Amine Moiety Research Articles

Aminophosphine PNH complexes of Mn(I), Fe(II), and Co(II) and evaluation of their activities in the transfer hydrogenation of nitriles.

A series of Mn(I), Fe(II), and Co(II) complexes with PNH ligands bearing secondary amine functionality were prepared and tested in the catalytic transfer hydrogenation of nitriles using ammonia borane as a hydrogen source. Among all tested complexes, a tetracoordinate Fe(II) bromide, (PNH)FeBr2, proved the most effective, representing a rare example of a highly active iron-based catalytic system for transfer hydrogenation reactions beyond carbonyl compounds and the first example of the iron catalyst for the transfer hydrogenation of nitriles to the corresponding primary amines. Mechanistic studies point out a metal-ligand cooperative mechanism enabled by the secondary amine moiety of the PNH ligand.

Synthesis and Characterization of Novel Diethylenetriamine Based Sulfonamide Ligands and Their Bidentate Platinum(II) Complexes Toward Anticancer Drug Leads

Diethylenetriamine (dienH) is one of the most biologically compatible chelate frameworks. Its hydrophilic amine moiety was functionalized via N-sulfonylation with sulfonyl chloride to produce two novel ligands; N(SO2)(bzd)dienH (L1) and N(SO2)(4-Mebip)dienH (L2) and two reported ligands; N(SO2)(1-nap)dienH (L3) and N(SO2)(2-nap)dienH (L4). Treatment of cis-Pt(DMSO)2Cl2with L1, L2, L3 and L4 afforded four novel neutral complexes [Pt(N(SO2)(bzd)dienH)Cl2] (C1), [Pt(N(SO2)(4-Mebip)dienH)Cl2] (C2), [Pt(N(SO2)(1-nap)dienH)Cl2] (C3) and [Pt(N(SO2)(2-nap)dienH)Cl2] (C4) respectively. All synthesized compounds were characterized by 1H NMR, UV-Vis, FTIR and fluorescence spectroscopy. Aliphatic diethylenetriamine protons of the ligands appeared in the 3.00 -2.30 ppm region in 1H NMR spectra recorded in DMSO-d6. Upon complexation, the appearance of two broad NH peaks between 5.00 -7.00 ppm region and another broad peak between 7.00-8.00 ppm confirmed the bidentatedenticity of the ligands vs tridentate. The formation of metal complexes was further supported by FTIR spectra in which the S-N stretching band for the metal complexes appears at lower wavenumbers compared to that of the corresponding free ligands. Emission spectra were recorded in methanol and intense fluorescence properties were observed in the 331-364 nm range for the ligands, whereas the corresponding Pt complexes showed quenched fluorescence. In vitro cytotoxic effects were investigatedusing sulforhodamine B assay, where L2 (< 10 μg/mL) demonstrated increased levels of cytotoxicity followed by C2 (< 25 μg/mL) and C4 (< 50 μg/mL) to non-small cell lung cancer cells in dose and time-dependent manner, with less or no cytotoxic effects to normal lung cells tested. Among the compounds tested, C1 and C3 displayed comparatively lower but more potent cytotoxic effects on lung cancer cells. Notably, these compounds did not exhibit any toxicity towards normal cells. Thus, they hold promise as lead compounds for the development of chemotherapeutic agents targeting lung cancer.
 Keywords: Platinum, Sulfonamide, Biphenyl, Benzodioxan, aphthalene

Intranasal mRNA Delivery via Customized RNA-Polyplex Nanoparticles Enhancing Gene Expression through Photochemical Mechanisms.

