The Lipids of Schistosomes During their Various Stages of Growth

Presence of appreciable amount of squalene in the intermediate stages of both species of schistosomes was detected. Squalene was found to be absent in adult S. mansoni worm. The major components of the developmental stages of schistosomes were assessed as well. Chromatographic separation of lipid classes of the livers of biomphalaria snails, both infected with S. mansoni and uninfected was also carried out.     

The antioxidant activity of amino acids in two vegetable oils

Of 27 amino acids studied, most had some antioxidant activity when added in aqueous solution to either safflower oil or a mixture of sunflower and cottonseed oil (active oxygen and storage methods). Cysteine-HCl, glutamic acid-HCl (in the mixture), and glutamic acid-HCl (in safflower oil) behaved as prooxidants. When added as a solid, most amino acids were ineffective. The protection factors of these amino acids were less than 1.3 in safflower oil with methionine, proline, lysine and cysteine providing the highest activ-ity. In the oil mixture (which had a higher metal content) lysine, arginine, glutamic acid, methionine, and hydroxyproline were anti-oxidant with protection factors of up to 1.85. Chelation of metals by amino acids was presumably responsible for the antioxidant activity. The increase in cysteine concentration up to 1% has more than doubled the protection factor in Bint oil (compared with the 0.01% level), whereas with some other amino acids the increase was either small or slight.     

A polyamide-silica composite prepared by the sol-gel process

Summary A new kind of organic-inorganic hybrid composite was prepared by means of the sol-gel process. The polymer employed was a mixed-isomer aromatic polyamide having good solubility and thermal stability. The silica constituting the inorganic phase was produced by the hydrolysis and condensation of tetramethoxysilane. The bonding between the phases involved aminophenyl-trimethoxysilane, in which the amino group can react with the phthaloyl chloride end-capped polymer, and the methoxysilane groups undergo hydrolysis. The composition of these composites was varied by changing the linear polymer chain length and relative amount of tetramethoxysilane. The gelation time was found to range from a few minutes to several days. Thermogravimetric analyses showed that decomposition starts at approximately 450 °C. Thin films cast from materials having a relatively high silica content were opaque and rigid, but those with low silica content were flexible and transparent.     

Cyclopropenoid fatty acids ingnetum scandens and itsterculia pallens seed oils

Seed oils ofGnetum scandens (Gnetaceae) andSterculia pattens (Sterculiaceae) were found to contain sterculic (28.57,6.97) and malvalic (11.27,3.87) acids, respectively. Gas Chromatographic analysis of silver nitrate/meth-anol-treated methyl esters was used to establish the co-occurrence of these two acids.Sterculia foetida methyl esters were used as a reference standard.     

Acacia albida Seed Oil: Characterization of Coronaric Acid

Coronaric acid makes up 7.8% of Acacia albida (leguminosae) oil triglycerides. Direct acetolysis of the oil followed by saponification gave cis-9,10-dihydroxyoctadec-cis-12-enoic acid which was characterized by various spectroscopic studies and chemical transformations. Quantitation of the coronaric acid was done by gas-liquid chromatography. Chrysanthemum coronarium seed oil was used as the reference standard throughout the study.     

Structure and Biological Significance of Triacylglycerols Containing Cyclopropene Acyl Moieties

Cyclopropene fatty acids are constituents of seed lipids of various plants, including sources of edible fats, such as cottonseed and kapok. Physiological and toxicological properties of lipids containing cyclopropene acyl moieties are reviewed and the difficulties encountered in the elucidation of the structures of triacylglycerols containing cyclopropene acyl moieties are discussed. A novel method for the analysis of such triacylglycerols is presented.     

Kigelia pinnata Seed Oil – A Moderate Source of Vernolic Acid

Vernolic acid represents 22.3% of the constituent fatty acids of the speed oil of an additional hitherto unexamined species of Bignoniaceae Kigelia pinnata. Its identification is based on comparative informations from thin-layer chromatography, infrared analysis, gas liquid chromatography and nuclear magnetic resonance spectroscopy with that of reference sample of Vernonia anthelmintica seed oil. The other fatty acids in this oil are: 14:0 (0.4), 16:0 (25.4), 18:0(0.9), 18:1 (8.9) and 18:2 (42.0%). K. pinnata is the first species of Bignoniaceae to be reported to contain vernolic acid in moderate amount.     

Ricinoleic acid inPhyllanthus niruri seed oil

Seed oil ofPhyllanthus niruri (Euphorbiaceae) contains 1.2% ricinoleic (12-hydroxy-cis-9-octadecenoic) acid, previously unknown in the genusPhyllanthus. Identification is based on thin layer and gas liquid chromatography, infrared, nuclear magnetic resonance, and mass spectrometry analysis as well as chemical methods. Other major components of the oil are linoleic acid (21%) and linolenic acid (51.4%). Presented at the ISF/AOCS World Congress, April 1980, New York City.     

Palladium- catalyzed hydrogenation of soybean oil

The hydrogenation of soybean oil has been studied using charcoal-supported palladium catalysts at hydrogen pressures between ambient and 70 psig and at temperatures between 80 C and 160 C in three types of stirred reactor. The catalysts employed were 1-10% w/w Pd supported on charcoal and represented differing metal placement on the support. The structure of the catalysts was confirmed by metal surface area measurements, transmission electron microscopy (TEM) and electron spectroscopy for chemical analysis (ESCA). Comparative studies also were carried out under similar conditions using samples of commercial nickel catalysts. Palladium catalysts with the metal placed on the exterior of the charcoal support were the most active and selective at ambient pressure, and although palladium catalysts with metal placed within the charcoal pore system became the most active at higher hydrogen pressures, only the former type of catalyst retained high selec-tivity over the whole temperature and pressure range. Palladium catalysts gave rise to moretrans- acids than nickel, particularly under conditions normally em-ployed with the latter, but if diffusion limitation was avoided, especially at lower temperatures, palladium gave lower quantities oftrans- acid than nickel. In addition, the selectivity of a well designed palladium catalyst was superior to that of nickel and its activity was 15-20 times greater. It is concluded that if palladium is deposited on the exterior of the charcoal so that it is accessible to the triglyceride molecules, then its selectivity and activity is superior to that of nickel, even at low temperatures, at which nickel is inactive. This underlines the importance of choosing the correct preparative route to give optimum metal placement, and it is suggested that when previous studies have indicated that palladium is unselective for fat hardening, it is likely that the metal was not dispersed on the exterior surface of the support. Furthermore, whereas nickel is best used under diffusion-controlled conditions because its selectivity is better in the latter situation palladium should be used under diffusion-free conditions, which implies that very careful attention should be paid to the reactor design.     

Reaction of methyltrans-2,3-epoxyhexadecanoate with urea: Synthesis of long chain fatty 2-oxazolidones

Methyltrans-2,3-epoxyhexadecanoate on refluxing with urea in dimethylformamide (DMF) afforded isomeric 4(5)-tridecyl-5(4)-carbomethoxy-cis-2-oxazolidone (II), 5-tridecylmethylene hydantoin (II) and 2-hydroxy-3-carbamidohexadecanoic acid (III). Presented at the 4th Convention of the Indian Council of Chemists at Uttar Pradesh, India, December 1984.