Effects Of Benzyl Alcohol Research Articles

천연염료에 의한 모발염색에서 용매의 효과 (I)

Recently, there is a trend to utilize natural dyes in many dyeing fields. In this work, the effects of benzyl alcohol in human hair dyeing with cochineal, a natural dye, was investigated. We investigated the K/S value and color value of dyed hair, water retention of dyed hair, protein release-ability of dyed hair, and wash fastness of dyed hair according to dyeing time and temperature. The shade of dyed hair was reddish. By adding benzyl alcohol in cochineal dyeing, the dyeing rate was increased and the dyeing equilibrium was established at early stage. The water retention of dyed hair was increased and the protein release-ability of dyed hair was decreased, meaning that the hair was less damaged during dyeing, The dyed hair showed a good wash fastness.

Effects of Benzyl Alcohol on Aggregation of Recombinant Human Interleukin-1-Receptor Antagonist in Reconstituted Lyophilized Formulations

A major limitation in the successful development of multidose protein formulations is protein aggregation induced by antimicrobial preservatives such as benzyl alcohol, which are included to maintain product sterility. Studies were conducted to evaluate the strategy of developing lyophilized formulations of a therapeutic protein, recombinant human interlukin-1 receptor antagonist (rhIL-1ra), to be reconstituted with a bacteriostatic amount (0.9% w/v) of benzyl alcohol in water. The strategy was based on the following hypotheses. The first was that benzyl alcohol would foster aggregation during reconstitution of the lyophilized sample. The second hypothesis was that the extent of benzyl alcohol-induced protein aggregation would correlate directly with the degree of structural perturbation of rhIL-1ra in the dried solid after lyophilization. Differential structural retention of rhIL-1ra in the dried solid was obtained by using a combination of formulation variables important for lyophilization and included: protein concentration, type of stabilizer, and presence or absence of NaCl. Infrared spectroscopic analysis of the lyophilized samples indicated that high initial solution protein concentration and the stabilizer sucrose minimized structural perturbation of rhIL-1ra during lyophilization. In contrast, NaCl was destabilizing. Reconstitution of the dried solid with 0.9% (w/v) benzyl alcohol caused a greater degree of protein aggregation than reconstitution with water, confirming our first hypothesis. In support of our second hypothesis, the extent of aggregation induced by benzyl alcohol during reconstitution was strongly modulated by the degree of retention of native rhIL-1ra secondary structure during lyophilization. During storage of the reconstituted lyophilized samples at room temperature, benzyl alcohol did not accelerate aggregation of rhIL-1ra. This study demonstrated that for development a multidose lyophilized protein formulation involving reconstitution with a solution of benzyl alcohol, protein structural perturbations during freeze-drying should be minimized with a stabilizing excipient and appropriate choice of protein concentration and tonicity modifier. Furthermore, postreconstitution storage at reduced temperature (e.g., room temperature or 4°C) could minimize the risk of preservative-induced protein aggregation.

Cold shock in Bacillus subtilis: different effects of benzyl alcohol and ethanol on the membrane organisation and cell adaptation

A temperature shift-down of Bacillus subtilis from 40 to 20°C induces an 80 min growth lag. Benzyl alcohol reduced this period to 51 min, whereas ethanol prolonged it up to 102 min. The effect of the two alcohols on the membrane state was investigated by measuring the steady-state fluorescence anisotropy and analysing the lifetime distribution of diphenylhexatriene (DPH) and its polar derivative, TMA-DPH. As followed from the fluorescence anisotropy, the two alcohols exerted similar (fluidising) effects on the cytoplasmic membranes of B. subtilis. However, benzyl alcohol significantly shortened the main DPH lifetime component and widened its distribution, while ethanol had no effect. The benzyl alcohol activity was interpreted in terms of an increased membrane hydration due to disordering of the membrane structure. Such an effect imitates the cold shock induced synthesis of unsaturated fatty acids in B. subtilis. The fatty acid analysis revealed that ethanol hindered this adaptive synthesis of fatty acids. At the same time, its effect on the membrane state (membrane order) was very low and could not substitute the physiological response as was the case with benzyl alcohol. It can thus be concluded that the adaptation of the membrane physical state contributes significantly to the cold shock response of B. subtilis.