Achieving effective mRNA expression in vivo requires careful selection of an appropriate delivery vehicle and route of administration. Among the various routes of administration, intranasal administration has received considerable attention due to its ability to induce potent immune responses. In this context, we designed a specialized cationic polymer tailored for delivery of mRNA into the nasal cavity. These polymers are designed with varying degrees of substitution in different amine groups to allow for identification of the most suitable amine moiety for effective mRNA delivery. We also incorporated a photosensitizer within the polymer structure that can trigger the generation of reactive oxygen species when exposed to light. The synthesized cationic polymer is complexed with anionic mRNA to form a polyplex. Illuminating these polyplexes with laser light enhances their escape from intracellular endosomes, stimulating mRNA translocation into the cytoplasm, followed by increased mRNA expression at the cellular level. Through intranasal administration to C57BL/6 mice, it was confirmed that these photoactive polyplexes effectively induce mRNA expression and activate immune responses in vivo using photochemical effects. This innovative design of a photoactivated cationic polymer presents a promising and reliable strategy to achieve efficient intranasal mRNA delivery. This approach has potential applications in the development of mRNA-based vaccines for both prophylactic and therapeutic purposes.

Synthesis of polyolefin elastomers from amine-imine nickel-catalyzed ethylene polymerization

The catalytic synthesis of polyolefin elastomers by using ethylene as a sole feedstock is fascinating, while currently reported chain walking catalysts are only limited to α-diimine type. In this contribution, we developed alternative amine-imine nickel catalysts for ethylene polymerization to prepare polyolefin elastomers. The cooperative effect of steric hindrance between the less bulky amine moiety and the bulky imine moiety significantly enhanced the performance of amine-imine nickel-catalyzed ethylene polymerization. The amine-imine nickel catalysts also showed excellent controlled behavior for ethylene polymerization, and living ethylene polymerization was also realized to generate narrowly distributed polyethylenes. The microstructure of the resultant polyethylenes could be tuned by catalyst structure, reaction temperature, and ethylene pressure. The polyethylenes produced by Ni2 with the cyclic amine have higher long-chain branching contents, therefore showing better elastic properties. The strain-at-break value of 888.0 % and the strain recovery value of > 79.0 % are super to most values of polyolefin elastomers generated from α-diimine nickel catalysts.

Bio-based polyester-polyurethane foams: synthesis and degradability by Aspergillus niger and Aspergillus clavatus.

In this article, the degradability by Aspergillus niger and Aspergillus clavatus of three bio-based polyurethane (PU) foams is compared to previous degradability studies involving a Pseudomonas sp. bacterium and similar initial materials (Spontón et al. in Int. Biodet. Biodeg. 85:85-94, 2013, https://doi.org/10.1016/j.ibiod.2013.05.019 ). First, three new polyester-polyurethane foams were prepared from mixtures of castor oil (CO), maleated castor oil (MACO), toluene diisocyanate (TDI), and water. Then, their degradation tests were carried out in an aqueous medium, and employing the two mentioned fungi, after their isolation from the environment. From the degradation tests, the following was observed: (a) the insoluble (and slightly collapsed) foams exhibited free hydroxyl, carboxyl, and amine moieties; and (b) the water soluble (and low molar mass) compounds contained amines, carboxylic acids, and glycerol. The most degraded foam contained the highest amount of MACO, and therefore the highest concentration of hydrolytic bonds. A basic biodegradation mechanism was proposed that involves hydrolysis and oxidation reactions.

Biofilm heterogeneity-adaptive photoredox catalysis enables red light-triggered nitric oxide release for combating drug-resistant infections

The formation of biofilms is closely associated with persistent and chronic infections, and physiological heterogeneity such as pH and oxygen gradients renders biofilms highly resistant to conventional antibiotics. To date, effectively treating biofilm infections remains a significant challenge. Herein, we report the fabrication of micellar nanoparticles adapted to heterogeneous biofilm microenvironments, enabling nitric oxide (NO) release through two distinct photoredox catalysis mechanisms. The key design feature involves the use of tertiary amine (TA) moieties, which function as sacrificial agents to avoid the quenching of photocatalysts under normoxic and neutral pH conditions and proton acceptors at acidic pH to allow deep biofilm penetration. This biofilm-adaptive NO-releasing platform shows excellent antibiofilm activity against ciprofloxacin-resistant Pseudomonas aeruginosa (CRPA) biofilms both in vitro and in a mouse skin infection model, providing a strategy for combating biofilm heterogeneity and biofilm-related infections.

