Molecular characterization of ß-thalassemia in Azerbaijan

PubMedID: 1483699We have analyzed the ß-thalassemia mutations in 99 chromosomes of 49 adults with ß-thalassemia major and of one with Hb S-ß-thalassemia, who are regular patients at a large hematology clinic in Bakü, Azerbaijan. A total of 20 different mutants were identified; three [frameshift at codon 8 (-AA); IVS-II-I (G›A); IVS-I-110 (G›A)] were present in about two-thirds of all chromosomes. Most alleles are the same as found in Mediterranean populations; a few have an Asian origin or come from Kurdistan, Lebanon, Saudi Arabia, or a black population. One mutant [frameshift at codons 82/ 83 (-G)] might be specific for the Azerbaijanian population. Nearly all patients were transfused, which made quantitation of Hb F impossible; highG? values were present in the Hb F of those patients whose ß-thalassemia chromosome carried the C › T mutation at position - 158 in the promoter of the G?-globin gene. © 1992 Springer-Verlag

Counterion-coupled gemini surfactants based on propoxylated hexamethylenediamine and fatty acids: Theory and application

Novel cocogem surfactants are synthesized from N, N′-di-(propane-2-olyl)-1,6-hexanediamine and six different fatty acids (capric, lauric, myristic, palmitic, stearic, oleic). N,N′-di-(propane-2-olyl)-1,6-hexanediamine is the product of the reaction between hexamethylenediamine and propylene oxide in 1:2 mol ratio. Important surface activity parameters, such as critical micelle concentration (CMC), negative logarithm of the concentration required for 20 mN/m reduction in surface tension (pC20), surface pressure (πCMC), surface excess concentration (Γmax) of the synthesized surfactants are determined. Application properties such as foamability, foam stability, and emulsion stability of cocogem surfactants are measured. Absorption and micellization Gibbs energies are calculated. Surfactants having palmitic and stearic tails display quite high foam and emulsion stability. Viscosity measurement data are utilized to explain the high foam persistence and emulsion stability of these surfactants. The cocogem surfactant based on myristic acid is able to show surface tension reduction performance comparable to that of commercial fluorinated surfactants. Computational studies are performed in density functional theory (DFT) B3LYP functional and 6-31G* basis set for optimizing the synthesized surfactant structures and determining their formation free energies. © 2020 Elsevier B.V

New class of cocogem surfactants based on hexamethylenediamine, propylene oxide, and long chain carboxylic acids: Theory and application

Six cocogem surfactants were synthesized from N,N,Nʹ,Nʹ-tetra-(propane-2-olyl)-1,6-hexanediamine and higher monocarboxylic acids: capric, lauric, myristic, palmitic, stearic and oleic. N,N,Nʹ,Nʹ-tetra-(propane-2-olyl)-1,6-hexanediamine was synthesized from hexamethylenediamine and propylene oxide at room temperature, without utilizing any catalyst or solvent. Surface tension, conductivity, foaming ability, foam stability, emulsion stability, viscosity and density measurements were performed on aqueous solutions of all cocogem surfactants. Their surface activity and colloidal-chemical parameters such as critical micelle concentration (CMC), surface pressure at CMC (πCMC), surface tension at CMC (γCMC), surface excess (Γmax), concentration required for 20 mN/m reduction of surface tension (C20), Gibbs energies of adsorption and micellization (ΔGad and ΔGmic) were recorded and variation of these parameters based on hydrophobic chain length and structure was investigated experimentally and computationally. Synthesized surfactants with myristic, palmitic, and stearic tail continued to decrease surface tension even above CMC. The possible reason of this unusual behavior was determined based on computational studies. Surface activity parameters of cocogem surfactant with oleic tail disobeyed the general tendency established by other cocogems with saturated tail group. Palmitic and stearic acid based cocogem surfactants had good foam stability and the reason of this high foam stability was rationalized with high viscosity of their solutions. © 2020 The Korean Society of Industrial and Engineering Chemistr

Aggregation and antimicrobial properties of gemini surfactants with mono- and di-(2-hydroxypropyl)ammonium head-groups: Effect of the spacer length and computational studies

Cationic gemini surfactants, alkanediyl-α,ω-bis[(2-hydroxypropyl)dodecylammonium] dibromide (abbreviated as C12-s-C12[iso-Pr(OH)] and C12-s-C12[iso-Pr(OH)]2, with s = 2, 3, 4 and 5) have been synthesized, and their aggregation properties in aqueous solution have been studied by surface tension, electrical conductivity and dynamic light scattering methods. On the basis of the results of studying aqueous solutions of the synthesized gemini surfactants by tensiometric and conductometric methods, their principal surfactivity parameters, such as the degree of counterion binding (β), critical micelle concentration (CMC), effectiveness of surface tension reduction (πCMC), surface excess concentration (Γmax), area per molecule at the interface (Amin), changes of Gibbs free energies of adsorption (ΔGad) and micellization (ΔGmic) have been calculated. For both classes of these gemini surfactants, a character of the surfactivity parameters change with an elongation of the spacer chain was defined and comparative analysis with other ammonium-type gemini surfactants having different head-groups was performed. Using dynamic light scattering method, regularities of variation of the aggregates sizes were studied depending on the number of 2-hydroxypropyl groups and the spacer chain length was investigated. Meanwhile, it was revealed that the mentioned gemini surfactants possess antimicrobial properties. The mechanism of the epoxide ring opening and salt formation reactions were calculated by using Kohn–Sham DFT with the B3LYP functional. The epoxide ring opening via primary (dodecylamine) and secondary (INT2) amines was determined as exergonic (13.4 and 4.4 kcal/mol) reactions as observed experimentally. © 2020 Elsevier B.V