Electrochemical Detection of Melphalan in Biological Fluids Using a g-C3N4@ND-COOH@MoSe2 Modified Electrode Complemented by Molecular Docking Studies with Cellular Tumor Antigen P53.

Melphalan (Mel) is a potent alkylating agent utilized in chemotherapy treatments for a diverse range of malignancies. The need for its accurate and timely detection in pharmaceutical preparations and biological samples is paramount to ensure optimized therapeutic efficacy and to monitor treatment progression. To address this critical need, our study introduced a cutting-edge electrochemical sensor. This device boasts a uniquely modified electrode crafted from graphitic carbon nitride (g-C3N4), decorated with activated nanodiamonds (ND-COOH) and molybdenum diselenide (MoSe2), and specifically designed to detect Mel with unparalleled precision. Our rigorous testing employed advanced techniques such as cyclic voltammetry and differential pulse voltammetry. The outcomes were promising; the sensor consistently exhibited a linear response in the range of 0.5 to 12.5 µM. Even more impressively, the detection threshold was as low as 0.03 µM, highlighting its sensitivity. To further enhance our understanding of Mel's biological interactions, we turned to molecular docking studies. These studies primarily focused on Mel's interaction dynamics with the cellular tumor antigen P53, revealing a binding affinity of -5.0 kcal/mol. A fascinating observation was made when Mel was covalently conjugated with nanodiamond-COOH (ND-COOH). This conjugation resulted in a binding affinity that surged to -10.9 kcal/mol, clearly underscoring our sensor's superior detection capabilities. This observation also reinforced the wisdom behind incorporating ND-COOH in our electrode design. In conclusion, our sensor not only stands out in terms of sensitivity but also excels in selectivity and accuracy. By bridging electrochemical sensing with computational insights, our study illuminates Mel's intricate behavior, driving advancements in sensor technology and potentially revolutionizing cancer therapeutic strategies.

Nanodiamond (ND)-Based ND@CuAl2O4@Fe3O4 electrochemical sensor for Tofacitinib detection: A unified approach to integrate experimental data with DFT and molecular docking.

Tofacitinib (TOF) is gaining recognition as a potent therapeutic agent for a variety of autoimmune disorders, including rheumatoid arthritis and psoriasis. Ensuring precise drug concentration control during treatment necessitates a rapid and sensitive detection method. This study introduces a novel electrochemical sensor employing a composite of nanodiamond (ND), copper aluminate spinel oxide (CuAl2O4), and iron (II, III) oxide (Fe3O4) as modified materials for efficient TOF detection. Extensive analyses using physicochemical and electrochemical techniques were carried out to characterize the morphological, structural, and electrochemical properties of the ND@CuAl2O4@Fe3O4 composite. Thereafter, various voltammetric methods were utilized to evaluate the electrochemical behavior of the ND@CuAl2O4@Fe3O4-modified glassy carbon electrode (GCE) concerning TOF determination. The fabricated electrode showcased superior performance in electrochemical TOF detection in a buffered solution (pH = 5), achieving a remarkably low detection limit of 7.8 nM and a linear response from 0.05 µM to 13.21 µM. Furthermore, applying the modified electrode as an electrochemical sensor exhibited exceptional selectivity, stability, and practicality in determining TOF in pharmaceutical and biological samples. Alongside the sensor development, this study conducted a thorough investigation using Density Functional Theory (DFT) for the geometry optimization of TOF and the TOF-ND complex. Consequently performed molecular docking studies using Janus Kinase 1 (JAK1) (PDB ID: 3EYG) and JAK3 (PDB ID: 3LXK) indicated higher interaction of the TOF-ND conjugate with the JAKs, reflected by binding energies of -12.9 kcal/mol and -11.7 kcal/mol for JAK1 and JAK3 respectively, compared to -7.0 kcal/mol and -6.9 kcal/mol for TOF alone. These findings illustrate the potential of the ND-based ND@CuAl2O4@Fe3O4 composite as a proficient sensing material for TOF detection and the merits of DFT in providing a detailed understanding of the interactions at play. This pioneering research holds promise for real-time TOF monitoring, which will advance personalized treatment strategies and improve therapeutic outcomes for patients with autoimmune disorders.