Identification of the Photoreactive Species of Protonated N-Nitrosopiperidine in Acid Medium: A CASPT2 and DFT Study.

In this work, we have studied the initial reaction step after photoexcitation of protonated N-nitrosopiperidine both in the gas and condensed phases. To achieve this end, we have applied the CASPT2 and MP2 wave function methods and the density functional theory approach. It is found that the site of protonation of N-nitrosopiperidine in acid medium depends on the solvent: protonation occurs at the oxygen atom in protic solvents, while in aprotic solvents, the proton is bonded at the N-atom of the amine moiety. Furthermore, protonation at such an N-atom is the unique protonated species that absorbs in the visible range and directly dissociates into aminium radical cation and nitric oxide.

An integrative analytical approach designed for feasible tranexamic acid assay using o-phthalaldehyde as a fluorogenic probe: applications to tablets, ampoules, and urine.

Antifibrinolytic tranexamic acid (TRX) suppresses plasminogen activation to plasmin in a competitive way. TRX is approved for the management of heavy menstrual periods, hereditary angioedema, hemophilia, postpartum hemorrhage, surgery, tooth extraction, and severe blood loss after acute trauma. Here, the practical use of an isoindole derivative was established for a novel, easy-to-use, and affordable TRX assay. In the presence of a molecule containing a sulfhydryl group (2-mercaptoethanol) 0.02% v/v, the primary amine moiety in TRX allows its combination with o-phthalaldehyde to produce a luminous product. Excitation (338.8nm) and emission (433.9nm) wavelengths were used to monitor the isoindole fluorophore yield, and each operational variable was carefully examined and adjusted. The calibration graph was constructed with fluorescence intensity versus TRX concentration, excellent linearity was observed at concentrations between 40 and 950 ng/ml, and limit of detection and limit of quantitation were 41.3 and 13.6ng/ml, respectively. The International Council for Harmonisation of Technical Requirements for Pharmaceuticals for Human Use guidelines were used to validate the method. The developed method for TRX assay in various dosage forms and urine was successfully implemented and was shown to be an effective, simple, and quick replacement for the TRX assay in clinical trials and quality control.

Roles of Fatty Acid Chain Length and Enzyme-Oriented Drug Controlled Release from pH-Triggering Self-Assembled Fatty Acid Conjugated Quetiapine Nanosuspensions.

Quetiapine (QTP) is a first-line antipsychotic drug, but its therapeutic druggability and patient adherence were limited due to high oral dose strength, low bioavailability and physicochemical/biopharmaceutical issues. To investigate the roles of fatty acid chain length and enzyme-oriented QTP controlled release from pH-triggering self-assembled fatty acid conjugated QTP nanosuspensions (NSPs). QTP was conjugated with different chain length fatty acids (C10-decanoic acid, C14-myristic acid, C18-stearic acid) to obtain QTP-fatty acid conjugates (QFCs: QD, QM, QS) by exploiting 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide/4-dimethylaminopyridine (EDC/DMAP) conjugation chemistry. Then, the solubility, partitioning coefficient (log P), cell viability and cleavage kinetics of QFCs were evaluated. The pH-triggering self-assembled behaviors of QFCs to form QTP-fatty acid NSPs (QDN, QMN, QSN) by varying pH, QFC concentration and proton-to-QTP ratios were characterized. The morphological images, critical micelle concentration (CMC), physicochemical properties and enzyme-oriented QTP controlled release of NSPs were examined. Three QFCs were synthesized with different chain length fatty acids from QTP after desalting fumarate from QTP fumarate. The pH, QFC concentration and proton-to-quetiapine molar ratio could influence physicochemical properties and nanonization behaviors of QFCs. All three QFCs showed no effect on the viability of myoblast cells. The pH-triggering self-assembly of amphiphilic QFCs to form nanoparticles (NPs) occurred as the amine moiety of QTP was readily ionized in a strongly acidic environment (pH 1.2). Interestingly, the longer the fatty acid chain length, the lower water solubility, the higher log P (lipophilicity) and the smaller NP particle size were observed. The conversion rate of QFCs to liberate QTP by esterase in human plasma and liver S9 fractions was also inversely proportional to the fatty acid carbon chain length. Interestingly, the freeze-dried QMN showed the esterase-oriented controlled release of QTP over one month, unlike the initial burst release of QDN or the slowly delayed release pattern of QSN. A new pH-triggering self-assembled nanonization platform was developed using different chain length fatty acid conjugated QTP in low pH environment. By varying fatty acid chain length, the enzyme-oriented QTP controlled release dosage form was challenged to enhance the therapeutic effectiveness of QTP.

