Analytical investigation of the influence of ornidazole on the native protein fluorescence

Investigation of the molecular interaction between apraclonidine, an α2-adrenergic receptor agonist, and bovine serum albumin using fluorescence and molecular docking techniques

Apraclonidine (APR) is a potent and selective α2-adrenergic receptor agonist used in the diagnosis of Horner's Syndrome, and the residuals of APR that accumulate in tissues of animals can cause central nervous and cardiovascular systems influences in humans. Therefore, to understand the influence of APR on human health, we examined the interaction of APR with the carrier protein in plasma, bovine serum albumin (BSA). The BSA fluorescence signal was quenched due to the APU-BSA complex formation and a weak binding affinity was estimated between APR and BSA. The inclusion of fluorescence, UV-vis absorption, molecular docking, and dynamics simulation techniques employed to broadly investigate the combination of APR with BSA at typical physiological conditions. The thermodynamic results revealed that enthalpy (ΔH0) and entropy (ΔS0) changes were computed as +11.14 kJ mol-1 and +97.56 J mol-1 K-1, respectively, which represented the binding is principally entropy-driven and the hydrophobic forces acting a significant role in the reaction. Analysis of synchronous and 3-D fluorescence signals revealed microenvironmental variations close to BSA's Trp and Tyr residues upon APR addition. Both the competitive site marker as well as molecular docking results detected that APR exhibited a stronger binding affinity towards Drug Site 2 (DS2) compared to Drug Site 1 (DS1).

Sulfur and nitrogen co-doped carbon quantum dots as fluorescent probes for the determination of some pharmaceutically-important nitro compounds

In this study, highly fluorescent sulfur and nitrogen co-doped carbon quantum dots (SN-CQDs) were synthesized by a simple one-pot hydrothermal method using thiosemicarbazide and citric acid as starting materials. Various spectroscopic and microscopic techniques were applied to characterize the prepared SN-CQDs. The synthesized SN-CQDs' maximum fluorescence emission was obtained at 430 nm after excitation at 360 nm. Rifampicin (RFP), tinidazole (TNZ), ornidazole (ONZ), and metronidazole (MNZ) all quantitatively and selectively quenched the SN-CQDs' native fluorescence, which was the base-for their-spectrofluorimetric estimation without the need for any tedious pre-treatment steps or high-cost instrumentation. SN-CQDs demonstrated a "turn-off" fluorescence response to RFP, TNZ, ONZ, and MNZ over the ranges of 1.0-30.0, 10.0-200.0, 6.0-200.0, and 5.0-100.0 μM with detection limits of 0.31, 1.76, 0.57, and 0.75 μM and quantitation limits of 0.93, 5.32, 1.74, and 2.28 μM respectively. The suggested method was successfully used to determine the investigated drugs in their commercial dosage forms. The method was further extended to their determination in spiked human plasma samples, with satisfactory mean % recoveries (99.44-100.29) and low % RSD values (< 4.52). The mechanism of fluorescence quenching was studied and discussed. The suggested method was validated in accordance with ICH recommendations.

In-situ preparation of CuO nanoparticles decorated In2O3 pn heterojunction composite for the photoelectrochemical detection of ornidazole

The eco-friendly synthesis of metal oxides pn junction composite with high visible light absorption and its photoelectrochemical monitoring on antibiotics is reported. The In2O3-CuO pn heterojunction composite was successfully prepared by in-situ hydrothermal decoration of CuO on the prepared In2O3 using a simple reflux method. The obtained nanorods like In2O3-CuO pn heterojunction exhibited high conductivity with excellent stability for the facilitated photoelectrochemical detection of ornidazole (ONZ) that plays a role in aquatic toxicology. The photo-stability and optical characteristics of the In2O3-CuO heterojunction composite were analyzed through photocurrent and UV-visible studies. Mechanism of ONZ signaling has been proposed with appropriate band levels derived by Mott-Schottky analysis. An optimized In2O3-CuO heterojunction detects ONZ in the range 0.05-65.3 nM with 0.0092 nM as the limit of detection at - 0.45 V (vs. Ag/AgCl) working potential. The practical applicability of the sensor device was tested in chicken meat, human urine, and lake water samples containing ONZ. The recoveries of real samples were above 95% and results obtained were compared with electrochemical methods.

A pH-responsive hydrogel with potent antibacterial activity against both aerobic and anaerobic pathogens

A pH-responsive hydrogel prepared by oxidized dextran with aminoglycoside and an ornidazole analogue can kill both aerobic and anaerobic pathogens.