bluuebunny/crossref_metadata_2025_split huggingface dataset:
Hydrozirconation for unsaturated fatty acid derivatives
Authors: Alvhäll J. , Gronowitz S. , Hallberg A. , Svenson R. 
Published: July 2007

AbstractIn 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.
Microbial conversions of alkanes and fatty acids
Authors: Ratledge Colin 
Published: July 2007

AbstractAlkanes are attacked readily by a wide variety of microorganisms. The most frequently encountered mode of oxidation is for one of the terminal methyl groups to be oxidized, through the alkanol, then the alkanal, to the corresponding fatty acid. Alkanes may be attacked subterminally also, and various ketones as well as the corresponding secondary alcohols can be produced. Subsequent degradation of these ketones occurs via introduction of oxygen into the chain to give a corresponding ester, which is then hydrolyzed to give a primary alkanol 2 carbon atoms shorter than the original alkane. The fatty acids arising by either route of oxidation, or by gratuitous introduction to the microbial system, may be oxidized by: (a) β‐oxidation to give a number of acetyl‐CoA units—intermediates of the process cannot be isolated from this pathway due to the tightly coupled nature of the substrates to the enzymes; (b) α‐oxidation; or (c) oxidation at the other end of the molecule. In the latter case, ω‐ and ω—1‐hydroxyfatty acids can be produced. ω‐Hydroxyfatty acids are subsequently oxidized to give dicarboxylic acids, which can be isolated, sometimes in high yield, by use of appropriate microbial mutants lacking in certain of the key metabolizing enzymes. With some yeasts, the fatty acids, including the ω‐hydroxyfatty acids, can be esterified to various sugars to give a series of glycolipids. In some cases, wax esters are formed between fatty acid and alkanol; these wax esters can include diunsaturated molecules having a close chemical similarity to those of sperm whale and jojoba oils. Various recent innovations have occurred using isolated enzyme systems which can be used in transesterification reactions to convert cheap triacylglycerols into high value added commodities such as cocoa butter.
Nutritional properties of medium‐chain triglycerides
Authors: Kaunitz Hans , Johnson Ruth Ellen 
Published: July 2007

AbstractThe biological effects of MCT (medium‐chain triglycerides) differed from those of conventional fats, and certain of these suggested examination of the fatty acid composition and triglyceride structure of the adipose tissues and other organs of rats which were fed medium‐ or long‐chain triglyceride mixtures with two levels of linoleic acid. Fatty acid compositions and TG patterns varied with the tissue, with the dietary fat, and with the level of linoleate in the diet. Increasing the latter resulted in the deposition of more linoleate at the expense of oleate and in the deposition of more of the dietary fatty acids. The percentage of completely saturated triglyc‐erides (S3), in adipose tissue with the higher linoleate supplement in the rats fed MCT, decreased in those fed LCT and was unchanged in the controls fed a fat‐free diet. The increased deposition of the dietary fatty acids was more pronounced in the S3 band.
Medium‐chain triglycerides—their composition, preparation, and application
Authors: Babayan V. K. 
Published: July 2007

AbstractMedium‐chain triglycerides, prepared from fractionated fatty acids of vegetable oils ranging from caproic to lauric, have been prepared and used in the treatment of patients suffering from malabsorption syndromes. Commercial practices for processing of the kernel oils to obtain such fractionation of fatty acids are described, and the practical sources for such medium‐chain fatty acids are given. Medium‐chain esters of synthetic fatty acids and modifications of such esters for special medicinal and nutritional uses are suggested for future consideration and application.
Nutritional evaluation of medium‐chain triglycerides in the rat
Authors: Harkins Robert W. , Sarett Herbert P. 
Published: July 2007