Exploring the stereochemistry of In(III)-A3B-type porphyrins axially ligated with p-PDA: synthesis, electronic properties and DFT calculations

In(III)-A3B-type porphyrins containing para-phenylenediamine (p-PDA) as an axial moiety have been efficiently synthesized and characterized spectroscopically to procure the structures of the synthesized complexes. The axial coordination of the amine moiety with In(III) porphyrins brings about a modest shift in the 1H NMR signals and the electronic absorptions in CH3OH, CH3COCH3, CHCl3, and CH3COOC2H5 reflect the hyperchromicity of p-PDA-In(III) porphyrins in comparison to non-ligated metal chelates. All the synthesized macrocyclic porphyrins have negative solvatochromism with the blue shift in the electronic absorption spectra in more polar solvents like CH3OH than those in the less polar CHCl3 as solvent. The photoluminescence spectra show maximum excitonic peaks at 623, 620, and 615 nm for p-phenylenediamine-In(III)-5,10,15-trikis(p-methylphenyl)-20-(p-nitrophenyl)porphyrin [p-PDA-In-tPP1], p-phenylenediamine-In(III)-5,10,15-trikis(p-methoxyphenyl)-20-(p-nitrophenyl)porphyrin [p-PDA-In-tPP2] and p-phenylenediamine-In(III)-5,10,15-trikis(p-dimethylaminophenyl)-20-(p-nitrophenyl)porphyrin [p-PDA-In-tPP3], respectively, which confirmed that the In(III) porphyrins are considered to be sitting atop (SAT) or out of the plane (OOP) type complexes. Further, the stability of the complexes was determined through thermogravimetric analysis, and the structural evolutions through different phases of the synthesized porphyrins were deduced from the powder X-ray diffraction. To get more insight into the molecular structures and their complexes, we carried out the quantum mechanical calculations using DFT-based dispersion which showed that from OH− to p-PDA substitution, the BDE energies drop considerably.

Rapid fabrication of composite membranes based on conjugated microporous polymers: Microstructural design for performance optimization

Composite membranes based on conjugated microporous polymer (CMPs) with permanent porosity and high tolerance to harsh environments have been considered as one of the most promising separation methods to treat wastewater. Nevertheless, using simple and low-cost methods to accomplish the rapid fabrication of CMPs-based membranes with excellent performance is challenging. Herein, unidirectional diffusion synthesis in diffusion cells of different inner diameters achieved the rapid fabrication and adjustable size of three CMPs-based composite membranes (i.e., TpMa-H, TpMa-CH3 and TpMa-Cl). Among them, TpMa-CH3 or TpMa-Cl was obtained by replacing -H of Carbon 4 in the amine moieties of TpMa-H with -CH3 or -Cl groups. This microstructural design enhanced the rejection rates of TpMa-CH3 and TpMa-Cl to model waste molecules compared with TpMa-H. In addition, the composite membranes had strong hydrolytic resistance, thermal stability and acid-base resistance. Interestingly, TpMa-CH3 showed better rejection to positively charged methyl violet (Mw.358) than that to negatively charged sodium cresol (Mw.404), probably due to the electrostatic adsorption of bigger positive portion of methyl violet on the membrane surface and resultant bridging effect. Such electrostatic adsorption and the adjustable microstructures significantly varied the repellence of CMPs-based membranes to different charged molecules. This work provides a beneficial idea to optimize the separation performance of the CMPs-based membrane.