Modulation of organic cation transport and lipid fluidity by benzyl alcohol in rat renal brush-border membranes.

Organic cations are actively transported in renal brush-border membranes (BBM) by the H+/organic cation antiport system. In the present study, we investigated the relationship between membrane fluidity and organic cation transport in the BBM. The effects of benzyl alcohol, a membrane fluidizing agent, on the organic cation tetraethylammonium (TEA) uptake were studied using renal BBM vesicles isolated from rat kidney. BBM fluidity was assessed by fluorescence polarization technique. H+ gradient-dependent uptake of TEA in BBM vesicles was inhibited by benzyl alcohol in a dose-dependent manner, with an apparent half inhibitory concentration of 18mM. The decrease in fluorescence anisotropy of 1,6-diphenyl-1,3,5-hexatriene in BBM, which represents the increase in membrane fluidity, was correlated with the decrease in TEA transport activity. The dissipation rate of H+ gradient, a driving force for organic cation transport in BBM, was increased by benzyl alcohol. In addition, H+ gradient-independent TEA-TEA exchange was also inhibited by benzyl alcohol. These findings indicate that benzyl alcohol inhibits the uptake of TEA by affecting the intrinsic activity of the organic cation transporter and the H+ gradient dissipation rate. The membrane fluidity should be an important determinant for organic cation transport in renal BBM.

Cosolvency effects of benzyl alcohol and heptane on the formation of macroporous styrene-divinylbenzene copolymers

Styrene-divinylbenzene copolymers were synthesized by suspension polymerization in the presence of benzyl alcohol (BA) and hepatane (Hep). The influence of BA/Hep ratio, dilution degree and DVB content on the formation of porous structure and swelling of the copolymers were investigated. The results were interpreted according to the solubility parameter theory.

Effects of Benzyl Alcohol on Wool Dyeing.

Benzyl alcohol (BA) was used as a cosolvent in the solvent-assisted dyeing of wool with acid dyes having surface activity different from that of BA. The equilibrium exhaustion of Orange II having surface activity lower than that of BA decreased with increasing BA concentration in the dye-bath, although the rate of dyeing at the initial stage was accelerated by BA. On the other hand, the adsorption of Butyl Orange having surface activity higher than that of BA was increased by the addition of BA in all the stages of dyeing. These results correspond approximately to the adsorption behavior of BA/acid dye mixture at an air/water interface, showing that these phenomena were caused mainly by the difference in the dye concentration at a wool/dye-bath interface similar to that at the air/water interface.

Effect of benzyl alcohol on phospholipid transverse mobility in human erythrocyte membrane.

The effect of benzyl alcohol on the transverse mobility and repartition of phospholipids in the human erythrocyte membrane was investigated using electron spin resonance and morphological modification of red blood cells. Transmembrane internalization rates and equilibrium distribution in red blood cells of short-chain spin-labeled phosphatidylcholine, phosphatidylethanolamine and phosphatidylserine were strongly modified by treatment with 10-70 mM benzyl alcohol. A dual effect was observed: (a) at 4 degrees C and 37 degrees C there was an N-ethylmaleimide-sensitive, long lasting and fully reversible increase in the spin-labeled phosphatidylserine and phosphatidylethanolamine internalization rate; (b) at 37 degrees C, an enhancement of N-ethylmaleimide-insensitive fluxes of all the labeled phospholipids through the membrane occurred. Both effects were dose-dependent. Erythrocytes submitted to benzyl alcohol incubation also showed dose-dependent shape changes: an immediate one from discocytes to echinocytes, followed by a slower N-ethylmaleimide- and ATP-dependent change to stomatocytes. Moreover, benzyl alcohol treatment was shown to lead to enhanced hydrolysis of intracellular ATP. All the effects of benzyl alcohol can be described as an accumulation of labeled phosphatidylethanolamine (and labeled phosphatidylcholine at 37 degrees C) in the inner leaflet. This can be interpreted as a perturbation of the erythrocyte membrane, leading to an energy-consuming specific increase in aminophospholipid translocase activity, in addition to a slow and passive bidirectional flux of all phospholipids at 37 degrees C.

