Oleic acids

Definite evidence has recently been found that oleic acid plays a part in the growth requirements of several micro-organisms. Fleming in 1909 (94) observed that the acne bacillus (Corynebacterium acnes), which is difficult to cultivate, grew best in ordinary nutrient agar to which 1-5% oleic acid was added. 

This generally occurs in the form of glycerides in olive, almond, cotton and sunflower oils. Oleic acid is a colorless, tasteless and odorless liquid with a melting point of 13 °C. It forms one third of the total fatty acids in cow s milk and is used in the production of lubricants, detergents, resins and other products. Stearic acid is formed by the addition of hydrogen to oleic acid. 

Molecular formula C18H34O2 Molecular weight 282.46 CAS Registry No 112-80-1 Merck Index 13, 6898 

Sample preparation Mix 10 [xL plasma with 200 XL 40 xg/mL IS in EtOH and 90 p.L Eton, add 100 pL 2 M KOH in EtOHiwater 50 50, heat at 80° for 20 min, cool to room temperature. Add 200 pL 20 mM 2-nitrophenylhydrazine in 300 mM HChEtOH 50 50, add 200 pL 250 mM l-ethyl-3-(3-dimethylaminopropyl)carhodiimide hydrochloride in EtOH pyridine 97 3, heat at 80° for 5 min. Cool the solution to room temperature, add 10% KOH in MeOH water 50 50, heat again at 80° for 5 min, cool to room temperature. Add 4 mL 33 mM pH 4.6 potassium phosphate hufifer 500 mM HCl 70 10, extract with 4 mL hexane by shaking vigorously for 2 min. Centrifuge at 20 000 rpm for 10 min, evaporate the upper layer under a stream of nitrogen, resuspend the residue in 400 pL MeOH, inject a 50 pL aliquot. 

Mobile phase Gradient. A was MeCN. B was MeCN MeOH water 75 11 14. A B 0 100 for 20 min, from 0 100 to 100 0 over 5 min, maintain at 100 0 for 10 min, return to initial conditions over for 2 min, re-equUibrate. 

Extracted arachidonic acid (14.5), docosanoic acid (38), eicosanoic acid (34), eicosatrienoic acid (17), eicosapentanoic acid (12), lauric acid (10), Unoleic acid (15.5), linolenic acid (12.5), gamma-linolenic acid (13), m5rristic acid (13), palmitic acid (18.5), patmitoleic acid (15), stearic acid (27), tetracosanoic acid (42) 

Bsiiley, A.L. Southon, S. Determination of total long-chain fatty acids in human plasma and hpopro-teins, before and during copper-stimulated oxidation, by high-performance hquid chromatography, Anal.Chem., 1998, 70, 415-419. 

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HOOO(CH2)7COOH. Colourless plates, m.p. lOfi C. Made by the oxidation of oleic acid with ozones. 

The oleic acid series, C H2n-202 with one double bond, of which acrylic acid is the lowest member. 

HOOC-[CHa]8-COOH, CioH.aO. Colourless leaflets m.p. 134°C. Manufactured by heating castor oil with alkalis or by distillation of oleic acid. Forms an anhydride, m.p. 78 C. The esters of sebacic acid are used as plasticizers, especially for vinyl resins. 

SNG Substitute natural gas. soaps Sodium and potassium salts of fatty acids, particularly stearic, palmitic and oleic acids. Animal and vegetable oils and fats, from which soaps are prepared, consist essentially of the glyceryl esters of these acids. In soap manufacture the oil or fat is heated with dilute NaOH (less frequently KOH) solution in large vats. When hydrolysis is complete the soap is salted out , or precipitated from solution by addition of NaCl. The soap is then treated, as required, with perfumes, etc. and made into tablets. 

C8Hi7CH=CH(CH2)7COOH Oleic acid c/s-9-Octadecenoic acid... 