AbstractNutritional evaluation of a medium‐chain triglyceride (MCT) preparation, containing about 75% octanoic acid and 25% decanoic acid, was carried out in short‐ and long‐term experiments in rats. A casein diet containing 19.6% MCT and 2.5% safflower oil, the latter to supply essential fatty acids, was compared with similar diets containing conventional dietary fats. Data obtained in a 47‐week study showed that the MCT diet supported normal growth and development. At autopsy, carcass protein and ash levels, vital organ weights and composition were similar to those in rats fed conventional fats. Histological study showed that intestinal and liver sections were normal after 47 weeks on the MCT‐containing diet. In general, rats fed MCT had slightly lower growth rates and caloric efficiency values, less carcass fat and smaller epididymal fat pads than animals fed conventional dietary fats. Little C8 and C10 were found in depot fat. The MCT diet also supported normal reproducton, as indicated by litter size and number. During lactation the volume of milk secreted by the rats receiving the MCT diet was smaller and contained a lower level of fat than that secreted by the rats receiving an oleo oil diet, resulting in slower gains in weight in the MCT group. After weaning, growth of the rats fed MCT compared favorably with that attained by the animals on the diet containing oleo oil.
Distribution modes and possible origins of sheep wool hydrocarbons
Authors: Simmonds P. G. , Nooner D. W. , Zlatkis A. , Oro J. 
Published: July 2007

AbstractAn unusual mode of distribution of low‐molecular‐weight n‐alkanes (C11‐C15) with a slight even carbon‐number predominance has been observed in the gas Chromatographic analysis of the paraffin fraction which was extracted from the wool of live sheep. This is in addition to the other two modes of medium‐, C15‐C24, and high‐, C24‐C33, molecular‐weight alkanes usually present in wool wax which have also been found in sheep's manure. The high‐molecular‐weight hydrocarbons (predominantly odd carbon‐numbered) are presumed to be derived from the diet (pasture plants) whereas the other two hydrocarbon distributions probably result from the combined action of animal and microbial metabolism.
Whiteness and fluorescence of fabrics
Authors: Nieuwenhuis K. J. 
Published: July 2007

AbstractA method was devised for measuring the whiteness of fabrics containing optical brighteners. It is simple in operation and gives excellent agreement with the visual appraisal by 27 observers of the whiteness for fabrics with different values for their fluorescence, lightness, yellowness or blueness, and redness or greenness. The fabrics contained different quantities of various blues and optical brighteners.Apart from duplicates it requires only four measurements for each surface, viz., lightness, tristimulus amber and blue reflectance, and the tristimulus blue part of the fluorescent light. Yellowness or blueness, redness or greenness, fluorescence effect on the whiteness, whiteness without fluorescence, and whiteness including fluorescence are calculated from the measurements.The method also indicates which fabrics cannot be called “near white” because they are too gray or too strongly colored. It can be adapted to different compositions of the incident light with regard to the relative intensity of the ultraviolet and visible portions.
Evaluation method for agglomerating properties of granular detergents
Authors: Nagai Toshio , Onzuka Hiromu 
Published: July 2007

AbstractA new method for evaluating the agglomerating property of granular detergents was devised. It is useful for comparing commercial products, screening new products, and for studying anticaking agents. This method differs from prior methods, as detergent is fluidized by conditioned air in a reverse conical tower, and agglomeration is evaluated from the lowering of level of fluidized particles because of agglomeration. The height of the fluidized particles is inversely proportional to particle size, and the level of fluidized particles becomes lower more rapidly with ease of agglomeration. The coefficient of variation (σ/−x) of the method is about 10%, and it is shown that the method coincides with the tendency of detergents to agglomerate in the carton.
Crambe seed processing. improved feed meal by soda ash treatment
Authors: Mustakas G. C. , Kirk L. D. , Griffin E. L. , Clanton D. C. 
Published: July 2007

AbstractCrambe seed, like rapeseed, is characterized by having thioglucosides and perhaps other antigrowth factors that diminish feed value and palatability. A soda ash cooking process was developed that modifies the thioglucosides in crambe meal and significantly improves its feeding value. Destruction of the undesirable thioglucoside fraction of the meal was demonstrated, not only by paper Chromatographic changes but also by negative results in tests which were based on conversion of the thioglucoside to thiooxazolidone. Sodium carbonate, added at a level of 1.4% (whole seed basis), destroys both the goitrin precursor,epi‐progoitrin thioglucoside, and the ultraviolet‐absorbing compounds in the meal, at least one of which is associated with bitterness. Animal‐feeding tests demonstrated the improved palatability and nutritional quality of the meal.
Beta‐Amines
Authors: McCorkle Miles R. , DuBrow Paul L. , Marsh Byron E. 
Published: July 2007