Effects of benzyl alcohol on transferrin and low density lipoprotein receptor mediated endocytosis in leukemic guinea pig B lymphocytes

We demonstrated that benzyl alcohol, a neutral local anesthetic drug, inhibits the uptake and degradation of lowdensity lipoprotein and endocytosis of transferrin receptors of guinea pig leukemic B lymphocytes (L 2C). This inhibition is very rapid, concentration dependant and reversible by simple washing. Membrane fluidity of the living cells is also modified.

Effects of benzyl alcohol on enzyme activities and d-glucose transport in kidney brush-border membranes

Addition of increasing amounts of benzyl alcohol progressively reduced the steady-state anisotropies of diphenylhexatriene and trimethylammoniumdiphenylhexatriene in brush-border membranes from rat kidney. The decrease in order of membrane lipids, equivalent for 50 mM benzyl alcohol to that produced by a rise in temperature of approx. 6°C, had no effect on the activities of alkaline phosphatase or γ-glutamyltranspeptidase. On the other hand, benzyl alcohol markedly inhibited the d-glucose uptakes measured in the presence of a 100 mM sodium gradient. For concentrations less than 30 mM, benzyl alcohol reduced the J max without significant effects on K m, 22Na + uptake or the vesicular volume of brush-border preparations. Comparable results were obtained substituting octanol for benzyl alcohol. Our data strongly suggest that, at constant temperature, the d-glucose carrier present in renal brush-border membranes is extremely sensitive to variations in membrane physical state.

The effect of benzyl alcohol and cholesterol on the acyl chain order and alkane solubility of bimolecular phosphatidylcholine membranes

An investigation was made of the effects of cholesterol and benzyl alcohol on the partitioning of n- alkanes between lipid bilayer membranes and bulk lipid/alkane solutions (in the torus). Bilayers were formed from solutions containing alkanes of different chain lengths, together with phosphatidylcholine and cholesterol in varying proportions. The partitioning of the alkanes was determined from measurements of the very low frequency (1 Hz) capacitance of the membranes. Perturbation of the internal membrane structure by the inclusion of cholesterol and benzyl alcohol produced very significant changes in the n- alkane partition coefficient, cholesterol causing a decrease and benzyl alcohol an increase in the alkane partitioning into the bilayer. A correlation exists between the effects of these compounds on the alkane partitioning and their effect on the segmental chain order of the acyl chains in the bilayer and this correlation is consistent with a statistical-mechanical model of the lipid/alkane bilayers in the liquid crystalline state. The perturbation by cholesterol and benzyl alcohol of the internal structure of membranes bears on the conflicting reports of the effects of these substances on artificial lipid bilayers and could also be relebant to their known physiological effects.

Effects of benzyl alcohol on erythrocyte shape, membrane hemileaflet fluidity and membrane viscoelasticity

The effects of benzyl alcohol on cell shape, hemileaflet lipid fluidity and membrane rheology of human red blood cells were studied. Membrane fluidity was assessed by determining the fluorescence anisotropy of permeant probes (1,6-diphenyl-1,3,5-hexatriene, 12-(9-anthroyloxy)stearate, 2-(9-anthroyloxy)stearate) and a new impermeant probe ( N-stachyosylsuccinic acid dihydrazide-2-(9-anthroyloxy)stearate). Measurements made on intact red blood cells reflected primarily the outer leaflet fluidity while measurements made on red blood cells ghosts reflected the fluidity of both leaflets. Membrane viscoelasticity was determined by micropipette aspiration. Treatment of intact red blood cells with benzyl alcohol up to 50 mM caused progressive stomatocytic shape change but no change in membrane viscoelasticity, 1,6-diphenyl-1,3,5-hexatriene anisotropy or stachyosyldihydrazide-2(9-anthroyloxy)stearate correlation time; similar treatment of leaky ghosts yielded decreases in 1,6-diphenyl-1,3,5-hexatriene anisotropy and stachyosyldihydrazide-2(9-anthroyloxy)stearate correlation time. With benzyl alcohol above 50–60 mM, intact red blood cells became echinocytic, and decreases in 1,6-diphenyl-1,3,5-hexatriene anisotropy and stachyosyldihydrazide-2(9-anthroyloxy)stearate correlation time occurred in both intact cells and ghosts; there was no change in membrane viscoelasticity. These results indicate that benzyl alcohol up to 50 mM affects primarily the inner leaflet of the red blood cell membrane and that higher concentrations affect both leaflets. These increases in membrane fluidity are not associated with changes in membrane viscoelasticity. This study illustrates the use of fluorescence techniques to monitor specifically the lipid fluidity of each hemileaflet of the erythrocyte membrane.

