Aminimides: I. Antimicrobial effect of some long chain fatty acid derivatives

Aminimides are a new class of surface active agents which have antimicrobial activity. These bipolar compounds have activity against both gran-positive and yeast organisms. Their activity against gram-negative organisms is low or absent. The acyl derivatives tested showed maximum activity at chain lengths of C₁₄ and C₁₆. Fatty acid derivatives, shorter (14) or longer (>C₁₆), were less active. Unsaturation was an important factor contributing to aminimide activity. Their low toxicity and wide spectrum of antimicrobial activity make aminimides ideal candidates for further investigation.     

Antimicrobial activity of some fatty acid derivatives

Twelve fatty acid amide or ester derivatives were screened for antimicrobial activity against a grampositive bacterium,Staphylococcus aureus; a gramnegative bacterium,Escherichia coli; a mold, eitherAspergillus flavus orA. species; and a yeast, eitherCandida albicans orTorula species. These compounds were adducts of unsaturated fatty derivatives in which the addends were hexachlorocyclopentadiene, thiolacetic acid, bromotrichloromethane, or O,O-diethylphosphorodithioic acid. All of the new compounds appreciably inhibited the activity of at least one of the test organisms, and most of them showed activity against all four types of organisms. The hexachlorocyclopentadiene adduct of 2-(2-ethoxyethoxy)ethyl oleate was especially potent in this regard.     

Thermal oxidation of mono-unsaturated short chain fatty acids: II. Methyl hexenoate,hexenoic acid,and octenoic acid

Samples of methyl 3-hexenoate, methyl 2-hexenoate, 3-hexenoic, and 3-octenoic acid were oxidized and their decomposition products analyzed. Certain aldehydes, ketones, shorter chain acids or esters, hydroxy-derivatives, and dimers were found among the oxidation products of all four substrates. Epoxyesters and 4-oxo-derivatives were major products from the esters but absent in the case of the acids. 3-heptene and 5-undecene were unique for 3-hexenoic and 3-octenoic acids, respectively. Reaction mechanisms are proposed for the formation of these products.     

Aminimides: III antimicrobial effect of various hexadecyl and quaternary derivatives

Aminimides, a new class of surfactants, have been screened for in vitro antimicrobial activity. Greatest activity against gram (+) and yeast organisms is achieved when a chain length of C₁₆ is reached. This generalization is true whether or not the chain length is joined to the imide or amine group. The type of functional group associated with the surfactant is less important than chain length. Gram (-) organisms do not fit this generalization, since shorter (<C₁₆) rather than longer chain derivatives are more active. The importance of surfactant chain length to biodegrad-ability is discussed.     

Non-volatilea-branched chain fatty acid derivatives: IV. Addition of aryl esters to long chain olefins

The di-tertiary butyl peroxide initiated free radical addition of methyl phenylacetate, methylp-tolylacetate and methylp-methoxyphenylacetate to 1-decene gives two types of products. In addition to the expecteda-branched esters, dehydrodimer (bothmeso anddl) esters were also obtained. The highest yield ofa-branched ester was obtained from methyl phenylacetate. Higher yields of the dehydrodimer esters were obtained from the substituted phenyl esters. Attempts to add methylp-nitrophenylacetate to 1-decene were not successful and no evidence for the formation of a dehydrodimer product was observed.     

Nonvolatilealpha-branched chain fatty esters. II

A group of nonvolatilealpha-branched esters was prepared by the di-tertiary butyl peroxide-promoted addition of normal esters to terminal olefins containing methyl branches or aryl groups. Methyl stearate was added to 3,7-dimethyl-1-octene, 3,5,5-trimethyl-1-hexene, and 4-phenyl-1-butene. The reaction with 2,4,4-trimethyl-1-pentene, a terminal alkene with a methyl branch at the internal ethylenic carbon, was not successful. Benzyl 2-(4-phenylbutyl) octadecanoate was prepared by transesterification of the corresponding methyl ester. Benzyl 2,2-dimethylpropanoate, which has no α-hydrogen in the acyl portion of the molecule, was added to 1-hexadecene to form α-hexadecylbenzyl 2,2-dimethylpropanoate. Lubricant evaluation data were obtained on the above compounds. Presented at the AOCS Meeting, New Orlenas, May 1967. E. Utiliz. Res. Dev. Div., ARS, USDA.     

