Five corynomycolic acids [2-alkyl-3-hydroxyfatty acid : C_mH_2m+1CH (OH) CH (C_nH_2m+1) COOH] with alkyl chain length (total carbon numbers, 12, 16, 20, 24, and 28) were synthesized and the relation between chemical structure and surface active properties was determined. The unitary acids were synthesized in three steps from ethyl alkanoates with carbon numbers of 6, 8, 10, 12, and 14 as the starting material, respectively : (1) Claisen ester condensation of ethyl alkanoate, (2) selective reduction of C=O to OH by NaBH₄, and (3) hydrolysis of hydroxy ester under alkaline conditions.
Surface tension and interfacial tension toward the decane of aqueous alkaline solution of synthetic corynomycolic acid decreased with increase in its concentration and a well-defined critical micelle concentration (cmc) was not evident in the case of corynomycolic acid from microorganisms was observed. With increase in the length of the alkyl chain, the values of surface and interfacial tension at cmc decreased and became less than that of synthetic surfactants for corynomycolic acid carbon numbers exceeding 16. The surface-active properties of synthetic corynomycolic acid were inferior to those of the corresponding 3-hydroxyfatty acid [C_m+nH_2m+2n+1+CH (OH) CH₂COOH] but superior to those of 3-hydroxyfatty acid whose carboxylic alkyl chain was of the same length [C_mH_2m+1CH (OH) CH₂COOH].

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The geometric and positional isomers of monoenoic, dienoic and trienoic fatty acids were oxidized in aqueous solution using Fe²⁺-ascorbic acid as the catalyst. The oxidative stability of each acid was assessed based on decrease in unoxidized substrate content. The trans and cis isomers of dienoic and trienoic acids were found to differ in stability while this parameter for trans isomers of monoenoic acids was essentially the same as that of the cis isomers. The oxidative stability of monoenoic acid increased with the proximity of olefinic bonds to methyl ends and shortness of chain length. The effect of chain length on oxidative stability was the same for isomers of methylene-interrupted trienoic acids. In aqueous solution, oleic acid was more oxidatively stable than linoleic acid, but oxidized more rapidly than α-linolenic acid. This order for the oxidative stability of unsaturated C₁₈ acids was different from that in air. The relative oxidative stability of nonmethylene-interrupted dienoic and trienoic acids in aqueous solution also differed from that in air.

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The density of liquid and polymorphic crystalline forms of 2-oleoyl-1, 3-dipalmitoylglycerol (POP), 2-oleoyl-1, 3-rac-palmitoyl-stearoylglycerol (POS), and 2-oleoyl-1, 3- distearoylglycerol (SOS) were measured by gas pycnometer. An 0.18 nm³ decrease in molecular volume was observed in all triacylglycerols, corresponding to structural changes in the most stable form of β₁ of the three triacylglycerols. More precisely, the saturated and unsaturated fatty acyl moieties in the triacylglycerols showed no monotonous change in volume.
In sample preparation, density of each polymorphic forms was observed to be highest by symple melt cooling. For melt mediated transformation, and solid state transformation, the values of this parameter were less.

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Calorific values of glyceryl monopalmitate (GMP) during crystallization from ethanol solution containing sorbitan laurate (SL) were determined with a differential scanning calorimeter (DSC). Molecular interactions between GMP and SL in erthanol are discussed. This parameter was taken as the enthalpy change (ΔH) in GMP crystallization. ΔH of GMP crystallization from 0.2 mol/kg of GMP in the absence and presence of SL (0.38 mol/kg) in ethanol was 74 and 62 kJ/mol, respectively. Crystallization temperature in the latter case decreased by about 9°C. The same conditions the apparent activation energy of GMP crystallization was determined from Avrami-Erofe'ev equation. It was found to decreased with increase in SL concentration in GMP solution in ethanol. This consistent with crystallization GMP from ethanol. The results are discussed in relation to findings presented in the previous paper.

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Highly unsaturated triacylglycerols (TAGs) compried of icosapentaenoic (EPA) and docosahexaenoic acids (DHA) were chemically synthesized and assessed for their hydrolyzability toward porcine pancreatic lipase. Triicosapentaenoylglycerol (EEE) and tridocosahexaenoylglycerol (DDD), both unsaturated TAGs, were hydrolyzed to a lesser extent than trilinolenoylglycerol (LnLnLn), trilinoleoylglycerol (LiLiLi) or tripalmitoylglycerol (PPP). The hydrolyzability of synthetic TAGs followed the order, LiLiLi>LnLnLn>PPP>>DDD>EEE. EEE was the most resistant to pancreatic lipase hydrolysis.

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New betaine types of amphoteric surfactants each bearing a 1, 3-dioxolane ring were prepared by reaction of epibromohydrin and ethyl levulinate in the presence of BF₃·Et₂O, followed by treating the products thus obtained with N, N-dimethyl (long-chain alkyl) amines and then neutralization. Surface-active properties in neutral aqueous solution, decomposition profiles under acidic conditions and properties of the aqueous solutions following decomposition were clarified.

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