A detailed investigation of the spectral and photophysical properties of minocycline (MC) in water at different pHs, solvents of different polarity, and micellar surfactant solutions was carried out in this study. An unusual behavior was highlighted with respect to other tetracyclines due to the presence of an additional dimethylamino group in the MC molecular structure. In particular, four equilibrium constants associated with mono-deprotonation reactions were characterized by steady-state spectroscopy. Femtosecond time-resolved pump-probe and fluorescence up-conversion measurements allowed the dynamics of the lowest excited singlet state of the five different acid-base species of MC to be characterized in terms of lifetimes and transient spectra. Two emissive species associated with keto-enol tautomerism resulting from excited-state intramolecular proton transfer (ESIPT) were revealed with time constants of a few and tens of picoseconds. TD-DFT quantum mechanical calculations were also performed to define the state order and nature of the differently protonated species, together with their absorption spectra. The role of pH proved to be fundamental in modulating the drug charge and therefore the interaction with cationic micelles where the neutral form of MC, that is the biologically active one, resulted efficiently included.
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http://dx.doi.org/10.1021/acs.jpca.5b12707 | DOI Listing |
J Environ Manage
December 2024
State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai, 200092, PR China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai, 200092, PR China.
Photocatalysis is an effective method for removing tetracycline antibiotics, which are important precursors to the potential carcinogen N-nitrosodimethylamine (NDMA). Herein, a BiOCl/ZnInS heterojunction was successfully synthesized using a simple hydrothermal method. This heterojunction was applied for the first time to degrade various tetracycline antibiotics and reduce NDMA formation potential (NDMA-FP) under visible-light irradiation.
View Article and Find Full Text PDFJ Colloid Interface Sci
March 2025
Biological Physics Laboratory, Department of Physics and Astronomy, School of Natural Science, The University of Manchester, Oxford Road, Manchester M13 9PL UK. Electronic address:
Antimicrobial resistance (AMR) is fast becoming a major global challenge in both hospital and community settings as many current antibiotics and treatment processes are under the threat of being rendered less effective or ineffective. Synergistic combination of an antibiotic and an aiding agent with a different set of properties provides an important but largely unexploited option to 'repurpose' existing biomaterial's space while addressing issues of potency, spectrum, toxicity and resistance in early stages of antimicrobial drug discovery. This work explores how to combine tetracycline/minocycline (TC/MC) with a broad-spectrum antimicrobial lipopeptide that has been designed to improve the efficiency of membrane targeting and intramembrane accumulation, thereby enhancing antimicrobial efficacy.
View Article and Find Full Text PDFArch Gerontol Geriatr
February 2025
Division of microbiology, Tulane National Primate Research Center, Tulane University, Covington, Louisiana, USA; Department of Microbiology and Immunology, Tulane University School of Medicine, New Orleans, Louisiana, USA. Electronic address:
Objective: There is a lack of information on the molecular mechanisms by which steroid hormones (testosterone, estrogen, and progesterone) regulate cognitive impairment. Thus, we aimed to identify the protective effects of steroid hormones on cognitive function.
Methods: We analyzed the literature on the molecular mechanisms, biological activities, physicochemical properties, and pharmacokinetics of steroid hormones.
Int J Prev Med
September 2024
Division of Toxicology, Department of Comparative Bioscience, Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran.
Background: Previous evidence indicates that tramadol (TRA) can lead to neurodegenerative events and minocycline (MIN) has neuroprotective properties.
Aim Of The Study: The current research evaluated the neuroprotective effects of MIN for TRA-promoted neurodegeneration.
Methods: Sixty adult male rats were placed into the following groups: 1 (received 0.
Drug Dev Ind Pharm
October 2024
Department of Basic Sciences of Engineering, Kayseri University, Kayseri, Turkey.
Objective: It was aimed to formulate minocyline. HCI loaded electrospun polyurethane/collagen (PU/Col) and polyurethane/collagen/polycaprolactone (PU/Col/PCL) nanofibers are intended for use as a wound dressing.
Methods: The effect of polymer ratio and addition of PCL on the morphology, diameter, drug delivery, encapsulation efficiency, mechanical properties, antibacterial activity against and , cytotoxicity, cell adhesion and proliferation were investigated.
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