RSC Advances

Ahmadpour, Najmeh; Sayadi, Mohammad Hossein; Homaeigohar, Shahin

doi: 10.1039/d3ra90057fpmid: 37396833

Correction for ‘A hierarchical Ca/TiO2/NH2-MIL-125 nanocomposite photocatalyst for solar visible light induced photodegradation of organic dye pollutants in water’ by Najmeh Ahmadpour et al., RSC Adv., 2020, 10, 29808–29820, https://doi.org/10.1039/D0RA05192F.

Foroutan, Farzad; Kyffin, Benjamin A.; Nikolaou, Athanasios; Merino-Gutierrez, Jorge; Abrahams, Isaac; Kanwal, Nasima; Knowles, Jonathan C.; Smith, Andrew J.; Smales, Glen J.; Carta, Daniela

doi: 10.1039/d3ra02958apmid: 37396829

Mesoporous glasses are a promising class of bioresorbable biomaterials characterized by high surface area and extended porosity in the range of 2 to 50 nm. These peculiar properties make them ideal materials for the controlled release of therapeutic ions and molecules. Whilst mesoporous silicate-based glasses (MSG) have been widely investigated, much less work has been done on mesoporous phosphate-based glasses (MPG). In the present study, MPG in the P2O5CaONa2O system, undoped and doped with 1, 3, and 5 mol% of Cu ions were synthesized via a combination of the solgel method and supramolecular templating. The non-ionic triblock copolymer Pluronic P123 was used as a templating agent. The porous structure was studied via a combination of Scanning Electron Microscopy (SEM), Small-Angle X-ray Scattering (SAXS), and N2 adsorptiondesorption analysis at 77 K. The structure of the phosphate network was investigated via solid state 31P Magic Angle Spinning Nuclear Magnetic Resonance (31P MAS-NMR) and Fourier Transform Infrared (FTIR) spectroscopy. Degradation studies, performed in water via Inductively Coupled Plasma-Optical Emission Spectroscopy (ICP-OES), showed that phosphates, Ca2+, Na+ and Cu ions are released in a controlled manner over a 7 days period. The controlled release of Cu, proportional to the copper loading, imbues antibacterial properties to MPG. A significant statistical reduction of Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli) bacterial viability was observed over a 3 days period. E. coli appeared to be more resistant than S. aureus to the antibacterial effect of copper. This study shows that copper doped MPG have great potential as bioresorbable materials for controlled delivery of antibacterial ions.

SÖĞÜTLÜ, İnci; Saeed, Shakir Mahmood; Adil, Mohaned; Yadav, Anupam; Mahmood, Evan Abdulkareem; Saadh, Mohamed J.

doi: 10.1039/d3ra03092jpmid: 37396827

Aqueous two-phase systems (ATPSs) have long been recognized as versatile and efficient tools for the extraction of biomolecules, including amino acids. Recent advancements in the field have introduced a novel approach by utilizing deep eutectic solvents (DES) to form ATPs. This study aimed to determine the phase diagrams for an ATPS made of polyethylene glycol dimethyl ether 250 and two types of NADESs, namely choline chloride as a hydrogen bond acceptor (HBA), and either sucrose or fructose as a hydrogen bond donor (HBD) with a molar ratio of 1 : 2. The measured tie-line results revealed that the hydrogen bonds of NADES may not be entirely disrupted in aqueous solutions, and thus, these ATPSs act as ternary-like systems. Additionally, the binodal data were fitted using two semi-empirical equations, namely Merchuk and Zafarani-Moattar et al. equations. Furthermore, the ATPSs mentioned above were applied to extract three amino acids, namely L-arginine, L-phenylalanine, and L-tyrosine, and demonstrated good extraction levels. Finally, the Diamond–Hsu equation and its modified version were utilized to correlate the experimental partition coefficients of the amino acids. These advancements pave the way for the development of improved extraction methodologies and the exploration of new applications in the field of biotechnology, pharmaceuticals, and beyond.