Computational insights into bis-N,N-dimethylaniline based D-π-A photosensitizers bearing divergent-type of π-linkers for DSSCs.

In this study, theoretically designed D-π-A derivatives containing different π-subunits as linkers were investigated to enlighten their potential applicability in photovoltaic applications. For this aim, we first focused on clarifying the effect of tailored π-linker scaffolds on the frontier orbital energies of the investigated photosensitizers. In the concomitant step, global descriptors, TiO2 adsorption, maximum absorbance wavelength, light-harvesting efficiency (LHE), energy conversion efficiency (η), short circuit current density (JSC), open circuit photovoltage (VOC), fill factor (FF), and reorganization energy (λe, λh, λT) values, electron density differentiation maps (EDDM), transition density matrices (TDM), fragmental contributions on electron-hole overlap were investigated in detail. Based on the trend of the calculated properties, 2,3-dimethylthieno [3,4-b]pyrazine (D-Ɛ3-δn-A; n = 1-3) and 5-isobutyl-10,11-dimethyl-10,11-dihydro-5H-pyrrolo [3,4-e]thieno [2',3':4,5]pyrrolo [3,2-g]thieno [3,2-b]indole (D-Ɛ6-δn-A; n = 1-3) bearing molecules were identified as the best-suited and improved dye candidates for DSSC applications. Following the prediction of photovoltaic properties for the pristine dye molecules, our consecutive efforts have contributed to a similar calculation protocol comprising DFT and subsequent TD-DFT computations for the D-Ɛn-δn-A@Ti5O10 clusters to elucidate the interaction of the investigated photosensitizers with the semiconductor layer (TiO2).

PIDA-mediated Oxidative Decarboxylation of Oxamic Acids. The Role of Radical Acidity Enhancement.

The PIDA-mediated oxidative decarboxylation of oxamic acids in the presence of alcohols is shown to afford the corresponding urethanes under thermal conditions. Computational and experimental mechanistic exploration allows to rationalize the different reactivity of PIDA as compared to related cyclic BI-OAc and highlights the importance of the enhanced acidity of the proton in the carbamoyl radical intermediate.

Design, synthesis, spectroscopic characterizations, in vitro pancreatic lipase as well as tyrosinase inhibition evaluations and in silico analysis of novel aryl sulfonate-naphthalene hybrids.

One of the primary purposes of this study is to synthesize new aryl sulfonate-naphthalene hybrid structures possessing divergent electron-withdrawing and electron-releasing functional groups. Following the improved reaction conditions, we successfully gathered ten distinct sulfonate derivatives (3a-j) with good yields. The synthesized naphthalene-based sulfonate derivatives were then characterized using appropriate analytical methods (FT-IR, 1H-NMR, 13C-NMR, HRMS, and elemental analysis). Additionally, in vitro and in silico enzyme inhibitory properties of the prepared aryl sulfonate-naphthalene hybrid structures were evaluated against pancreatic lipase and tyrosinase enzymes. Corresponding in vitro enzyme activity investigations revealed that the produced compounds inhibit pancreatic lipase and tyrosinase enzymes significantly. According to the lowest IC50 values, 3h (95.3 ± 4.0 µM) demonstrated the most effective inhibition against pancreatic lipase, whereas 3a (40.8 ± 3.3 µM) was found as the most effective inhibition against the tyrosinase. According to in silico studies, 3a exhibited the highest affinity value (-9.9 kcal/mol) against pancreatic lipase, whereas 3f demonstrated the best affinity value (-8.7 kcal/mol) against tyrosinase.Furthermore, we investigated various structural and physicochemical properties of the target molecules, namely frontier orbital' (HOMO, LUMO, and bandgap) energies (including their corresponding contour plots), global reactivity descriptors (ionization energy and electron affinity), and electronegativity values gathered from ground-state (GS) density functional theory (DFT) calculations. These investigations demonstrated that the observed electrostatic interactions effectively contributed to the studied molecules' experimentally demonstrated enzyme inhibition potential. Also, ADMET studies were evaluated to enlighten the molecular interactions of the compounds with the enzymes.Communicated by Ramaswamy H. Sarma.

Correction: Oxamic acids: useful precursors of carbamoyl radicals.