Properties of vinyl ester resins containing methacrylated fatty acid comonomer: the effect of fatty acid chain length

This paper reports the formulation of a low‐cost vinyl ester‐based composite resin suitable for liquid molding, which has significantly lower volatile organic compound emission associated with it. Methacrylated fatty acid comonomers were used to replace the conventional yet environmentally hazardous reactive diluent, styrene. The chain length of these fatty acids played a key role in obtaining better viscosity, as it was proved to affect two interplaying factors: intermolecular friction and hydrogen bonding. The thermomechanical performance was greatly affected by the chain length of the fatty acids as well as the crosslink density of the polymer networks. A carbon number of 6 to 8 was good enough in optimizing the viscosity parameter suitable for handling; the dynamic mechanical analysis values, namely glass transition temperature and storage modulus, were in the range 66–121 °C and 0.97–2.8 GPa, respectively, as the carbon number was varied from 4 to 16, making the material suitable for various applications. Microstructures obtained from scanning electron microscopy results were correlated with polymer properties to obtain a better insight into these polymer networks. Copyright © 2007 Society of Chemical Industry     

Nonvolatile α-branched chain fatty acid derivatives: III. Addition of acid chlorides,anhydrides and amides to terminal olefins

At-butyl peroxide initiated free radical reaction was employed for the preparation of α-branched fatty acid chlorides, which were then converted in situ to methyl esters. Similarly prepared were an α-branched fatty acid amide and an α-branched acid anhydride. The latter was converted to the methyl ester. The use of the acid chloride and acid anhydride permitted reduction in the molar ratio of reactants to half or less than that used in the addition of esters to terminal olefins without affecting the yield. The resulting increase of α-branched product concentration in the reaction mixture also made isolation of the product easier. The direct addition of a variety of stearic acid derivatives to 1-decene under the same conditions (20:4:1.2 molar ratio of reactants at 160 C) gave the following olefin based yield order: stearoyl chloride > stearic anhydride > stearamide and methyl stearate > stearic acid. Presented at the AOCS Meeting, Chicago, October 1967. E. Utiliz. Res. Dev. Div., ARS, USDA.     

Thermal oxidation of mono-unsaturated short chain fatty acids: I. ethyl 3-hexenoate

Ethyl 3-hexenoate was oxidized for 6 hr at 150 C. The “mor volatile” fraction was swept out of the oxidizing flask and into a cold trap. The “less volatile” products remaining in the oxidizing flask were isolated by direct injection onto a preparative-scale gas chromatographic column followed by trapping in glass capillary tubes. The decomposition products were identified by gas chromatography, mass spectrometry, infrared spectrophotometry, and chemical derivatization. The major products included epoxy esters, unsaturated keto- and hydroxy-esters, and dehydrodimers. Aldehydes, short chain esters, and ketones were produced less abundantly. No aldehyde esters were detected.     

Synthesis of mono- and di-functional silicon containing derivatives of long chain fatty acid esters

The addition products of some monochlorosilanes to methyl oleate and undecanoate were hydrolyzed and condensed to yield the corresponding difunctional disiloxanes, which were, inturn, transformed by alkaline hydrolysis or reduction to the corresponding diacids or diols. The addition products of dichlorosilanes gave on hydrolysis and condensation cyclosiloxanes but not linear polymers, as shown by mol wt data and IR spectra, while the corresponding addiiton products of trichlorosilances gave on similar treatment rubbery cross-linked polymers. In contrast to the silanol intermediates, obtained on hydrolysis of methylchlorosilanes, which condensed easily to the corresponding disiloxanes, the corresponding bulkier phenyl chlorosilanes gave stable silanols which showed a lower tendency to condense. Some mono-and di-alkoxy, phenoxy, and acetoxy silyl derivatives of the long chain fatty acid esters also were synthesized.     

