Articles in "Chemistry"

Summary: Background/Objectives: Genetic polymorphisms in the BRCA2 gene have been implicated in breast cancer susceptibility. While numerous studies have investigated this polymorphism, its precise role in breast cancer development remains unclear. Furthermore, to the best of our knowledge, no related studies have been conducted in Azerbaijan. The aim of this study was to determine the distribution of the BRCA2 Met1915Thr polymorphism (rs4987117) in the Azerbaijani population and to evaluate its potential association with breast cancer risk. Methods: A total of 144 breast cancer patients and 152 healthy controls were recruited from the Oncology Clinic of Azerbaijan Medical University between 2021 and 2024. The Met1915Thr polymorphism was genotyped using PCR-RFLP and visualized on a 2% agarose gel. Results: A statistically significant association with increased breast cancer susceptibility was observed for the heterozygous Met/Thr genotype (OR = 1.83, 95%CI = 1.08–3.11, p = 0.02), the Thr allele (OR = 1.57, 95%CI = 1.12–2.20, p = 0.008), and under the dominant inheritance model (OR = 1.83, 95%CI = 1.15–2.90, p = 0.01). Notably, this association was more evident among individuals aged over 58 years, in whom the Met/Thr genotype conferred a significantly elevated risk (OR = 2.35, 95%CI = 1.17–4.73, p = 0.02). Conclusions: The BRCA2 Met1915Thr polymorphism is associated with an increased risk of breast cancer in the Azerbaijani population. These findings suggest a potential role of this polymorphism in breast cancer susceptibility and highlight the need for further studies in larger cohorts to validate these associations.

Summary: This study provides the first-reported evidence that aliphatic structured surfactant, N-octylaminopropan-2-ol (OSI), is a novel and effective inhibitor of the aggregation of acidic, island-structured crude oil asphaltenes (AZO). The molecular mechanisms of OSI’s effective dispersion were elucidated using a combination of advanced spectroscopic techniques and Density Functional Theory (DFT) calculations. Fourier Transform Infrared Spectroscopy (FT-IR) and Nuclear Magnetic Resonance (NMR) analyses revealed strong interactions between OSI and A-ZO, including hydrogen bonding and acid-base interactions, which prevent asphaltene precipitation in crude oil. Differential Thermal Analysis (DTA) confirmed the chemisorption of 12.5 % OSI onto A-ZO. Dynamic Light Scattering (DLS) measurements showed a significant reduction in the average nanosize of A-ZO in hexane, decreasing from 583 nm to 76 nm after treatment with OSI. Scanning Electron Microscopy (SEM) images of the A-ZO and OSI mixture revealed the filling of deep grooves and cracks on the rough surface of the asphaltene agglomerates, demonstrating the resin-like dispersion effect of OSI. DFT simulation reveals a binding energy of ???? 28.2 kcal/mol for A-ZO and OSI complex formation. Noncovalent interaction (NCI) analysis shows that van der Waals interactions occur [sign(λ2)ρ ≈ ???? 0.015 to +0.005 au] in a large region between the OSI saturated tail and the A-ZO polycyclic aromatic fragment, which explains experimentally observed well-disperssed state of the hexane + A-ZO mixture after the addition a certain amount of OSI. The detailed, data-driven analysis offers unique molecular-level insights into asphaltene stabilization, presenting OSI as a significant alternative to traditional inhibitors for the oil industry.

Summary: Cocogem surfactants are synthesized based on the neutralization reaction of higher monocarboxylic acids (octanoic acid, nonanoic acid, decanoic acid, undecanoic acid, dodecanoic acid, tetradecanoic acid, hexadecanoic acid, heptadecanoic acid, octadecanoic acid) and 2:1 mol of N,N’-bis(propyl-2-ol)ethylenedia mine). Krafft temperatures of these surfactants and colloidal chemical properties of their aqueous solutions were determined by using tensiometric and conductometric measurements. Surface activity parameters of cocogem surfactants, critical micelle concentration (CMC), counter-ion binding degree (b), the surface tension reduction effectiveness (pCMC), excess concentration of surface (Cmax), as well as area per molecule at the interface (Amin), Gibbs free energy (DGad and DGmic) values of adsorption and micellar formation processes are calculated. The size of the aggregates formed by anionic cocogem surfactants in an aqueous solution was determined by the DLS method. It was defined that cocogem surfactants have antibacterial properties against SRB, which is considered to be the most dangerous for the oil industry.

Summary: In this study, the complexes synthesized by reactions of oleic acid separately with ethylenediamine and triethylenetetramine were reacted with different moles of propylene oxide to form propoxylated compounds. The obtained propoxylated compounds were characterized by a number of physico-chemical methods. The physical properties of the synthesized surfactants including interfacial tension and critical micelle concentration were determined. From thesemeasurements, themaximum surface excess concentration and the minimum area per molecule at the water solution/ kerosene interface and the standard thermodynamic parameters of adsorption and micellization were calculated. Petroleum-collecting and dispersing properties of the synthesized propoxylated complexes in diluted and undiluted form inwaters of varying salinity have been studied. FTIR spectra, C13 and H1-NMR spectra confirm these complex structures.