Ultraviolet Light Responsive N-Nitroso Polymers for Antibacterial Nitric Oxide Delivery.

This study investigates the incorporation of active secondary amine moieties into the polymer backbone by co-polymerizing 2,4,6-tris(chloromethyl)-mesitylene with three diamines, namely 1,4-diaminobutane, m-phenylenediamine, and p-phenylenediamine. This process results in the stabilization of the amine moieties and the subsequently introduced nitroso groups. Charging bioactive nitric oxide (NO) into the polymers is accomplished by converting the amine moieties into N-nitroso groups. The ability of the polymers to store and release NO depends on their structures, particularly the amount of incorporated active secondary amines. With grafting photosensitive N-nitroso groups into the polymers, the derived NO@polymers exhibit photoresponsivity. NO release is completely regulated by adjusting UV light irradiation. These resulting polymeric NO donors demonstrate remarkable bactericidal and bacteriostatic activity, effectively eradicating E. coli bacteria and inhibiting their growth. The findings from this study hold promising implications for combining NO delivery with phototherapy in various medical applications.

Structure, interaction with biomolecules, and cytotoxicity of copper (II) complexes chelating some Schiff base ligands

Cancer remains one of the most common diseases worldwide in terms of deaths and claims many lives every day. Transition metal complexes are candidates in the development of anticancer drugs, with cisplatin being used in chemotherapy worldwide. Copper, an endogenous metal, is known for its pronounced redox potential and nucleophilicity, especially when bound to biological molecules. Cu (II) complexes were synthesized containing ethane‐1,2‐diamine as amine moiety and pentane‐2,4‐dione and/or 1‐phenylbutane‐1,3‐dione, pentane‐2,4‐dione and/or 1,1,1‐trifluoropentane‐2,4‐dione or 1,1,1‐trifluoropentane‐2,4‐dione and/or 1‐phenylbutane‐1,3‐dione as β‐diketone moiety. Standard methods were used to confirm the structure of complexes 1–6. X‐ray crystal structure analysis characterized complex 1 containing the ligand ethane‐1,2‐diamine and pentane‐2,4‐dione. The interactions of complexes 1–6 with calf thymus DNA (ct‐DNA) were followed by electronic absorption and fluorescence spectroscopy methods and by viscosity measurements. In contrast, interaction with Salmon Sperm DNA was investigated using the electrophoretic mobility shift assay. The results indicate a moderate affinity of complexes 1–6 for binding to DNA. Gel electrophoresis also shows that the studied complexes have a concentration‐dependent interaction with DNA. Spectroscopic fluorescence techniques were used to monitor the affinity of the complexes for bovine serum albumin (BSA). Complexes 1–6 showed satisfactory binding ability for BSA. Cytotoxicity analyses were performed on the human colorectal carcinoma HCT‐116 and healthy lung fibroblast MRC‐5 cell lines, showing that complex 5 exhibited selectivity between cancer and normal cells, which is critical for drug development.

Betainization of Polydopamine/Polyethylenimine Coating for Universal Zwitterionization.

Biofoulants can adhere to multiple surfaces, degrading the performance of medical devices and industrial facilities and/or causing nosocomial infection. The surface immobilization of zwitterionic materials can prevent the initial attachment of the foulants but lacks extensive implementation. Herein, we propose a facile, universal, two-step surface modification strategy to improve fouling resistance. In the first step, the substrates were immersed in a codeposition solution containing dopamine and branched polyethylenimine (PEI) to form a "primer" layer (PDA/PEI). In the second step, the primer layers were treated with 1,3-propane sultone to betainize primary/secondary/tertiary amine moieties of PEI, generating zwitterions on substrates. After betainization, PS-grafted PDA/PEI (PDA/PEI/S) via a ring-opening alkylation reaction manifested changes in wettability. X-ray photoelectron spectroscopy revealed the presence of zwitterionic moieties on the PDA/PEI/S surfaces. Further investigations using ellipsometry and atomic force microscopy were conducted to scrutinize the relation among the PEI content, film thickness, primer stability, and betainization. As a result, zwitterion-decorated substrates prepared under optimal conditions can exhibit high resistance against bacterial fouling, achieving a 98.5% reduction in bacterial attachment. In addition, the method shows a substrate-independent property, capable of successfully applying it on organic and inorganic substrates. Finally, the newly developed approach shows excellent biocompatibility, displaying no significant difference compared with blank control samples. Overall, we envision that the facile surface modification strategy can further promote the preparation of zwitterion-decorated materials in the future.

