Effect of curcumin on lateral diffusion of phosphatidylcholines in saturated and unsaturated bilayers

© 2014 American Chemical Society. Curcumin, a dietary polyphenol, is a natural spice with preventive and therapeutic potential for neurodegenerative diseases such as Alzheimer's and Parkinson's diseases. Curcumin possesses a spectrum of antioxidant, anti-inflammatory, anticarcinogenic, and antimutagenic properties. Because of this broad spectrum of pharmacological activity, it has been suggested that, like cholesterol, curcumin exerts its effect on a rather basic biological level, such as on lipid bilayers of biomembranes. The effect of curcumin on translational mobility of lipids in biomembranes has not yet been studied. In this work, we used 1H NMR diffusometry to explore lateral diffusion in planar-oriented bilayers of dimyristoylphosphatidylcholine (DMPC) and dioleoylphosphatidylcholine (DOPC) at curcumin concentrations of up to 40 mol % and in the temperature range of 298-333 K. The presence of curcumin at much lower concentrations (∼7 mol %) leads to a decrease in the lateral diffusion coefficient of DOPC by a factor of 1.3 at lower temperatures and by a factor of 1.14 at higher temperatures. For DMPC, the diffusion coefficient decreases by a factor of 1.5 at lower temperatures and by a factor of 1.2 at higher temperatures. Further increasing the curcumin concentration has no effect. Comparison with cholesterol showed that curcumin and cholesterol influence lateral diffusion of lipids differently. The effect of curcumin is determined by its solubility in lipid bilayers, which is as low as 10 mol % that is much less than that of cholesteroĺs 66 mol %

Effect of curcumin on lateral diffusion of phosphatidylcholines in saturated and unsaturated bilayers

© 2014 American Chemical Society. Curcumin, a dietary polyphenol, is a natural spice with preventive and therapeutic potential for neurodegenerative diseases such as Alzheimer's and Parkinson's diseases. Curcumin possesses a spectrum of antioxidant, anti-inflammatory, anticarcinogenic, and antimutagenic properties. Because of this broad spectrum of pharmacological activity, it has been suggested that, like cholesterol, curcumin exerts its effect on a rather basic biological level, such as on lipid bilayers of biomembranes. The effect of curcumin on translational mobility of lipids in biomembranes has not yet been studied. In this work, we used 1H NMR diffusometry to explore lateral diffusion in planar-oriented bilayers of dimyristoylphosphatidylcholine (DMPC) and dioleoylphosphatidylcholine (DOPC) at curcumin concentrations of up to 40 mol % and in the temperature range of 298-333 K. The presence of curcumin at much lower concentrations (∼7 mol %) leads to a decrease in the lateral diffusion coefficient of DOPC by a factor of 1.3 at lower temperatures and by a factor of 1.14 at higher temperatures. For DMPC, the diffusion coefficient decreases by a factor of 1.5 at lower temperatures and by a factor of 1.2 at higher temperatures. Further increasing the curcumin concentration has no effect. Comparison with cholesterol showed that curcumin and cholesterol influence lateral diffusion of lipids differently. The effect of curcumin is determined by its solubility in lipid bilayers, which is as low as 10 mol % that is much less than that of cholesteroĺs 66 mol %

Effect of curcumin on lateral diffusion in lipid bilayers

© 2016 Mendeleev Communications. Published by ELSEVIER B.V.Lateral diffusion in dimyristoylphosphatidylcholine lipid bilayers decreases in the presence of cholesterol and curcumin, as measured by 1H NMR spectroscopy, but the mechanisms of action of these two compounds are different

Development of high-entropy eutectic alloys for structural applications

The systems AlCoFeNiTi, CoCuFeNiTi, AlCoCrFeNi are considered from the point of view of creating structural alloys with a eutectic structure

Al-Cu-Zr MODIFYING ADDITIONS FOR ALUMINUM ALLOYS

The effect of small additions of zirconium and copper on the grain refinement of the Ak7 alloy and its structural components is considered. Additives were introduced both in the form of an experimental Al-Cu-Zr complex ligature and Al-Cu and Al-Zr binary alloys

Modification of Silumins with Complex Additives of Cu with Zr AND Cu with Ti

The modifying ability of the experimental Al-Cu-Ti, Al-Cu-Zr master alloys on the industrial alloy Al-7%Si-0.45Mg (A396, Ak7h) was evaluated and compared with the commercial Al-Ti-B master alloy. Modification was carried out in a bucket with a melt mass of 60 kg

Влияние температуры на формирование стабильных и метастабильных алюминидных фаз в сплавах системы Al-Zr-Nb

