M. O. Bagby

A novel compound, 7,10-dihydroxy-8(E)-octadecenoic acid from oleic acid by bioconversion

Sixty-two cultures from the Agricultural Research Service (ARS) Culture Collection and 10 cultures isolated from soil and water samples in Illinois were screened for their ability to convert agricultural oils to value-added industrial chemicals. A new compound, 7,10-dihydroxy-8(E)-octadecenoic acid (DOD), was produced from oleic acid at a yield of greater than 60% by bacterial strain PR3 which was isolated from a water sample in Morton, IL. To our knowledge, DOD has not been previously reported. The optimum time, pH and temperature for the production of DOD were 2 days, 7.0, and 30°C, respectively. The production of DOD is unique in that it involves hydroxylation at two positions and rearrangement of the double bond of the substrate molecule.

Heats of combustion of fatty esters and triglycerides

Gross heats of combustion (HG) have been measured for three classes of fatty esters and two classes of triglycerides (TGs). The esters included saturated methyl esters, Me 6:0–22:0; saturated ethyl esters, Et 8:0–22:0; and unsaturated methyl esters, Me 12:1–22:1, Me 18:2 and Me 18:3. The TGs included the saturated TGs, C 8:0–22:0, and unsaturated TGs, C 11:1, C 16:1, C 18:1, C 18:2, C 18:3, C 20:1 and C 22:1. HG were measured in a Parr adiabatic calorimeter according to a modification of ASTM D240 and D2015. Linear regression analysis (LINREG) yielded equations that related HG to carbon number (CN) or chain length, electron number (EN) or number of valence electrons and molecular weight (MW). Calculated HG values from CN, EN, or MW were nearly identical. Thus, any one of these three variables can be used to predict HG satisfactorily. R squared values for all equations were 0.99. Equations for correlating HG of saturated or unsaturated TGs with molecular characteristics of these molecules have not been reported. With LINREG, we developed equations that permitted predictions of HG from structures of the saturated and unsaturated TGs. Equations for predicting HG of methyl and ethyl esters were compared to those in the literature and were found to be more accurate and precise.

Predicting Cetane Numbers of n-Alcohols and Methyl Esters from their Physical Properties

Cetane numbers (C#) for the homologous series of straight-chain, saturated n-alcohols, C5−C12 and C14, were determined according to ASTM D 613. Measured C# ranged from 18.2–80.8 and increased linearly with carbon number (CN). Regression analyses developed equations that related various physical properties or molecular characteristics of these alcohols to calculated C#. The degree of relationship between measured and calculated C# was expressed as R2. The decreasing order of the precision with which these properties correlated with C# was: boiling point (bp)>melting point (mp)>CN>heat of combustion (HG)>refractive index (n20D)>density (d). This ranking was based upon R2 (0.99–0.96) and the Average % error (2.8–7.2%). C# were also determined for straight-chain homologs of saturated methyl esters with CN of 6, 10, 12, 14, 16 and 18. C# ranged from 18.0–75.6 and increased curvilinearly with CN. Equations were also developed that related physical properties of these esters to C#. The precision with which these properties correlated with C# was: bp>viscosity (V)>heat of vaporization (HV)>HG>CN>surface tension (ST)>mp>n20D>d. R2 ranged from 0.99 for bp to 0.98 for d. Equations for the alcohols were linear or quadratic, while equations for the esters were linear, quadratic or cubic based upon statistical considerations that included a Student’s t-test. With related physical properties and these equations, accurate predictions of C# can be made for saturated n-alcohols and methyl esters.

Production of a new compound, 7,10-dihydroxy-8-(E)-octadecenoic acid from oleic acid byPseudomonas sp. PR3

SummarySixty-two cultures from the ARS Culture Collection and 10 cultures isolated from soil and water samples collected in Illinois were screened for their ability to convert agricultural oils to value-added industrial chemicals. A new compound, 7,10-dihydroxy-8-(E)-octadecenoic acid (DOD) was produced from oleic acid by a new strain,Pseudomonas sp. PR3 isolated from a water sample in Morton, IL. Strain PR3 is a motile, small rod-shaped, Gram-negative bacterium. It has multiple polar flagellae and is oxidase-positive. Strain PR3 grows aerobically and cannot grow anaerobically. The strain produces white, smooth colonies on agar plate and no water-soluble pigment. The yield of the product was greater than 60%. The optimum time, pH and temperature for the production of DOD were: 2 days, 7.0, and 30°C, respectively. Glycerol and dextrose support the growth of strain PR3, but the cells grown from the former failed to catalyse the conversion of oleic acid to DOD. The production of DOD is unique in that it involves a hydroxylation at two positions and a rearrangement of the double bond of the substrate molecule.

Polymerization of vegetable oils and their uses in printing inks

Ink vehicles were prepared by the polymerization of vegetable oils. By controlling the polymerization conditions, the desired viscosity, color and molecular weight could be achieved for a variety of vegetable oils with a broad range of iodine values and fatty acid compositions. The effect of temperature and catalyst on polymerization rates were evaluated, and polymerization rate constants were calculated. Of the oils tested, the polymerization rate constant of safflower oil was the highest, followed by soybean, sunflower, cottonseed and canola oils in decreasing order. Use of a catalyst shortened the heating time by about 25–50% or lowered the polymerization temperature requirement by 25–30°C.