Thermodynamic Overview of Bioconjugation Reactions Pertinent to Lysine and Cysteine Peptide and Protein Residues

Bioconjugation reactions are critical to the modification of peptides and proteins, permitting the introduction of biophysical probes onto proteins as well as drugs for use in antibody-targeted medicines. A diverse set of chemical reagents can be employed in these circumstances to covalently label protein side chains, such as the amine moiety in the side chain of lysine and the thiol functionality in cysteine residues, two of the more frequently employed sites for modification. To provide researchers with a thermodynamic survey of the reaction of these residues with frequently employed chemical modification reagents as well as reactive cellular intermediates also known to modify proteins non-enzymatically, a theoretical investigation of the overall thermodynamics of models of these reactions was undertaken at the T1 and G3(MP2) thermochemical recipe levels (gas phase), the M06-2X/6-311+G(2df,2p)/B3LYP/6-31G(d) (gas and water phase), and the M06-2X/cc-PVTZ(-f)++ density functional levels of theory (water phase). Discussions of the relationship between the reagent structure and the overall thermodynamics of amine or thiol modification are presented. Of additional interest are the observations that routine cellular intermediates such as certain thioesters, acyl phosphates, and acetyl-L-carnitine can contribute to non-enzymatic protein modifications. These reactions and representative click chemistry reactions were also investigated. The computational survey presented herein (>320 reaction computations were undertaken) should serve as a valuable resource for researchers undertaking protein bioconjugation. A concluding section addresses the ability of computation to provide predictions as to the potential for protein modification by new chemical entities, with a cautionary note on protein modification side reactions that may occur when employing synthetic substrates to measure enzyme kinetic activities.

Site-Selective Modification of Secondary Amine Moieties on Native Peptides, Proteins, and Natural Products with Ynones.

Site-selective modification of biologically relevant secondary amines in peptides, proteins, and natural products has been challenging due to the similar reactivity between primary and secondary amines. Even for the secondary amines, their reactivities are significantly influenced by their structures and environment. Herein, we report a ynone Michael bioconjugation method for selective modification of secondary amines in unprotected peptides and proteins and complex natural products. We show that fine tuning the electronic effect of the ynones enables controlling the Michael acceptor reactivity for the selective reaction with the structurally different secondary amines in densely functionalized complex structures and complicated biological environment.

Synthesis, characterization and crystal structure of methyl 2-(2-oxo-2H-chromen-4-yl-amino)-benzoate.

Methyl 2-(2-oxo-2H-chromen-4-yl-amino)-benzoate, C17H13NO4 (1), was pre-pared by condensation between 4-hy-droxy-coumarin and methyl 2-amino-benzoate. It crystallizes in the ortho-rhom-bic space group Pca21 at 300 K. The mol-ecule of compound 1 consists of the 2H-chromen-2-one part connected by an amine moiety (-NH-) to the methyl benzoate ring. The supra-molecular array is formed by hydrogen bonds between the aromatic ring and the O atoms of the lactone and ester portions. The structural details match the spectroscopic data acquired from NMR and IR spectroscopy.

