The alcoholysis of crambe and camelina oils was carried out with oleyl alcohol, alcohols derived from crambe and camelina oils, and n-octanol using potassium hydroxide as catalyst to prepare alkyl esters. Conversions to alkyl esters were about 70% with oleyl alcohol, 20-45% with crambe and camelina alcohols, and 60% with n-octanol. The conversion to esters for crambe and camelina oil with oleyl alcohol and n-octanol increased with increasing molar excess of alcohol. Composition of the alkyl esters formed was as expected from the composition of the reaction partners.Crambe (Crambe abyssinica) and camelina (Camelina sativa) are less investigated oil plants, whose cultivation on poor nutrient soils is expected to be successful. These oil plants are regarded as industrial resources for different oleochemical applications because crambe oil is a rich source (1,2) of erucic acid (cis-13-docosenoic acid; ca. 56%), and camelina oil is a source (3) of α-linolenic acid (all-cis-9,12,15-octadecatrienoic acid; ca. 38%).The objective of the present work was to prepare alkyl esters of crambe and camelina oils that may have useful applications in lubricants and cosmetics. Transesterification (alcoholysis) of triacylglycerols with alcohols catalyzed by alkali (4-7) or acid catalysts (8,9) is well known and often used for the preparation of alkyl esters. We report here the potassium hydroxide-catalyzed alcoholysis of crambe and camelina oils with long-chain alcohols, such as oleyl alcohol and alcohols derived from crambe and camelina oils, for the preparation of mixtures of long-chain and very long chain wax esters resembling those of jojoba oil. Although the main chain lengths of the expected wax esters are C40 and C44, these esters may be useful as surrogates for jojoba (Simmondsia chinensis) wax esters, which have a main chain length of 42 carbon atoms (ca. 50% of the wax esters) (10,11). Jojoba wax is used in cosmetics, pharmaceuticals, and in the food industry because of its practically unchanged viscosity over a wide range of temperatures (12). Owing to the high price of the final product (inability to economically cultivate the plants) it is desirable to find a low-cost jojoba oil substitute (13). We also report the alkalicatalyzed alcoholysis of crambe and camelina oils with n-octanol and isopropanol. The goal was to obtain products similar to enzymatically prepared medium-chain and short-chain esters (14) with properties suitable for applications in cosmetics. EXPERIMENTAL PROCEDURESMaterials. Crambe and camelina were grown in experimental fields. The seeds and refined oils were supplied by the Institut für Pflanzenbau der Landesforschungsanstalt für Landwirtschaft und Fischerei Mecklenburg-Vorpommern (Gülzow, Germany). Fatty acid composition of the oils (designated by number of carbon atoms:number of cis-double bonds) was as follows. Crambe oil: 16:0 = 2%, 18:0 = 1%, 18:1 = 17%, 18:2 = 9%, 18:3 = 6%, 20:0 = 1%, 20:1 = 4%, 22:0 = 2%, 22:1 = 56%, 24:1 = 1%; camelina oil: 16:0 = 5%, 18:0 = 3%, 18:1 = 14%, 18:2 = 16%, 18:3 ...