AbstractPetroleum‐based olefins are the source of a new series of alkylated amines. These constitute a series of more liquid, more soluble secondary alkyl primary amines and assorted cationic derivatives. Isomer distribution, physical property and application data are presented.
Synthesis ofcis 9, 15‐, 8, 15‐, and 7, 15‐octadecadienoic acid
Authors: Stroink J. B. A. , Sparreboom S. 
Published: July 2007

AbstractIn connection with the study of autoxidation of someiso‐linoleic acids, the 9,15‐, 8,15‐, and 7,15‐octadecadienoic acids have been synthesized by partial hydrogenation of the corresponding diynoic acids. These acids were prepared by coupling ३‐iodo‐3‐alkynes with ३‐chloro‐1‐alkynes by means of sodium amide in liquid ammonia to form ३‐chlorohexadiynes, followed by condensation of the corresponding iodine compounds with sodium malonic ester.
Thin‐layer chromatographic determination of antioxidants by the stable free radical ॅ, ॅ′‐diphenyl‐ॆ‐picrylhydrazyl
Authors: Glavind J. , Holmer G. 
Published: July 2007

AbstractThe reaction between the stable free radical ॅ,ॅ′‐diphenyl‐ॆ‐picrylhydrazyl (DPPH) and antioxidants can be used for the visualization of antioxidants in thin‐layer chromatography. Amounts of tocopherols down to 0.5 ॖg can be detected. The identification of tocopherols in oils and other natural products and of synthetic antioxidants, added to lard, are described. Saponification is not required. Quantitative analyses of े‐tocopherol give satisfactory results.
Iso‐linoleic acids responsible for the formation of the hardening flavor
Authors: Keppler J. G. , Horikx M. M. , Meijboom P. W. , Feenstra W. H. 
Published: July 2007

AbstractThe hardening flavor that develops in hydrogenated linseed oil and soybean oils during storage was recently identified as 6‐nonenal. According to the theory of Farmer, certainiso‐linoleic acids must be the precursors of this unsaturated aldehyde. By means of oxidation experiments on 9,15‐, 8,15‐, and 7,15‐iso‐linoleic acids, it was established that only the first twoiso‐acids are the precursors of this typical flavor.
Interesterification products and processes
Authors: Going Louis H. 
Published: July 2007

AbstractInteresterification as applied to fats and oils is a process whereby the fatty, acid moieties of glyceride molecules are rearranged in a random or directed manner. Either type of rearrangement may involve production of new triglyceride compositions in a predictable manner. A number of patented processes for accomplishing interesterification are discussed. Effective rearrangement catalysts are listed. Typical applications to commercial products are reviewed.
Minicolumn chromatography: State of the art
Authors: Holaday C. E. 
Published: July 2007

AbstractIt was recognized in the early 1960s that a rapid screening method for aflatoxin was needed. Holaday first proposed the minicolumn chromatography method as a rapid screening method in 1968. Since that time, many improvements have been made in this method. The latest minicolumn method has a limit of detection of 5μg/kg and can be completed in 5‐7 min. The minicolumn technique has been expanded to include screening commodities other than peanuts for aflatoxin, as well as for other mycotoxins including ochratoxin, zearalenone and aflatoxin M 1.
Pons scaled‐down clean‐up column adapted for use in solvent‐saving modification of the CB method for aflatoxin
Authors: Lee L. S. , Catalano E. A. 
Published: July 2007

