential fluoroquinolones as positive control agents and to evaluate changes occurring in their activities. More importantly, the selection of fluoroquinolones as positive controls by medicinal chemists when investigating novel FQs analogs must be correlated to the laboratory pathogen inquest for reliable results.

Antimicrobial Resistance in Listeria Species

For nearly a century the use of antibiotics to treat infectious diseases has benefited human and animal health. In recent years there has been an increase in the emergence of antibiotic-resistant bacteria, in part attributed to the overuse of compounds in clinical and farming settings. The genus Listeria currently comprises 17 recognized species found throughout the environment. Listeria monocytogenes is the etiological agent of listeriosis in humans and many vertebrate species, including birds, whereas Listeria ivanovii causes infections mainly in ruminants. L. monocytogenes is the third-most-common cause of death from food poisoning in humans, and infection occurs in at-risk groups, including pregnant women, newborns, the elderly, and immunocompromised individuals.

Biotransformation of ciprofloxacin by Xylaria longipes: structure elucidation and residual antibacterial activity of metabolites

The impressive ability of the fungus Xylaria longipes to transform the highly persistent fluoroquinolone ciprofloxacin into microbiologically less active degradation products was demonstrated. Fluoroquinolones are used extensively in both human and veterinary medicine. Poor metabolization and high chemical stability of these synthetic antibiotics led to their presence in several environmental compartments. This undesirable behavior may promote the spread of resistance mechanisms due to concomitant exposure to bacteria. Therefore, the biotransformation of ciprofloxacin, one of the most prescribed fluoroquinolones in human medicine, by the ascomycetous soft rot fungus X. longipes was investigated in detail. Submerged cultivation of the fungus allowed for high-yield formation of four biotransformation products. These compounds were subsequently purified by preparative high-performance liquid chromatography. Applying accurate mass spectrometry and nuclear magnetic resonance spectroscopy, desethylene-ciprofloxacin, desethylene-N-acetyl-ciprofloxacin, N-formyl-ciprofloxacin and N-acetyl-ciprofloxacin were unambiguously identified. N-acetylation and N-formylation of the drug led to a 75-88% reduction of the initial antibacterial activity, whereas a breakdown of the piperazine substituent resulted in almost inactive products. These findings suggest an important role in the inactivation and degradation of this and other synthetic compounds in the environment.

Ciprofloxacin derivatives and their antibacterial activities

Bacterial infections represent a significant health threat globally, and are responsible for the majority of hospital-acquired infections, leading to extensive mortality and burden on global healthcare systems. The second generation fluoroquinolone ciprofloxacin which exhibits excellent antimicrobial activity and pharmacokinetic properties as well as few side effects is introduced into clinical practice for the treatment of various bacterial infections for around 3 decades. The emergency and widely spread of drug-resistant pathogens making ciprofloxacin more and more ineffective, so it's imperative to develop novel antibacterials. Numerous of ciprofloxacin derivatives have been synthesized for seeking for new antibacterials, and some of them exhibited promising potency. This review aims to summarize the recent advances made towards the discovery of ciprofloxacin derivatives as antibacterial agents and the structure-activity relationship of these derivatives was also discussed.

Intravenous anti-MRSA phosphatiosomes mediate enhanced affinity to pulmonary surfactants for effective treatment of infectious pneumonia

The aim of this study was to develop PEGylated phosphatidylcholine (PC)-rich nanovesicles (phosphatiosomes) carrying ciprofloxacin (CIPX) for lung targeting to eradicate extracellular and intracellular methicillin-resistant Staphylococcus aureus (MRSA). Soyaethyl morphonium ethosulfate (SME) was intercalated in the nanovesicle surface with the dual goals of achieving strengthened bactericidal activity of CIPX-loaded phosphatiosomes and delivery to the lungs. The isothermal titration calorimetry (ITC) results proved the strong association of SME phosphatiosomes with pulmonary surfactant. We demonstrated a superior anti-MRSA activity of SME phosphatiosomes compared to plain phosphatiosomes and to free CIPX. A synergistic effect of CIPX and SME nanocarriers was found in the biofilm eradication. SME phosphatiosomes were readily engulfed by the macrophages, restricting the intracellular MRSA count by 1-2 log units. SME phosphatiosomes efficiently accumulated in the lungs after intravenous injection. In a rat model of lung infection, the MRSA burden in the lungs could be decreased by 8-fold after SME nanosystem application.

Piperazine scaffold: A remarkable tool in generation of diverse pharmacological agents

Piperazine is one of the most sought heterocyclics for the development of new drug candidates. This ring can be traced in a number of well established, commercially available drugs. Wide array of pharmacological activities exhibited by piperazine derivatives have made them indispensable anchors for the development of novel therapeutic agents. The review herein highlights the therapeutic significance of piperazine derivatives. Various therapeutically active piperazine derivatives developed by several chemists are reported here.