Earlier feeding studies of rats revealed that petroselinic acid [18:1(n-12)] from triacylglycerols of coriander (Coriandrum sativum) oil is extensively incorporated into the lipids of heart and liver and metabolized via beta-oxidation and chain elongation. We report here the composition and stereospecific distribution of acyl moieties, particularly isomeric octadecenoyl moieties, in adipose tissue triacylglycerols of male weaned Wistar rats fed diets containing, in addition to 20 g corn oil/kg feed, 120 g coriander oil per kg feed at a level of 63 g 18:1(n-12) moieties/100 g acyl moieties of the oil for 10 wk. For comparison, a group of rats was fed a similar corn oil-containing isocaloric diet with large proportions of oleoyl moieties [18:1(n-9)] from high oleic sunflower oil [72 g 18:1(n-9)/100 g acyl moieties of the oil]. The composition of the triacylglycerols of epididymal, subcutaneous and perirenal adipose tissues was very similar for each feeding group, broadly reflecting the composition of the dietary oils. Feeding coriander oil, compared with high oleic sunflower oil, led to extensive incorporation of 18:1(n-12) into the triacylglycerols of the adipose tissues with a concomitant significantly and dramatically lower 18:1(n-9) concentration and, as a consequence, to the generation of triacylglycerol species containing 18:1(n-12) moieties. Petroselinoyl moieties from coriander oil were esterified predominantly at the sn-1,3 positions of the adipose tissue triacylglycerols; 18:1(n-9) moieties from high oleic sunflower oil were fairly evenly distributed between the sn-1,3 and sn-2 positions. We suggest that acyltransferases involved in the biosynthesis of adipose tissue triacylglycerols direct 18:1(n-12) moieties preferentially to sn-1,3-positions.

A method has been developed for the preparation of highly pure malvalic (cis-8,9-methyleneheptadec-8-enoic) and sterculic (cis-9,10-methyleneoctadec-9-enoic) acid methyl esters starting from Bombax munguba and Sterculia foetida seed oils. The methyl esters of these oils were prepared by sodium methylate-catalyzed transmethylation followed by cooling (6°C) the hexane solution of crude methyl esters and separation of insoluble fatty acid methyl esters by centrifugation in the case of B. munguba and by column chromatography in the case of S. foetida. Subsequently, the saturated straightchain fatty acid methyl esters were almost quantitatively removed by urea adduct formation. Finally, methyl malvalate and methyl sterculate were separated from the remaining unsaturated fatty acid methyl esters, in particular methyl oleate and methyl linoleate, by preparative high-performance liquid chromatography on C 18 reversed-phase using acetonitrile isocratically. Methyl malvalate and methyl sterculate were obtained with purities of 95-97 and 95-98%, respectively. JAOCS 75, 1757-1760 (1998). KEY WORDS:Bombax munguba oil, cyclopropene fatty acids, malvalic acid methyl ester, preparative HPLC, Sterculia foetida oil, sterculic acid methyl ester, urea fractionation.Cyclopropene fatty acids are widely distributed in the seed oils of many plant families of the order Malvales (1,2). Small proportions of cyclopropene fatty acids, e.g., malvalic (cis-8,9-methyleneheptadec-8-enoic) and sterculic (cis-9,10-methyleneoctadec-9-enoic) acids, which are present in crude cottonseed oil, are of special interest owing to their harmful biological effects when fed to animals (3-7).The presence of cyclopropene fatty acids in seed oils can be roughly checked by the Halphen test (8). Identification by gas chromatography (GC) and high-performance liquid chromatography (HPLC) analysis (9,10) is difficult, however, because no cyclopropene fatty acid standards are commercially available. This paper presents a simple method for the preparation of both methyl malvalate and methyl sterculate of high purity, which may be useful for GC and HPLC comparison as well as biochemical and enzymatic studies. The starting materials were seeds of Bombax munguba (11) and Sterculia foetida (1,2), which are known to be good sources of cyclopropene fatty acids. EXPERIMENTAL PROCEDURESMaterials. Distilled solvents were used throughout. HPLCgrade acetonitrile was purchased from Rathburn Chemicals (Walkerburn, Scotland). Silica gel, urea, and sodium methylate were products of E. Merck (Darmstadt, Germany). Bombax munguba Mart. seeds were collected at University of Paraiba, João Pessoa, Brazil (11); S. foetida L. seeds were a gift from Professor Helmut K. Mangold, Münster, Germany.Preparation of fatty acid methyl esters (FAME). Seeds of B. munguba (10 g) were ground in an electric coffee grinder and the meal extracted in a Soxhlet extractor for 6 h with 200 mL hexane. The hexane was evaporated and the oil transmethylated with sodium methylate in methanol (11). After addition of...