Correction for 'Oxamic acids: useful precursors of carbamoyl radicals' by Ikechukwu Martin Ogbu et al., Chem. Commun., 2022, 58, 7593-7607, https://doi.org/10.1039/D2CC01953A.

Oxamic acids: useful precursors of carbamoyl radicals.

This review article describes the recent development in the chemistry of carbamoyl radicals generated from oxamic acids. This mild and efficient method compares well with previous methods of generation of these nucleophilic radicals. The oxidative decarboxylation of oxamic acids can be mediated through thermal, photochemical, electrochemical or photoelectrochemical means, generating carbamoyl radicals, which may further add to unsaturated systems to provide a broad range of important amides. Oxidative decarboxylation of oxamic acids also offers a straightforward entry for the preparation of urethanes, ureas, and thioureas.

Imidazole substituted Zinc(II) phthalocyanines for co-catalyst-free photoelectrochemical and photocatalytic hydrogen evolution: influence of the anchoring group.

Novel zinc phthalocyanine derivatives, ZnPc-1 and ZnPc-2, consisting of one and four imidazole units, respectively, have been synthesized and utilized as panchromatic photosensitizers for photocatalytic and photoelectrochemical H2 evolution. The effect of the imidazole-anchoring group on the photocatalytic H2 production has been compared with ZnPc-3, which possesses a carboxylic acid unit as the anchoring group. ZnPc-1/TiO2 shows the best photoactivity with the highest H2 evolution rate of 0.4006 mmol g-1 h-1, which is much higher than that of ZnPc-2/TiO2 and ZnPc-3/TiO2 (0.3319 mmol g-1 h-1 and 0.3555 mmol g-1 h-1, respectively). After 20 h of irradiation, ZnPc-1 produces an H2 production rate of 3.4187 mmol g-1 with a turnover number (TON) of 14863 and a solar-to-hydrogen energy (STH) conversion efficiency of 1.03%, without using a co-catalyst.

Urethanes synthesis from oxamic acids under electrochemical conditions.

Urethane synthesis via oxidative decarboxylation of oxamic acids under mild electrochemical conditions is reported. This simple phosgene-free route to urethanes involves an in situ generation of isocyanates by anodic oxidation of oxamic acids in an alcoholic medium. The reaction is applicable to a wide range of oxamic acids, including chiral ones, and alcohols furnishing the desired urethanes in a one-pot process without the use of a chemical oxidant.

Comparative cation sensing properties of a newly designed urea linked ferrocene-benzimidazole dyad: a DFT study.

Herein, our primary motivation was to elucidate the electronic and physicochemical properties of a novel molecular dyad consisting of ferrocene (Fc; electron donor), urea (u; linker), and amphoteric benzimidazole (BI; electron acceptor) entities. The sensor responses were investigated for various divalent transition metal cations (Mn2+, Fe2+, Co2+, Ni2+, Cu2+, and Zn2+) and the selectivity of this cationophore molecule (Fc-u-BI) to copper ion (Cu2+) was demonstrated by using B3LYP/LANL2DZ method. According to the thermochemical calculations, we justified that Fc-u-BI⋯Cu2+ reached to the lowest binding energy (∆E), enthalpy (∆H), and Gibbs free energy (∆G) changes. In the light of the calculated global descriptors, Fc-u-BI⋯Cu2+ was found to be the softer and thus the most reactive complex. The complex stabilities and their corresponding non-covalent interactions were also investigated by NBO and NCI analyses, respectively. The mechanistic insight into metal cation sensing by the modeled cationophore dyad.

Eosin-Mediated Alkylsulfonyl Cyanation of Olefins.

Eosin-Y (EY)-mediated alkylsulfonyl cyanation of olefins was shown to afford alkylsulfonyl nitriles in good yields. On the basis of transient absorption spectroscopy, the reaction was shown to proceed via photoinduced electron transfer from 3EY* to an O-cyanated derivative of the photocatalyst, formed in situ, with generation of the corresponding sulfinate that is oxidized by EY•.+ into a sulfonyl radical. Addition of the latter on the olefin, followed by a radical cyano group transfer, then furnished the nitrile along with a RSO2 radical sustaining the radical chain.