Benzyl Alcohol as Preservative for Intravenous Solutions

Benzyl alcohol is commonly used as an antibacterial agent in a variety of formulations including bacteriostatic sodium chloride and bacteriostatic water. Although benzyl alcohol toxicity has been recognized, the concentration necessary for antibacterial action appears to be much lower than the concentration that would be dangerous to adults. Prior to these reports, little was known about the toxic effects of benzyl alcohol in neonates. The possible toxic effects of benzyl alcohol in neonates were noted when several premature infants in neonatal intensive care units developed similar clinical syndromes, referred to as the "gasping syndrome," characterized by deterioration of multiple organ systems and eventual death.

Effects of benzyl alcohol on phosphatidylcholine lamellar phase with different water contents

Effects of benzyl alcohol (BA) on the bilayer thickness d 1 and the fluidity of egg phosphatidylcholine (PC) lamellar phase with various water contents have been studied by X-ray diffraction and the proton spin-lattice relaxation rate. At lower water contents; BA causes d 1 to decrease and the rate of molecular motions to increase. By contrast, with increasing BA at excess water, d 1 remains nearly unchanged, though the rate of motions increases. Hydration experiment for egg phosphatidylcholine lamellae with BA at a 1:1 molar ratio shows that in the range from 15% to 30% water, d 1 decreases to the value of the fully hydrated sample without BA and is nearly constant above 30% water. The value at full hydration is suggested to be a lower limit of the bilayer thickness, the chain is in the unperturbed state. It is in an extended structure at lower water contents. This leads to the difference in the effect of BA on the bilayer thickness at different water contents.

The molecular organisation of bimolecular lipid membranes. The effect of benzyl alcohol on the structure

The separate effects of benzyl alcohol on the hydrocarbon and polar-head region capacitances and conductances of phosphatidylcholine bimolecular lipid membranes were obtained from measurements of the very low frequency impedance dispersion. It was found that the conductance of the hydrocarbon region (and, to a lesser extent, the polar-head region) increased progressively with increasing concentrations of benzyl alcohol in the external solution. The polar-head capacitance did not show a systematic dependence on the concentration of benzyl alcohol. At low concentrations of benzyl alcohol (7.5 μM) the capacitance of the hydrocarbon region was not significantly affected by the alcohol. At high concentrations (⩾ 7.5 mM) of benzyl alcohol, however, the capacitance of this region was reduced by ≈25%. This is interpreted in terms of an increase in the thickness of this region caused by a straightening of the otherwise kinked, folded (across neighbouring molecules) and perhaps even partially interdigitated hydrocarbon tails of the phosphatidylcholine molecules. This effect of benzyl alcohol is probably closely related also to the apparent increase in the fluidity of the membrane. The effect of benzyl alcohol on the thickness of the hydrocarbon region of the membrane provides a ready insight into its mode of action as a local anaesthetic.

Effects of benzyl alcohol on the bovine oestrous cycle and subsequent fertility.

A uterine infusion varying in volume from 5 to 40 ml and containing from 0.5 to 2.0 ml of benzyl alcohol shortened the length of the oestrous cycle in cows treated in the early luteal phase and prolonged the oestrous cycle in some cows in the late luteal phase. Results with 399 infusions produced a concentration of cows in oestrus from 8 to 13 days after treatment. The conception rate for 198 inseminations at the first post-treatment oestrus was 59.6% compared to 59.2% obtained in 471 untreated cows.