The paper considers formation conditions for stable and metastable aluminides Aln(Zr1-xNbx) obtained in the crystallization of superheated Al—Zr—Nb melts. At the close zirconium content in the alloys of 0.23—0.25 at.%, the niobium content varied from 0.05 to 0.21 at.%. Alloys were prepared in a resistance furnace at 1230 °C in an argon atmosphere in graphite crucibles. Alloys were cast into a bronze mold where the cooling rate was estimated at 200 °C per second. The structural features, distribution pattern, morphology, the composition of the matrix, dendritic cells and aluminides, as well as the structural type of intermetallics in the investigated alloys were studied using scanning electron and optical microscopy, X-ray phase analysis, X-ray diffraction analysis, electron microprobe analysis including inductively coupled plasma atomic emission spectroscopy. It was shown that the growth forms of stable aluminides (D023 structural type) change from the faceted to dendritic one, and primary metastable aluminides (L12 structural type) begin to form during the Al—Zr—Nb melt overheating at 360—365 °C above the liquidus temperature. Only metastable aluminides with both polyhedral and dendritic growth forms are formed in the alloys when overheated by 390 —395 °C and higher. The near-peritectic niobium composition of the Al—Zr—Nb alloy (at the zirconium content more than seven times higher than the peritectic one) are crucial factors in the formation of a large fraction of metastable AlnZr aluminides having a cubic L12 structure. It was shown that, in accordance with isomorphism rules, Nb replaces Zr at equivalent positions of the crystal lattice of aluminides. The intensity of isomorphism of the Al4(Zr0.79Nb0.21) intermetallics formed increases with the increasing melt overheating temperature.Рассмотрены условия формирования стабильных и метастабильных алюминидов Aln(Zr1-x.Nbx), образующихся при кристаллизации перегретых расплавов системы Al— Zr—Nb. При близком содержании циркония в сплавах (0,23—0,25 ат.%) содержание ниобия изменялось от 0,05 до 0,21 ат.%. Сплавы готовили в печи сопротивления при температуре 1230 °С в атмосфере аргона в графитовых тиглях. Разливку сплавов проводили в бронзовую изложницу, скорость охлаждения в которой составляла примерно 200 град/с. Электронной сканирующей и оптической микроскопией, а также методами рентгенофазового, рентгеноструктурного и микрорентгеноспектрального анализов, в том числе атомно-эмиссионной спектрометрией с индуктивно связанной плазмой, изучены структурные особенности, характер распределения, морфология, состав матрицы, дендритных ячеек и алюминидов, а также структурный тип интерметаллидов в исследуемых сплавах. Показано, что при перегреве расплавов системы Al—Zr—Nb над температурой ликвидуса на 360—365 °C происходит смена форм роста стабильных алюминидов структурного типа D023 от гранной к дендритной и начинают формироваться метастабильные алюминидные фазы с кубической решеткой структурного типа L12. При перегреве на 390—395 °C и выше в сплавах образуются только метастабильные алюминиды, имеющие как полиэдрические, так и дендритные формы роста. Околоперитектический (по ниобию) состав сплава Al—Zr—Nb (при содержании циркония, более чем в 7 раз превышающем перитектическое) определяет формирование в нем большой доли метастабильных алюминидов AlnZr с кубической решеткой L12. Показано, что в соответствии с правилами изоморфизма Nb замещает Zr в эквивалентных позициях кристаллической решетки алюминидов. С увеличением температуры перегрева расплавов интенсивность изоморфизма в формирующихся интерметаллидах Al4(Zr0,79Nb0,21 ) возрастает

FORMATION OF Al-Y ALLOYS OF HYPOEUTECTIC COMPOSITION WITH SMALL ADDITIONS OF Sc AND Zr

The study was made of the effect of small additions of transitional additives and heat treatment on the structure and service properties of Al-Y hypoeutectic alloys

ANTIFRICTION COVERING OFCu-Fe-Al-Pb FOR SLIDING BEARINGS

The samples of connecting rod bushes of world’s manufacturers were analyzed. The new composition of antifriction coating on a copper basis is presented.Исследование выполнено за счет гранта Российского Научного Фонда (проект РНФ №15-13-00029)

Effect of curcumin on lateral diffusion of phosphatidylcholines in saturated and unsaturated bilayers

© 2014 American Chemical Society. Curcumin, a dietary polyphenol, is a natural spice with preventive and therapeutic potential for neurodegenerative diseases such as Alzheimer's and Parkinson's diseases. Curcumin possesses a spectrum of antioxidant, anti-inflammatory, anticarcinogenic, and antimutagenic properties. Because of this broad spectrum of pharmacological activity, it has been suggested that, like cholesterol, curcumin exerts its effect on a rather basic biological level, such as on lipid bilayers of biomembranes. The effect of curcumin on translational mobility of lipids in biomembranes has not yet been studied. In this work, we used 1H NMR diffusometry to explore lateral diffusion in planar-oriented bilayers of dimyristoylphosphatidylcholine (DMPC) and dioleoylphosphatidylcholine (DOPC) at curcumin concentrations of up to 40 mol % and in the temperature range of 298-333 K. The presence of curcumin at much lower concentrations (∼7 mol %) leads to a decrease in the lateral diffusion coefficient of DOPC by a factor of 1.3 at lower temperatures and by a factor of 1.14 at higher temperatures. For DMPC, the diffusion coefficient decreases by a factor of 1.5 at lower temperatures and by a factor of 1.2 at higher temperatures. Further increasing the curcumin concentration has no effect. Comparison with cholesterol showed that curcumin and cholesterol influence lateral diffusion of lipids differently. The effect of curcumin is determined by its solubility in lipid bilayers, which is as low as 10 mol % that is much less than that of cholesteroĺs 66 mol %