AbstractThe solvent‐saving procedure devised by Pons using a small Chromatographie tube (Bio‐Rad Laboratories glass Econo‐Column, 10 mm id X 300 mm long) has been adapted and extended for use in modifications of the Official AOAC procedure for quantitative determination of aflatoxins in corn, peanuts, soybeans, coconut and pistachios. Thirty mL of each of 3 solvents for column washes was used instead of the 150 mL specified by the Official CB Method. The analytical aliquot was also reduced 80%, but sample size and extracting solvent volume were not changed, so that there was no loss in sensitivity. Toxins ranging from 3 to over 1,000μg/g of sample were quantitated after clean‐up using both procedures with no statistically significant difference between results.
Preparation of14C‐labeled aflatoxins and incorporation of unlabeled aflatoxins in a blocked versicolorin‐A‐accumulating mutant ofaspergillus parasiticus
Authors: Floyd J. C. , Bennett J. W. 
Published: July 2007

AbstractWe have compared 2 methods for preparing radiolabeled aflatoxins from [14C] acetate for use in biosynthetic studies at the end of the aflatoxin pathway. The Salhab‐Edwards method (SE) used a 3‐day‐old mycelium and a defined medium containing MnCl2 with incubation at 28 C. The Lee‐Bennett method (LB) used a 2‐day‐old mycelium and a defined medium containing low levels of Mn with incubation at 30 C. Generally, the LB method produced lower quantities of aflatoxin but the product had higher specific activities (sp act). The SE method produced 0.157μmol of aflatoxin B1 and 0.028μmol of G1 compared to the LB method with 0.058μmol of aflatoxin B1 and 0.001μmol of G1. The sp act (inμCi/μmol) for aflatoxin produced by the LB method were: B1 = 1.379; B2 = 0.130; G1 = 5.0 and G2 ‐ 0.063. The sp act of aflatoxin produced by the SE method were: B1 = 0.267; B2 = 0.014; G1 = 0.178; and G2 =0.133. Unlabeled aflatoxins were presented to resting cell cultures of the versicolorin‐A‐accumulating mutant ofAspergillus parasiticus. No conversion of aflatoxin B, was noted. However, when aflatoxins B2 or G1 were presented low levels of aflatoxins B1 and G2 were recovered. Aflatoxins B2 and G1 were recovered when aflatoxin G2 was presented. Similar low levels of recovery were obtained in experiments using autoclaved mycelia. Thus we conclude that these minor quantities of aflatoxins recovered were not produced enzymatically.
Effect ofβ‐lonone onaspergillus flavus andaspergillus parasiticus growth, sporulation, morphology and aflatoxin production
Authors: Wilson D. M. , Gueldner R. C. , Mckinney J. K. , Lievsay R. H. , Evans B. D. , Hill R. A. 
Published: July 2007

AbstractThe ketoneβ‐ionone is reported to be one of the naturally occurring volatile metabolites of developing corn ears. In testing the effects of volatile compounds onAspergillus flavus andA. parasiticus, we found thatβ‐ionone applied to the surface of PDA plates had a striking inhibition of growth and sporulation of these fungi. The colonies were restricted, remained buff‐colored and had little or no sporulation. There were major effects on the morphology of the asexual reproductive structures. The conidiophore development was arrested and normal sporulation did not occur. Mycelial transfers from these atypical cultures to potato dextrose agar had normal growth and conidia. Incorporation ofβ‐ionone at levels of 10‐1000μL/L, in liquid media seeded with spore suspensions ofA. parasiticus (NRRL 2999) severely depressed aflatoxin accumulation in shake culture.
Effect of drought on occurrence ofaspergillus flavus in maturing peanuts
Authors: Sanders T. H. , Hill R. A. , Cole R. J. , Blankenship P. D. 
Published: July 2007

AbstractFlorunner peanuts were grown in experimental plots with soil moisture and soil temperature modified during the last third of the growing period to produce drought, drought with cooled soil, irrigated and irrigated with heated soil treatments. Twice each week, beginning 97 days after planting, random samples were harvested and maturities of individual pods were determined without destroying pod integrity. The nature and quantity of the microflora associated with the pods and kernels were subsequently assessed. Drought and lower soil temperature resulted in maturity distributions containing higher proportions of immature pods. On peanuts with no visible damage to the pod or kernel, colonization byAspergillus flavus was more frequent in immature than mature kernels. Drought stress increased the incidence ofA. flavus and irrigation decreased it, except when soil temperatures were modified.A. flavus infestation was greatly increased at all maturity levels by pod damage.
Bright greenish‐yellow fluorescence and aflatoxin in recently harvested yellow corn marketed in north carolina
Authors: Dickens J. W. , Whitaker T. B. 
Published: July 2007

