原子类型电拓扑指数在脂肪醇类化合物毒性预测研究中的应用

采用原子类型电拓扑指数(ETSIAT)为结构描述子, 对梨形四膜虫、番茄、红蜘蛛、发光细菌荧光素酶、呆鲦鱼以及鼠的脂肪醇毒性进行了定量构效关系(QSAR)研究. 在偏最小二乘法建立QSAR模型的基础上, 采用内部和外部两种验证方法对模型进行验证. 研究结果表明: ETSIAT可以很好地表征脂肪醇与多种生物毒性相关的结构信息, 所建模型具有良好的稳定性和外部预测能力. 偏最小二乘模型分析结果显示: 疏水性可能是影响脂肪醇毒性大小的主要因素, 其毒性随C链长度的增加而增强, 且相同C原子数的直链脂肪醇毒性明显高于支链脂肪醇; 由于空间位阻效应, 长链脂肪醇与短链脂肪醇可能存在不同的毒性作用机理.     

Tensammetric studies of alcohols with reference to their structural influence on surface activity

Summary This work relates to the tensametric studies of various aliphatic alcohols with a view to see if this technique can be used to assess the structural influence on surface activity. From the study of the homologous series of aliphatic alcohols, it is seen that the surface activity increases with increase in chain length of the alcohols. With lower members of the series the desorption peak is not sharp. There is no regular shift of peak potential from methanol to amylalcohol. For the same alcohol the surface activity increases if the carbon atoms are in a straight chain but decreases if they are branched. Primary alcohols are more surface active than secondary and secondary are more surface active than tertiary alcohols. The peak potential is more negative for normal alcohol than that of tertiary alcohol. Saturated alcohols are more surface active than unsaturated ones having the same number of carbon atoms. The peak potential is also more negative with saturated than with unsaturated. Monohydric alcohols are more surface active than dihydric and dihydric is more surface active than trihydric alcohol having the same number of carbon atoms as in monohydric and dihydric alcohols and in this case the peak potential is more negative with trihydric than with monohydric alcohol.     

Identification by combined gas chromatography-mass spectrometry of constituent long-chain fatty acids and alcohols from the meibomian glands of the rat and a comparison with human meibomian lipids

Constituent long-chain fatty acids and alcohols from the meibomian secretions of the rat were examined as trimethylsilyl (TMS) and methyl ester-TMS derivatives by capillary gas chromatography and by combined gas chromatography-mass spectrometry. The positions of double bonds and methyl branch points were determined by the mass spectra of picolinyl esters and nicotinates for long-chain fatty acids and alcohols, respectively. Fatty acids had chain lengths from C12 to C34 and were of the straight-chain iso, anteiso and monounsaturated types. The unsaturated acids had double bonds in the omega-7 and omega-9 positions. The alcohols had corresponding structures. In common with the constituent acids and alcohols of other meibomian secretions, the chain lengths of the constituents showed a biphasic distribution with maxima around C16-C18 and C25-C27. The profile was qualitatively similar to that obtained from human meibomian secretion but with some differences in the relative proportions of certain acids and alcohols.     

Preparation of liquid crystal emulsion and its application performance study

The aim of this study was the formulation composition and characterization of the liquid crystal (LC) emulsion. First, influences of formulation composition on preparation of LC structure were studied, including the aliphatic alcohols with different carbon chain length, the liquid oils with different polarities, the sodium chloride, and the polygons. The results showed that fatty alcohols which is closer to the hydrophobic group of the emulsifier, little liquid oil, and little polyols were conducive to form LC structure. Then, the application performance of LC structure emulsion was studied. The results showed that compared with the conventional structure emulsion, the LC structure emulsion had more excellent moisturizing property, slow release effect, and the promoted penetration effect.     