Branched chain fatty acids and sulfonated derivatives

Several 2-alkyl fatty acids containing 18–21 carbon atoms, were synthesized by tertiary butyl peroxide catalyzed addition of linear aliphatic carboxylic acids to normal terminal olefins. The products obtained in 35–70% yields were purified by fractional distillation. The acids were sulfonated with sulfur trioxide dioxane adduct and isolated as the disodium salts in 60–80% yields.

$$ \begin{gathered} R - CH_2 CO_2 H + R'CH = CH_2 \xrightarrow[{125 - 160C}]{{Perioxide}}R'CH_2 CH_2 - CH(R)CO_2 H \hfill \\ R' - CH_2 CH_2 CH(R)CO_2 H + SO_3 \xrightarrow{{CCl_4 }}R'CH_2 CH_2 C(SO_3 H)(R)CO_2 H \hfill \\ \end{gathered} $$     

Antimicrobial activity of some ricinoleic acid oleic acid derivatives

Ricinoleic and acid oleic acid derivatives were screened for their antimicrobial activity, under optimum growing-conditions, against several species of bacteria, yeasts, and molds. Several ricinoleic acid derivatives and petroselinic (iso-oleic) acid exhibited considerable activity; in fact, their activity against some micro-organisms was comparable to sorbic and 10-undecenoic acid, known antimicrobial agents, as indicated by this test. One of the laboratories of the Southern Utilization Research and Development Division, Agricultural Research Service, U.S. Department of Agriculture.     

Chromatostrip analysis of fatty acid derivatives

Chromatostrips provide a rapid and convenient method of examination of samples by spot tests and by ascending or descending chromatography. Ascending chromatography for the examination of mixtures is carried out on 12×140-mm. glass strips coated with 5% starch-bonded silicic acid, while descending chromatography is done on 12×200-mm. strips. The 5% starch-bonded silicic acid coatings are resistant to normal handling, may be marked with a soft lead pencil, and may be stored indefinitely for reference. Three detection systems are employed: fluorescent minerals for conjugated unsaturates, fluorescein-bromine for unsaturates, and 2′,7′-dichlorofluorescein for all types of compounds. Positive tests result in characteristic spots when observed under normal or ultraviolet illumination. This permits the classification of components, after separation on the chromatostrips, into the groupings of conjugated unsaturated, unsaturated (or easily brominated), and saturated compounds.     

Aminimides IV: Antimicrobial activity of 1,1,1-Tris (2-hydroxyethyl) amine-2-acylimides

The newest member of the aminimide family of surfactants was screened for antimicrobial activity. The present report supports past conclusions that chain lengths of C₁₄ or C₁₆ gave maximum activity to the aminimide derivative. When a number of hexadecane compounds with different polar groups were compared, the aminimide exhibited wide spectrum antimicrobial activity. Although the functional group was important, the length and character of the acyl chain also help to determine antimicrobial activity. A new amide antibiotic, Cerulenin, with a 4-keto-2-enyl chain, was more active than the unsaturated isomer. Thus, both the functional grup as well as the chain length contribute to biocidal activity.     

α-sulfonated fatty acid esters: II. Solution behavior of α-sulfonated fatty acid polyethylene glycol esters

Sodium α-sulfonated, fatty acid polyethylene glycol monoesters [C _m H_2m+1CH(SO₃Na)COO(C₂H₄O) _n H] and diesters [C _m H_2m+1CH(SO₃Na)COO(C₂H₄O) _n COCH(SO₃Na)C _m H_2m+1], wherem=10–16 andn=1–35, were prepared by esterification of α-sulfonated, fatty acids with polyethylene glycols, followed by neutralization with NaOH. Crude products were purified by reversed-phase column chromatography on an octadecyl-modified silica gel. Characteristic solution behavior of these α-sulfonated fatty acid esters was, examined, and the following features were observed. All monoesters prepared in this work had Krafft points below 0°C and also possessed good calcium stabilities. Critical micelle concentrations of the monoesters increased monotonously, as a rule, with an increase in the number of oxyethylene units. These results suggest that the polyethylene glycol residue of the monoester behaves as a hydrophile. On the other hand, diesters possessed high water solubility, low foamability, and critical micelle concentrations that were lower by a factor of ten compared to those of the monoesters.     

Antimicrobial properties of some erucic acid-glycolic acid derivatives

Twelve fatty acid derivatives of glycolic acid containing erucic acid, or other selected vegetable oil fatty acids, were synthesized. These were screened for antimicrobial activity against a gram-positive bacterium,Staphylococcus aureus; a gram-negative bacterium,Escherichia coli; a mold,Penicillium notatum, and a yeast,Candida utilis. All of the compounds inhibited at least one of these organisms. These compounds were derivatives of glycolic acid prepared by esterification of the carboxyl function of glycolic acid with a long-chain fatty alcohol and reaction of the hydroxyl function of glycolic acid with a long-chain fatty acyl group.     