AbstractCorn kernels that exhibited bright greenish‐yellow fluorescence (BGYF) under long‐wave ultraviolet light were hand‐picked from samples of yellow corn produced in eastern North Carolina. The BGYF kernels from 113 4‐kg samples contained an average of 8665 parts per billion (ppb) aflatoxin compared to an average of 46 ppb in the non‐BGYF kernels. A regression analysis between the ppb aflatoxin concentration and the wt % BGYF kernels in 2,304 4.5‐kg samples produced the regression equation: ppb in sample =197 (wt % BGYF). The correlation coefficient for the analysis was 0.90. Testing programs to reduce aflatoxin concentrations in purchased lots of corn based on either the BGYF method or the AOAC chemical assay method were compared. The average aflatoxin concentration in lots accepted by the AOAC method was 4 ppb, 10 ppb or 18 ppb when an acceptance level of < 20 ppb, < 50 ppb or < 100 ppb, respectively, was used. For the BGYF method, the average aflatoxin concentration in accepted lots was 10 ppb, 16 ppb or 22 ppb when an acceptance level of < 0.10% BGYF, < 0.25% BGYF or < 0.50% BGYF, respectively, was used. Approximately the same percentage of lots were accepted by both methods when either the low, medium or high acceptance level was used.
Effect of genotype (open‐pollinated vs hybrid) and environment on preharvest aflatoxin contamination of maize grown in southeastern united states
Authors: Stoloff L. , Lillehoj F. B. 
Published: July 2007

AbstractCurrently popular maize hybrids were compared with open‐pollinated varieties grown in die Southeast prior to 1940 for susceptibility to preharvest aflatoxin contamination. Parallel planting were made of 4 hybrids and 8 varieties at 8 locations, most located in the Southeast, in both 1979 and 1980. The test ears, dried immediately after picking, were examined for insect damage (1980 only) and the ground, shelled kernels analyzed for aflatoxins. Aflatoxin incidence and levels were positively related to location and crop year, but not to genotype, except for one variety that was significantly more susceptible to aflatoxin contamination than the others. There was no correlation of aflatoxin occurrence with either drought stress or maximal temperature during the period between flowering and harvest, but insect damage did correlate to some extent with the severity of contamination in 1980 both in relation to genotype and to location, except for the one location (Florence, SC) at which the most severe contamination was encountered. The severity of contamination at this location could not be explained by any of the known or hypothetical factors that have been developed.
Aflatoxin in freshly harvested 1979 georgia corn and formation after collection
Authors: Shotwell O. L. , Kwolek W. F. , Hesseltine C. W. 
Published: July 2007

AbstractIn the crop year 1979, freshly harvested dent corn was coUected at maturity in 57 sets of 2 equivalent samples/set. One set was dried the day of collection in Georgia and the other set was shipped to Peoria in corrugated cardboard boxes before drying, The set that was not dried in Georgia was shelled and dried as soon as possible after arrival in Peoria to prevent further aflatoxin formation. Both sets of samples were analyzed randomly at the Northern Regional Research Center, Peoria. In 22 Peoria‐dried samples, aflatoxin was detected in levels ranging from 2 to 449 ng/g total toxin but was not detected in the matching samples dried die same day of collection in Georgia. It took an average of 7 days to ship samples from Georgia. Of the 57 samples dried in Georgia, 63% were negative for aflatoxin; aflatoxin was below violative levels (>20 ng/g) in 82%; the average aflatoxin level in all samples was 36 ng/g. In the matching 57 samples dried in Peoria after shipment, aflatoxin was detected in all but 37%; aflatoxin was below violative levels in 70% of the samples; the average aflatoxin level in all samples that had been dried later was 78 ng/g. There was a significant increase in aflatoxin‐positive samples associated with shipment prior to drying. These results indicate that aflatoxin formed during shipment of the 1979 freshly harvested corn samples from Georgia.