Ice nucleation by monolayers of aliphatic alcohols

Monolayers of aliphatic long chain alcohols (C_nH_2n+1OH) were found to induce nucleation of ice at temperatures approaching O°C in contrast to water-soluble alcohols which are efficient antifreeze agents. The corresponding fatty acids and alcohols with bulky hydrophobic groups, induce ice nucleation at temperatures lower by as much as 12°C. The freezing point induced by the amphiphilic alcohols was found to be sensitive not only to area per molecule but also to chain length and parity, reaching higher temperatures for monolayers with n odd. Grazing incidence X-ray diffraction studies performed on some of these alcohols at the air/water interface (at 5°C and at zero pressure), demonstrated the formation of crystalline two-dimensional clusters with a distorted hexagonal cell whose dimensions resemble those of hexagonal ice. The catalysis of ice nucleation by these alcohol monolayers may be rationalized in terms of the structural match between the monolayer domains and the ab layer of hexagonal ice.     

Features of the reaction of polyfluoroalkyl chlorolsulfites with allyl alcohol

Unlike the saturated aliphatic and aromatic alcohols, allyl alcohol under the same conditions reacts with polyfluoroalkyl chlorosulfites to form not ethers, but polyfluorinated alcohols. The exception is polyfluoroalkyl chlorosulfites with the chain length of more than five carbon atoms. Allyl ethers of polyfluorinated alcohols of general formula CH₂=CHCH₂OCH₂(CF₂CF₂)nH (n = 1–3) were obtained, when the reaction proceeded in the presence of potassium carbonate, owing to its participation in a specific orientation of the reaction centers in the resulting intermediate structure, which is easily transformed into allyl ethers of polyfluorinated alcohols.     

Complexes of short-chain alcohols withβ-cyclodextrin

The complex formation of β-cyclodextrin with short chain aliphatic alcohols has been studied. The stability constants of 1∶1 complexes, determined spectrophotometrically, increase monotonically in the series of normal alcohols, while branching in the chain results in a further increase in stability. With smaller monoalcohols, complexes containing more than one guest molecule are formed as well, but the relative stability of these complexes decreases with increasing chain length and branching. The stabilities of 1∶1 complexes decrease with an increasing number of OH-groups, probably due to a stronger hydration. This reflects both the roles of space filling and hydrogen bridging     

Antimycobacterial activity of steroids, long-chain alcohols and lytic peptides

As a continuation of our project aimed at a search for new antimycobacterial agents, several naturally occurring and synthetic compounds have been evaluated against Mycobacterium tuberculosis H37Rv and M. avium. Emphasis was placed on steroids and a series of isoprene long-chain alcohols to gain new insight into their structural activities. Maximum activity of isoprenoid derivatives seemed to depend on the hydrophobic chain length from the hydrophilic hydroxyl moiety. In contrast, ergosterol peroxide produced significantly greater inhibition than the corresponding steroids. Bile acids, amino acid-based surfactants and cholesteryl esters possessing different alkyl side chains were surprisingly the least effective. Encapsulation of compounds in cyclodextrins did not lead to significant loss in activity. Considering the inhibitory activity observed for the active steroids and isoprene long-chain alcohols, the phytyl moiety appeared to be critical for maximum activity. The implications of these findings for the rational design of new antituberculosis agents are briefly discussed.     

Catalytic C(1), C(2)-Bond Cleavage of Long-Chain Aliphatic Alcohols and ω-Phenylalkyl Alcohols

A catalytic one step procedure for the C(1), C(2)-bond cleavage of long-chain aliphatic alcohols and ω-phenyl alcohols has been investigated, using as examples decanol, dodecanol, hexadecanol, benzyl alcohol, 2-phenylethanol and 3-phenyl-propanol. The reactions, which were carried out in a continuous flow tubular reactor using a Ni/Cu catalyst, showed good activity and selectivity with respect to the cleavage products. On the basis of the experimental studies a reaction scheme for the heterogeneous catalytic C(1), C(2)-bond cleavage of the alcohols is suggested.     

醇和N,N-二甲基乙酰胺分子间相互作用的FTIR光谱研究

The association between alcohols and N,N-dimethylacetamide in carbon tetrachloride was investigated using FTIR spectroscopy at 298 K.The formation constants for 1∶1 and 1∶2 complexes were calculated using the method of Whetsel and Kagarise.The observed 1∶1 complex values were also verified using the method of Nash.The rate of change in C=O bond moment on complexing with alcohols increased with increasing acidity of alcohols.The formation constant and values of free energy change increased with the increase in carbon chain length of alcohols,which suggested that the degree of complex formation varied with the length of the carbon chain of alcohols.     