Summary: Novel symmetric and dissymmetric pseudo-gemini surfactants are synthesized using ethylpiperazine, propylene oxide and six different fatty acids (capric, lauric, myristic, palmitic, stearic, oleic) as starting materials. The synthesis follows a simple pathway excluding heating or catalyst. Important surface activity properties including critical micelle concentration (CMC), surface tension at CMC (γCMC), surface pressure at CMC (πCMC), negative logarithm of concentration to achieve 20 mN/ m reduction in surface tension (pC20), minimum area at interface (Amin) and maximum surface excess concentration (Γmax) are obtained through surface tension and electrolytic conductivity measurements. Antimicrobial properties of the synthesized amphiphiles are evaluated using disk diffusion method and are compared to those of standard antibiotic agents. Particle size distribution patterns are obtained using dynamic light scattering (DLS). This work investigates the effect of dissymmetry on various surface activity and antimicrobial properties. Dissymmetric pseudo-gemini amphiphiles have a few times higher CMC compared to analogous symmetric surfactants. However, better antimicrobial properties are observed when there is some dissymmetry between hydrophobic groups.

Summary: In this study, a detailed assessment of interactional conduct between different head-groups of cationic surfactants and different monomer fragments of anionic polyelectrolyte of aqueous media is reported. Tensiometry, conductometry, viscosimetry, dynamic light scattering have been employed to get insight into interactions among cationic surfactant and polyelectrolyte in interfacial region critical aggregation and micellization concentration, surface excess concentration, surface pressure at interface, minimum area occupied with the aid of one molecule of cationic surfactant at air-solvent interface, adsorption efficiency, surface tension at critical micelle concentration and the positive degree of counterion binding had been calculated. Thermodynamic parameters, i.e., standard Gibbs free energy of micellization and adsorption processes had been evaluated. Polyelectrolyte-surfactant interaction used to be studied in dependence on nature of head-group of cationic surfactant and polyelectrolyte chain and their influence on colloidalchemical parameters of polyelectrolyte-surfactant complexes has been compared. Petrocollecting ability of these complexes in the waters of various mineralization degree was investigated.

Summary: New cationic ionic liquid surfactants (ILS) based on (C9-C10, C12 and C14) alkyl bromides and N-2- hydroxypropyl piperidine have been synthesized. Colloidal parameters of aqueous solutions of the obtained ILSs were studied by surface tension and dynamic light scattering methods. Specific electrical conductivity was measured by the conductometric method. Depending on the alkyl chain length, critical micelle concentration (CMC), maximum adsorption (Umax), the minimum cross-sectional area of the surfactant polar group (Amin), adsorption efficiency (pC20), surface pressure (pCMC), degree of counterion binding (b), changes of the Gibbs free energy of micellization and adsorption (DGmic and DGad) were studied. The ILSs antimicrobial properties were tested on various bacteria and fungi.

Summary: Two new classes of gemini cationic surfactants— hexanediyl-1,6-bis[(isopropylol) alkylammonium] dibromide {in the abbreviation form: CnC6Cn[iPr-OH] and CnC6Cn[iPr- OH]2; alkyl: CnH2n + 1 with n = 9, 10, 12 and 14}—have been synthesized by interaction of alkyl bromides with N,N0-di- (isopropylol)-1,6-diaminohexane and N,N,N0,N0-tetra-(isopropylol)- 1,6-diaminohexane. The surface tension, electrical conductivity, and dynamic light scattering (DLS) techniques were used to investigate the aggregation properties of the gemini cationic surfactants in aqueous solution. The formation of critical aggregates at two concentrations in an aqueous solution from obtained gemini cationic surfactants were determined via the tensiometric method. Thus, these gemini cationic surfactants start to form aggregates at concentrations well below their critical micelle concentrations (CMC). The surface properties and the binding degree (β) of the opposite ion were tested against the length of the surfactant hydrocarbon chain and the number of the isopropylol groups in the head group. By applying the DLS technique, it was explored that how the number of isopropylol groups in gemini cationic surfactants with C12H25 chain affects the sizes of micelles at concentrations greater than CMC. It was discovered that the obtained gemini cationic surfactants have a biocidal character.

Summary: Different head-group containing ionic-liquid cationic surfactants (ILCS) are synthesized by the reaction of 1-bromododecane and various alkylethanolamines ([mono(2-hydroxyethyl)amine, methyldiethanolamine, di(2- hydroxyethyl)amine, tris(2-hydroxyethyl)amine, 2-(methylamino)ethanol, N-2-(dimethylamino)ethanol, 2- (dimethylamino)ethanol]), which hold 2-hydroxyethyl group functionality. By tensiometric and conductometric measurements, surface parameters of the synthesized ILCSs are investigated. Variation of the colloid-chemical parameters with a change in the head group (e.g., replacing methyl-with ethyl- and 2-hydroxyethyl fragments) is recorded. The synthesized ILCSs antimicrobial properties are studied. Microbial assay analysis shows that C12DEA is the most effective biocide relative to other ILCS. New polyelectrolyte-surfactant complexes are also synthesized via stepwise procedure: Acrylic acid and potassium acrylate are polymerized and obtained polymer is propoxylated, then exploiting di(2-hydroxyethyl)amine and tris(2-hydroxyethyl)amine, the synthesized propoxylated acrylic polymers are neutralized. Our studies reveal that the synthesized polyacrylate surfactant complexes are promising substances for oil recovery.

Summary: Ionic liquid (IL) surfactants were prepared from 1-bromododecane and ethanolamines (2-dimethyl- and 2-diethylethanolamines) in an equimolar ratio to reveal how their oil-collecting and dispersing ability is infl uenced by the structure of the alkyl fragment. The surface activity of the substances synthesized was studied tensiometrically, and the electrical conductivity, conductometrically. The eff ect exerted on the colloid-chemical parameters of the surfactants by the replacement of the methyl fragment in the head group by the ethyl fragment is described. The relative oil-collecting and oil-dispersing ability of these substances was evaluated under laboratory conditions by the example of a thin oil fi lm on the surface of waters with diff erent levels of mineralization.