Spreading velocities v are on the order of 15-30 cm/sec on water [39], and v for a homologous series tends to vary linearly with the equilibrium film pressure, it", although in the case of alcohols a minimum seemed to be required for v to be appreciable. Also, as illustrated in Fig. IV-3, substrate water is entrained to some depth (0.5 mm in the case of oleic acid), a compensating counterflow being present at greater depths [40]. Related to this is the observation that v tends to vary inversely with substrate viscosity [41-43]. An analysis of the stress-strain situation led to the equation... 

Fig. IV-3. Velocity profiles for particles suspended in water with elapsed time, due to spreading of oleic acid. Time after onset of spreading O, 5 sec, , 5 sec. (From Ref. 31.)...

Absorption spectroscopy provides a means to study particular details about a monolayer. Transmission spectroscopy is difficult because the film, which is thin, absorbs little. Gaines [1] describes multiple-pass procedures for overcoming this problem. Reflection spectroscopy in the UV-visible range has been reported for lipid monolayers [150,151] and in the IR range for oleic acid [152]. 

Rehbinder and co-workers were pioneers in the study of environmental effects on the strength of solids [144], As discussed by Frumkin and others [143-145], the measured hardness of a metal immersed in an electrolyte solution varies with applied potential in the manner of an electrocapillary curve (see Section V-7). A dramatic demonstration of this so-called Rehbinder effect is the easy deformation of single crystals of tin and of zinc if the surface is coated with an oleic acid monolayer [144]. 

It is quite clear, first of all, that since emulsions present a large interfacial area, any reduction in interfacial tension must reduce the driving force toward coalescence and should promote stability. We have here, then, a simple thermodynamic basis for the role of emulsifying agents. Harkins [17] mentions, as an example, the case of the system paraffin oil-water. With pure liquids, the inter-facial tension was 41 dyn/cm, and this was reduced to 31 dyn/cm on making the aqueous phase 0.00 IM in oleic acid, under which conditions a reasonably stable emulsion could be formed. On neutralization by 0.001 M sodium hydroxide, the interfacial tension fell to 7.2 dyn/cm, and if also made O.OOIM in sodium chloride, it became less than 0.01 dyn/cm. With olive oil in place of the paraffin oil, the final interfacial tension was 0.002 dyn/cm. These last systems emulsified spontaneously—that is, on combining the oil and water phases, no agitation was needed for emulsification to occur. 

Among the many applications of LB films, the creation or arrangement of colloidal particles in these films is a unique one. On one hand, colloidal particles such as 10-nm silver sols stabilized by oleic acid can be spread at the air-water interface and LB deposited to create unique optical and electrooptical properties for devices [185]. 

The term fat is applied to solid esters of fatty acids with glycerol (glycerides) if the fat is liquid at the ordinary temperature, it is conventionally called a fatty oil, vegetable oil or animal oil. The acids which occur most abundantly are palmitic ticid CH3(CHj),4COOH, stearic acid CH3(CH2)isCOOH and oleic acid CH3(CH2),CH=CH(CH2),C00H. Upon hydrolysis, fats yield glycerol and the alkali salts of these acids (soaps) ... 

Dissolve 7 g. of pure oleic acid in 30 ml. of dry ethyl chloride (chloroform may be used but is less satisfactory), and ozonise at about —30°. Remove the solvent under reduced pressure, dissolve the residue in 50 ml. of dry methyl alcohol and hydrogenate as for adipic dialdehyde in the presence of 0 5 g. of palladium - calcium carbonate. Warm the resulting solution for 30 minutes with a slight excess of semicarbazide acetate and pour into water. Collect the precipitated semicarbazones and dry the... 

When the groups on either end of a double bond are the same or aie shuctuially sum lar to each other it is a simple matter to describe the configuration of the double bond as CIS or trans Oleic acid for example a compound that can be obtained from olive oil has a CIS double bond Cmnamaldehyde responsible for the characteristic odor of cm namon has a trans double bond... 

Multiply unsaturated linolenic and linoleic acid residues make triglycerides more vulnerable to oxidative degradation than oleic acid which is relatively stable. It is therefore desirable to hydrogenate the most unsaturated residues selectively without production of large quantities of stearic (fully saturated) acid. The stepwise reduction of an unsaturated oil may be visualized as ... 

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