正态分布脂肪醇壬乙氧基醚混合溶液的表面吸附与胶束形成

正态分布的C₁₀-C₁₈脂肪醇壬乙氧基醚(AE₉)多元混合溶液的热力学参数,按正规溶液非理想混合式计算更符合实际。调节憎水基烷基链长的分布,可有效地提高组份间的协合作用。     

Activity,Selectivity, Decay and Long-Term Behaviour of Amination Catalysts

A survey of the activity and selectivity of several catalysts for the amination of long-chain aliphatic alcohols with dimethylamine is given. The best results were obtained with Cu-catalysts whose long-term behaviour was investigated. The main reasons for catalyst decay are the irreversible adsorption of dimerization products and the thermal diffusive fusion of Cu-crystallites.     

Chemical composition of angelica root oil.

The volatile constituents of angelica root separated by extraction with etherpentane and by extraction with alcohol-water were investigated by means of glass capillary and preparative gas chromatography, IR, UV, NMR and mass spectrometry. 16 monoterpene hydrocarbons, 13 sesquiterpene hydrocarbons, 12 monoterpene alcohols, 4 oxygenated sesquiterpenes, 11 esters, 3 lactones, 7 aliphatic carbonyl compounds and 4 aromatics were identified. Twenty additional compounds identified were present only in the alcoholic sample. These consisted of ethyl ethers of monoterpene alcohols, ethyl esters of long-chain fatty acids, and acetals. The relative proportion of many compounds was found to depend on the method used to isolate the essential oil.     

Nanostructure changes in protic ionic liquids (PILs) through adding solutes and mixing PILs

The effect of adding primary n-alcohols with aliphatic chains and hexane on the nanostructure of a series of 14 protic ionic liquids (PILs) was explored using small and wide angle X-ray scattering (SAXS and WAXS). PILs were investigated with primary, secondary and tertiary ammonium cations containing different alkyl chain lengths, with and without hydroxyl substitution of the alkyl chain. Formate or nitrate anions were paired with these cations. The PILs which had no identified intermediate range order between 5-16 ? had very low solubilities of the solutes. The other PILs, which had non-polar domains present, were mostly miscible with the primary alcohols of ethanol, propanol and butanol. When the alkyl chain length of the alcohols was similar to the PILs then the alcohols co-partitioned with the alkylammonium cation components of the PILs and caused either an increase or decrease in the size of the non-polar domains, depending on whether the alcohol chain length was longer or shorter than that of the cation in the PIL respectively. For ethylammonium nitrate (EAN) with propanol or butanol and propylammonium nitrate (PAN) with butanol, the difference between the alcohol chain length and the alkyl chain length was too great to lead to a modified nanostructure, and instead large aggregates were present. The solubility of hexane in the alkylammonium nitrate PILs had a very strong correlation to the alkyl chain length. The addition of hexane had very little effect on the non-polar domain sizes, which was attributed to it not being orientated in alignment with the alkylammonium cations in the non-polar domains. Lastly, seven binary PIL-PIL solution series were investigated using SAXS and WAXS to show how the nanostructure of these systems can be fine tuned to control the size and structure of the non-polar domains.     

Long-chain fatty alcohol quantitation in subfemtomole amounts by gas chromatography-negative ion chemical ionization mass spectrometry. Application to long-chain acyl coenzyme A measurement

We describe a simple and sensitive method to identify and quantitate long-chain fatty alcohols. Long-chain fatty alcohols were converted to their pentafluorobenzoyl derivative and analyzed by gas chromatography (GC)-mass spectrometry in the negative ion chemical ionization (NICI) mode with selected ion monitoring. GC resolution was obtained for myristyl, palmityl, heptadecyl, stearyl, oleyl, linoleyl and arachidonyl alcohols. As little as 0.4 fmol of fatty alcohol can be detected, which represents a six order-of-magnitude increase in sensitivity over previously described methods. This assay can be used to measure femtomolar amounts of long-chain acyl coenzyme A thioesters after reduction to the corresponding fatty alcohols with sodium borohydride. Other potential applications of this assay include identification and quantitation of long-chain fatty alcohol production by microorganisms.     