Asaftei, Mihaela; Lucidi, Massimiliano; Cirtoaje, Cristina; Holban, Alina-Maria; Charitidis, Costas A.; Yang, Fang; Wu, Aiguo; Stanciu, George A.; Salam, zge; Lazar, Veronica; Visca, Paolo; Stanciu, Stefan G.

doi: 10.1039/d3ra01745apmid: 37396836

The fast and global spread of bacterial resistance to currently available antibiotics results in a great and urgent need for alternative antibacterial agents and therapeutic strategies. Recent studies on the application of nanomaterials as antimicrobial agents have demonstrated their potential for the management of infectious diseases. Among the diverse palette of nanomaterials currently used in biomedical applications, carbon nanotubes (CNTs) have gained massive interest given their many valuable properties, such as high thermal and electrical conductivity, tensile strength, flexibility convenient aspect ratio, and low fabrication costs. All these features are augmented by facile conjugation with functional groups. CNTs are currently available in many configurations, with two main categories being single-walled and multi-walled CNTs, depending on the number of rolled-up single-layer carbon atoms sheets making up the nanostructure. Both classes have been identified over the past years as promising antibacterial agents but the current level of understanding of their efficiency still harbors many pending questions. This mini-review surveys recent progress on the topic of antibacterial effects of CNTs and examines the proposed mechanisms of action(s) of different CNT typologies, placing the main focus on past studies addressing the antibacterial activity on Staphylococcus aureus and Escherichia coli, two prototypical Gram-positive and Gram-negative pathogens, respectively.

Omara, Mariam; Hagras, Mohamed; Elsebaie, Mohamed M.; Abutaleb, Nader S.; El-Din, Hanzada T. Nour; Mekhail, Maria O.; Attia, Ahmed S.; Seleem, Mohamed N.; Sarg, Marwa T.; Mayhoub, Abdelrahman S.

doi: 10.1039/d3ra02778cpmid: 37425632

Antimicrobial resistance has become a concern as a worldwide threat. A novel scaffold of phenylthiazoles was recently evaluated against multidrug-resistant Staphylococci to control the emergence and spread of antimicrobial resistance, showing good results. Several structural modifications are needed based on the structure–activity relationships (SARs) of this new antibiotic class. Previous studies revealed the existence of two key structural features essential for the antibacterial activity, the guanidine head and lipophilic tail. In this study, a new series of twenty-three phenylthiazole derivatives were synthesized utilizing the Suzuki coupling reaction to explore the lipophilic part. The in vitro antibacterial activity was evaluated against a range of clinical isolates. The three most promising compounds, 7d, 15d and 17d, with potent MIC values against MRSA USA300 were selected for further antimicrobial evaluation. The tested compounds exhibited potent results against the tested MSSA, MRSA, and VRSA strains (concentration: 0.5 to 4 μg mL−1). Compound 15d inhibited MRSA USA400 at a concentration of 0.5 μg mL−1 (one-fold more potent than vancomycin) and showed low MIC values against ten clinical isolates, including linezolid-resistant strain MRSA NRS119 and three vancomycin-resistant isolates VRSA 9/10/12. Moreover, compound 15d retained its potent antibacterial activity using the in vivo model by the burden reduction of MRSA USA300 in skin-infected mice. The tested compounds also showed good toxicity profiles and were found to be highly tolerable to Caco-2 cells at concentrations of up to 16 μg mL−1, with 100% of the cells remaining viable.

Elshamy, Abdelsamed I.; Mohamed, Tarik A.; Swapana, Ningombam; Kasai, Yusuke; Noji, Masaaki; Efferth, Thomas; Imagawa, Hiroshi; Hegazy, Mohamed-Elamir F.; Umeyama, Akemi

doi: 10.1039/d3ra03146bpmid: 37396835

Isodon ternifolius (D.Don) Kudô is an important Asian herb used in traditional medicine against several diseases. Nineteen compounds were isolated from the dichloromethane–methanol (1 : 1) extract of I. ternifolius roots, including ten new α-pyrone derivatives, named ternifolipyrons A–J. The chemical structures of the isolates were determined by a combination of 1D and 2D NMR, along with LR- and HRMS spectroscopy. The absolute configurations of the α-pyrone derivatives were constructed based upon the X-ray signal crystal of the bromobenzoyl derivative of 1 as well as the electronic circular dichroism (ECD). All isolates (1–19) were investigated for their growth-inhibitory potential towards CCRF-CEM-leukemia cells at a fixed concentration of 30 μM. The compounds which exerted more than 50% inhibition at this concentration, compounds (7, 10, 12, 15–17), were tested at a different concentration range to determine their IC50 values in CCRF-CEM leukemia, MDA-MB-231 triple-negative breast cancer, and MCF7 breast cancer cell lines. Ursolic acid (16) showed the most potent activity against the three cancer cell lines with IC50 values of 8.37, 18.04, and 18.93 μM, respectively.