Gas-liquid chromatography of fatty derivatives. II. Analysis of fatty alcohol mixtures by gas-liquid chromatography

Conclusions Gas-liquid chromatography has been shown to be applicable to the analysis of fatty alcohols. Through the use of polyester columns these alcohols have been separated according to chain length and degree of unsaturation. A study has been made of the relationship between peak areas of the chromatograms and the actual weight percentages of the four C₁₈ alcohols found in the fatty alcohols derived from linseed oil. Fatty alcohols, prepared from soybean, linseed, and sperm oil have been prepared and analyzed by the proposed procedure. Craig and Murty (1) have recently reported that polyesters based on succinic acid are preferable for the liquid phase of the chromatographic column to those made from adipic in that they afford a better separation of methyl stearate from methyl oleate. Conversely adipic columns gave a more effective separation of the esters of linolenic and arachidic acids. The application of these polyesters to the analysis of fatty alcohol acetates is expected to improve their separation in a similar fashion, but further work is indicated in the search for a liquid phase that will permit both separations in the minimum time. ADM Technical Talk No. 166.     

Hydrozirconation for unsaturated fatty acid derivatives

In the hydrozirconation reaction, developed by Schwartz and coworkers,bis(π-cyclopentadienyl) zirconium hydridochloride Cp₂-Zr(H)Cl, is added to the double bond of an olefin. The organozirconium intermediate can be functionalized by reaction with a variety of electrophiles such as oxygen, halogens, acetyl chloride and carbon monoxide. Furthermore, the double bond can be reformed by treatment with a hydride acceptor such as triphenylmethyl tetrafluoroborate. When a short-chain internal olefin is hydrozirconated, the initially formed alkylzirconium intermediate is rapidly isomerized to a compound in which the zirconium moiety is bound to the sterically least hindered position, which most often is the terminal position. The isomerization occurs rapidly at room temperature in contrast to the corresponding organoboron or aluminum compounds, which slowly positionally rearrange only at elevated temperatures. Because of the facile isomerization of internal alkylzirconium compounds to the terminal ones, we investigated application of the reaction to unsaturated fatty acids such as oleic and erucic acids. However, reactions on long-chain alkenes (such as oleic acid) are frequently much slower than those conducted on shorter-chain alkenes, and attention must be given to optimizing the reaction conditions if good yields are to be obtained. It would also be necessary to find an easily removable protecting group for the carboxylic function, as Cp₂Zr(H)Cl reduces carboxylic acids to alcohols. We found that the 4,4-dimethyl-2oxazoline function is a suitable protecting. group, and therefore synthesized the oxazolines from oleic acid and erucic acid. Hydrozirconation of the 4,4-dimethyl-2-oxazoline of oleic acid followed by oxidation witht-butyl hydroperoxide and conversion to methyl esters, gave methyl 3-hydroxy and methyl 18-hydroxy stearate in 13% and 17% yield, respectively. The relatively low yield is due to competing hydrogenation, the mechanism of which is discussed. Recent results indicate that the carboxyl group can be protected ast-butyl esters in the hydrozirconation and that oleyl alcohol derivatives can also be used. To understand the isomerization pattern in hydrozirconation, the reaction with α,β- and β,γ-unsaturated fatty acid oxazolines is discussed. Possibilities of making the hydrozirconation reaction catalytic by binding of the hydrozirconation reagent to a solid support as well as the synthetic potential in combining hydrozirconation with the olefin metathesis reaction are briefly reviewed.     

Recovery of short,medium, and long chain fatty acid methyl esters using wet halogenated hydrocarbons

Fatty acid methyl esters are prepared and analyzed by gas liquid chromatography using a simple procedure that does not involve evaporation steps or drying of the final extract. The esters of fatty acids down to caproate (C₆) are recovered quantitatively. The long chain fatty acid esters, including the polyunsaturated esters, are also recovered quantitatively and are at least as stable as esters isolated by conventional procedures. Preparation of the esters in methanolic reagents is followed by partition of the mixture between a small volume of ethylene chloride and a large volume of water. The lower halogenated hydrocarbon phase contains the methyl esters ready for analysis, and the aqueous phase contains the methanol, catalysts, and other water-soluble materials.