有效碳链长度与脂肪醇的沸点

脂肪醇沸点(b.p.)变化规律可用下述关系式表示:ln(800.386-T~b)=6.64919-2.94828×10^-^2N~E~C~C+0.150955ΔPEI。式中N~E~C~C为醇中烷基的有效碳链长度, ΔPEI是具有相同碳原子数目的支链烷基与直链烷基的极化效应指数的差值, 它表示羟基对醇的沸点的影响。     

Systematic characterisation of long-chain aliphatic esters of wool wax by gas chromatography-electron impact ionisation mass spectrometry

A detailed structural characterisation of the aliphatic high-molecular-mass esters extracted from raw wool based on high-temperature gas chromatography-electron impact ionisation mass spectrometry is described. The raw wool esters extracted are in the range of C37 to C54 (i.e., molecular mass 550-788). The selected ion chromatogram exhibited four isomers for the esters with an odd number of carbon atoms (i:a, i:n, a:n and n:n) and five for those with an even number of carbon atoms (i:i, a:a, i:n, a:n and n:n). Isomeric structural elucidation is discussed with respect to the long-chain fatty acid and long-chain fatty alcohol structures, on the basis of chromatographic retention behaviour and mass spectral information.     

A MICROEMULSION COSURFACTANT WITH EXCELLENT WATER SOLUBILIZATION AT HIGH OIL CONTENT

Medium chain length alkyl amines were found to be more effective cosurfactants for microemulsion formation than are medium chain length alcohols at high hydrocarbon levels with sodium doecyl sulfate as the surfactant. Both aromatic and short chain aliphatic hydrocarbons were studied. By contrast, the amines were found virtually Ineffective with quaternary anmoniutn salts whereas the alcohols showed good performance. This suggests the possibility that complementarity of function between surfactant and cosurfactant may be a desirable feature of a microemulsion system at high hydrocarbon levels.     

On the interaction of dipalmitoyl phosphatidylcholine with normal long-chain alcohols in a mixed monolayer: a thermodynamic study

This study investigated the mixed monolayer behavior of dipalmitoyl phosphatidylcholine (DPPC) with normal long-chain alcohols at the air/water interface. Surface pressure–area isotherms of mixed DPPC/C₁₈OH and DPPC/C₂₀OH monolayers at 37°C were obtained and compared with previous results for the mixed DPPC/C₁₆OH system. The negative deviations from additivity of the areas and the variation of the collapse pressure with composition imply that DPPC and long-chain alcohols were miscible and formed non-ideal monolayers at the interface. At lower surface pressures, it seems that the attractive intermolecular force was dominant in molecular packing in the mixed monolayers. At higher surface pressures, the data suggest that the molecular packing in mixed DPPC/C₁₆OH monolayers may be favored by the packing efficiency or geometric accommodation. Furthermore, negative values of excess free energy of mixing were obtained and became significant as the hydrocarbon chain length of alcohols increased, which indicates there were attractive interactions between DPPC and long-chain alcohols. In each free energy of mixing–composition curve, there was only one minimum and thus a phase separation did not exist for mixed DPPC/long-chain alcohol monolayers.     

Some Aspects of Ionic Liquids as Diverse and Versatile Sustainable Solvents

In this mini review several particular cases of ionic liquid solution behavior are discussed, namely solutions of ionic liquids with aliphatic alcohols, polyalcohols, arenes, chloromethanes and poly(ethyleneglycol) as well as salting-out and salting-in effects. The presented cases clearly expose ionic liquids as being diverse and versatile sustainable solvents that exhibit flexible phase behavior and, consequently, variable phase diagrams. These can be tuned either by changing the length of the alkyl chain(s) of the ionic liquid??s cation (and/or sometimes the anion), or by introducing a different aliphatic nature to the other solution constituent (e.g., by varying polymer chain length or the number of carbon atoms in chloromethanes). Sometimes, the evolution of the phase diagrams is fine and continuous, showing several consecutive stages, revealing both qualitative and quantitative changes. Finally, the diversity and versatility of ionic liquids are viewed as important features that contribute to their efficiency as tunable solvents or salting media.