Hirth, Sabine; Wohlleben, Wendel; Waindok, Hubert

doi: 10.1039/d3ra02232cpmid: 37448780

Afreen, Asma; Ahmed, Zaheer; Khalid, Nauman

doi: 10.1039/d2ra07338bpmid: 37396834

A novel exopolysaccharide (EPS) was obtained from Levilactobacillus brevis NCCP 963 isolated from a black carrot drink named “kanji”. The culture conditions for maximum EPS yield were explored by the Plackett–Burman (PB) design and response surface methodology (RSM) along with the fractional characterization and antioxidant potential of EPSs. The PB design screened out five significant factors, namely, glucose, sucrose, tryptone, CaCl2, and di-potassium phosphate out of eleven independent factors. The RSM indicated glucose and CaCl2 as significant factors in EPS production and a maximum EPS production of 968.89 mg L−1 was obtained at optimized levels of 10.56% glucose, 9.23% sucrose, 0.75% tryptone, 0.446% CaCl2, and 0.385% K2HPO4. A R2 value above 93% indicates higher variability, depicting the validity of the model. The obtained EPS has a molecular weight of 5.48 × 104 Da and is a homopolysaccharide in nature with glucose monosaccharides. FT-IR analysis showed significant band stretching of C–H, O–H, C–O and C–C and indicated the β-glucan nature of EPSs. The comprehensive antioxidant investigation showed significant in vitro DPPH, ABTS, hydroxyl, and superoxide scavenging capacity with EC50 values of 1.56, 0.31, 2.1, and 6.7 mg mL−1 respectively. Curd formation from the resulting strain prevented syneresis.

Luo, Fenqiang; Guo, Meng; Zheng, Liyan; Cai, Zhixiong

doi: 10.1039/d3ra02868bpmid: 37396831

An efficient fluorescence-enhanced probe was developed for detecting cyanide ions (CN−) based on a tetraphenylethene coordinated copper-iodide complex (named CIT-Z). The coordination polymers (CPs) prepared were (Z)-1,2-diphenyl-1,2-bis[4-(pyridin-3-ylmethoxy)phenyl]ethene (1Z) and a CuI cluster, where the tetraphenylethylene (TPE) pyridine derivatives acted as organic ligands and the CuI cluster acted as a metal center. The higher-dimensional CIT-Z exhibited a 3-fold-interpenetrating network structure with excellent optical properties and chemical stability. This study also provides insights into the mechanism behind the fluorescence enhancement, which is attributed to the competitive coordination between CN− and the ligands. The probe showed high selectivity and sensitivity towards CN−, with a detection limit of 0.1 μM and good recovery in the real water samples.

Hanzl, Lukáš; Vinklárek, Jaromír; Dostál, Libor; Císařová, Ivana; Litecká, Miroslava; Honzíček, Jan

doi: 10.1039/d3ra03383jpmid: 37396830

This study reports the stabilizing effect of an intramolecularly coordinated thioether function in propene complexes of the general formula [{η5:κS-C5H4(CH2)2SR}M(CO)2(η2-C2H3Me)][BF4] (M = Mo, W; R = Et, Ph). They are formed by protonation of allyl analogues [{η5-C5H4(CH2)2SR}M(CO)2(η3-C3H5)] by tetrafluoroboric acid in non-coordinating solvents. In contrast to analogues with unsubstituted Cp ligands, these propene complexes are isolable in a pure form and characterized by NMR spectroscopy. The molybdenum compounds are stable at low temperature and the propene ligand can easily be exchanged by thioethers or acetonitrile. Several representatives of the reaction products were characterized by X-ray structure analysis. The stabilization effect in tungsten complexes [{η5:κS-C5H4(CH2)2SR}W(CO)2(η2-C2H3Me)][BF4] (R = Et, Ph) was unusually high. The compounds are long-term stable at room temperature and do not undergo ligand exchange reactions even with strong chelators such as 1,10-phenanthroline. The molecular structure of the tungsten propene complex was confirmed by X-ray diffraction analysis on a single crystal.