Analysis of oil and meal fromLesquerella fendleri seed

Attention is being focused onLesquerella species as a source of hydroxy acids to replace imported castor oil. Genetic and agronomic improvement and utilization of the seed oil and meal are being studies. We have conducted laboratory experiments to extract oil fromL. fendleri seed in preparation for extracting large quantities of seed.L. fendleri is a member of the Cruciferae family, and when seeds are crushed glucosinolates release isothiocyanates by the action of a thioglucosidase enzyme system. Therefore, our experiments included moist heat treatment of whole seeds to inactivate this enzyme. The seed was then flaked in a Wolf mill, and the flakes were exhaustively extracted with hexane. The oil was degummed and bleached, and then analyzed for hydroxyl (103), saponification (174), and iodine values (107), and for unsaponifiables (1.5%), FFA (1.13%) and P (10 ppm) contents. Hydroxy fatty acids, 55% lesquerolic (14-hydroxy-cis-11-eicosenoic) and 3% auricolic (14-hydroxy-cis-11,cis-17-eicosadienoic), and total fatty acid distribution were determined by gas chromatography of the methyl esters. The defatted meal was analyzed for residual oil (1%), protein (29.8%), non-protein nitrogen (0.7%), ash (6.45%). crude fiber (12.9%), and for distribution of amino acids. DefattedL. fendleri meal has an excellent distribution of amino acids, including favorable levels of lysine, methionine and threonine compared with soybean meal.

Epoxidation ofLesquerella andLimnanthes (Meadowfoam) oils

Lesquerella gordonii (Gray) Wats andLimnanthes alba Benth. (Meadowfoam) are species being studied as new and alternative crops. Triglyceride oil from lesquerella contains 55–60% of the uncommon 14-hydroxy-cis-11-eicosenoic acid. Meadowfoam oil has 95% uncommon acids, includingca. 60%cis-5-eicosenoic acid. Both oils are predominantly unsaturated (3% saturated acids), and have similar iodine values (90–91), from which oxirane values of 5.7% are possible for the fully epoxidized oils. Each oil was epoxidized withm-chloro-peroxybenzoic acid, and oxirane values were 5.0% (lesquerella) and 5.2% (meadowfoam). The epoxy acid composition of each product was examined by gas chromatography of the methyl esters, which showed that epoxidizedL. gordonii oil contained 55% 11,12-epoxy-14-hydroxyeicosanoic acid, and epoxidized meadowfoam oil contained 63% 5,6-epoxyeicosanoic acid, as expected for normal complete epoxidation. Mass spectrometry of trimethylsilyloxy derivatives of polyols, prepared from the epoxidized esters, confirmed the identity of the epoxidation products and the straightforward nature of the epoxidation process. Synthesis and characterization of these interesting epoxy oils and derivatives are discussed.

Preparative chromatographic isolation of hydroxy acids fromLesquerella fendleri andL. gordonii seed oils

To conduct product development research onLesquerella seed oils, we explored methods to obtain >100 g quantities of lesquerolic (14-hydroxy-cis-11-eicosenoic) acid. Preliminary experiments with open-column silica gel chromatography showed thatL. fendleri oil could be separated into 3 triglyceride (TG) fractions. The first (10%) contained nonhydroxy 16-(13%) and 18-carbon acids (65% 18∶1,2,3). The second fraction (15%) contained monolesquerolins (39% lesquerolic acid). The major TG fraction (73%) was mainly dilesquerolins (66% lesquerolic acid) showing that a hydroxy acid-enriched TG oil was obtainable by this procedure. Silica gel chromatography easily separatedL. fendleri fatty acid methyl esters (FAME) into a hydroxy-free ester fraction (40–44%) consisting largely of 18∶1 (39%), 18∶2 (19%) and 18∶3 (31%), and a hydroxy ester fraction (56–60%) that was largely methyl lesquerolate (94%) with small amounts of auricolate (5%) (14-hydroxy-cis-11,cis-17-eicosadienoate) and traces of 18-carbon hydroxy esters. This process for isolating the hydroxy FAME ofLesquerella oil was scaled up 15-to 100-fold with a preparative high performance liquid chromatograph. Thirty-gram samples ofL. gordonii FAME were dissolved in eluting solvent, pumped onto the high performance liquid chromatography (HPLC) silica column and eluted with 97∶3 hexane/ethyl acetate. In an 8-hr period, up to 200 g of methyl lesquerolate could be obtained with a purity >98%, the only contaminants being methyl auricolate and methyl ricinoleate.

Solid state analysis of plant polymers by FTIR

Abstract Wheat straw, kenaf, oak, and pine were extracted to give samples with various contents of lignin, hemicellulose, and cellulose. Precise amounts of these samples were blended with KBr and pressed into discs, and their FTIR spectra were determined. Two-spectra subtraction, and combination of multiple spectra by matrix inversion and least squares matrix methods were used to give spectra of individual lignin, hemicellulose, and cellulose components in all 4 plant types. They are the most complete IR spectra available for lignin in plant matrices.

Correlation of heats of combustion with empirical formulas for fatty alcohols

Gross heats of combustion (Hg) for the homologous series of saturated fatty alcohols C10–C22 were measured in a Parr adiabatic calorimeter according to ASTM D240 and D2015. The measured values for these alcohols ranged from 1582 to 3453 kg-cal/mole. We developed equations that related carbon number (CN) or chain length, electron number (EN) or number of valence electrons and molecular weight (MW) to calculated Hg by linear regression analysis (LINREG). These equations are: Hg=26.00+155.60 CN; Hg=26.00+25.94 EN; and Hg=−172.2+11.00 MW. R squared values for all three equations were 0.99. The results obtained with LINREG were compared to a literature method. Comparisons were made for both the fatty alcohols above and C1–C5, C7, C8 and C16 alcohols of the literature method. For the former alcohols there was no difference in accuracy or precision between the two methods. For the latter alcohols LINREG was both more accurate and precise. Measured Hg vs. chain length for C1–C22 alcohols showed a perfect linear relationship. Thus, knowing chain length, Hg can be predicted accurately for alcohols in this range.