H2S/CO2 separation using sterically hindered amine membranes

With the growing interest in carbon capture from syngas and natural gas, H2S/CO2 separation is gradually becoming important in the gas processing and carbon capture industries. This work describes the development of amine-based facilitated transport membranes (FTMs) suitable for syngas desulfurization. Six amino acid salt carriers with varying steric hindrance were synthesized and used to fabricate FTMs. Their H2S/CO2 separation performances were evaluated at 107 °C and 7 bar feed pressure, using a dry feed composition of 1.5% H2S and 98.5% CO2. H2S/CO2 selectivity improved significantly as amine steric hindrance was increased. While mildly hindered amines showed low H2S/CO2 selectivities of around 5, sterically hindered and tertiary amines showed substantially improved separation performance, with selectivities in the range of 10–20. A highly hindered carrier containing the di-tert-butyl amine moiety showed the highest selectivity of 19.6, along with an H2S permeance of 560 GPU. The di-tert-butyl amine-based FTM was used to study the effect of temperature and feed H2S content on H2S/CO2 separation performance. The performances of the newly devised FTMs exceed the H2S/CO2 upper bound, and the learnings shed light on the design of amine carriers for acid gas separations.

Enhanced PFAS adsorption with N-doped porous carbon beads from oil-sand asphaltene

Highly porous carbon beads with radially aligned macrochannels were synthesized from asphaltene for wastewater treatment and water filtration purposes. The unique porous structure of these beads facilitates efficient solute diffusion and maximizes liquid accommodation capacity, thanks to the well-ordered inwardly aligned macrovoids. Additionally, N-doping was employed to enhance the beads' adsorption properties, particularly for organic and inorganic solvents. Surface characterization data revealed that N2 modification introduced new surface functionalities, likely pyridine, and amine moieties, which actively participate in the adsorption process of polyfluoroalkyl and perfluoroalkyl substances (PFAS). Although the highest adsorbed amount of up to 74 μmol g−1 was observed for the unmodified materials, it is noteworthy that achieving equilibrium required an extensive period, exceeding 300 h. Interestingly, adsorption onto N2-modified asphaltene carbon beads exhibited higher efficiency for shorter-chain PFAS, with perfluorobutanoic acid adsorbing at 66.41 μmol g−1 and perfluorooctanoic acid reaching up to 7.67 μmol g−1. Overall, the maximum adsorption capacity of all asphaltene carbon beads followed the order PFHxA < PFOA < PFBA, indicating that the length of the carbon chain in PFAS is not the sole determining factor for adsorption. This observation suggests that the modification of asphaltene carbon beads and the introduction of N2 in the form of amino groups provide additional sites for hydrogen bond formation, influencing the adsorption process. The presented results highlight the enhanced efficiency of PFAS removal achieved by utilizing sustainable materials and methods in wastewater treatment.

Applicability of fluorescamine as a fluorogenic reagent for highly sensitive fluorimetric analysis of the tyrosine kinase inhibitor (avapritinib) in pharmaceuticals and biological samples.

Avapritinib (AVP) was the first precision drug to be approved by the US Food and Drug Administration (FDA) in 2020 for patients suffering from metastatic gastrointestinal stromal tumors (GISTs) and progressive systemic mastocytosis. The analysis of AVP in pharmaceutical tablets and human plasma was then carried out using a fast, efficient, sensitive, and simple fluorimetric method using a fluorescamine reagent. The procedure is based on the interaction between fluorescamine as a fluorogenic reagent and the primary aliphatic amine moiety in AVP using borate buffer solution at pH8.8. The produced fluorescence was measured at 465 nm (Excitation at 395 nm). The calibration graph's linearity range was discovered to be 45.00-500.0ng mL-1 . Utilizing the International Council for Harmonization (ICH) and US-FDA recommendations, the research technique was validated and bioanalytically validated. The proposed approach was effectively employed for determining the stated pharmaceuticals in plasma with a high percentage of recovery ranging from 96.87 to 98.09 and pharmaceutical formulations with a percentage of recovery equal to 102.11% ± 1.05%. In addition, the study was extended to a pharmacokinetic study of AVP with 20 human volunteers as a step for AVP management in therapeutic cancer centers.