Simplified Gas Chromatography of Trimethylsilyl Esters of C1 through C5 Fatty Acids in Serum and Urine

1973 ◽  
Vol 19 (9) ◽  
pp. 1006-1009 ◽  
Author(s):  
O A Mamer ◽  
B F Gibbs

Abstract All the metabolically important C1 through C5 fatty acids and lactic, pyruvic and β-hydroxybutyric acids can be gas chromatographed surprisingly well on the common 2-meter 3% methylphenylsilicone (e.g., "OV-17") column when a late-eluting silylating reagent such as trimethylsilylimidazole is used. In these circumstances, the trimethylsilyl esters elute in an interval that is free of the reagent and solvent interferences usually found when the more volatile preparations are used for silylations. Use of the method is demonstrated by its application to a serum from a case of isovaleric acidemia and a urine from a case of methylmalonic aciduria.

1990 ◽  
Vol 45 (6) ◽  
pp. 691-697 ◽  
Author(s):  
A. B. Attygalle ◽  
J. P. J. Billen ◽  
B. D. Jackson ◽  
E. D. Morgan

Abstract The morphology and ultrastructure of the Dufour gland of a pseudomyrmecine ant is described. The gland has an unusually large volume but possesses a very thin epithelial lining. Its morphology does not constitute a specific subfamily character as in some ant subfamilies. Analysis by gas chromatography-mass spectrometry of the glands of three species showed them all to be rich in saturated linear hydrocarbons (C17:0 and C15:0 dominant) and isopropyl esters of the common fatty acids. Each species produces its own characteristic mixture of these substances. The most abundant ester in Pseudomyrmex ferruginea is isopropyl oleate and in P. sp. A it is isopropyl palmitate, in P.flavicornis there is only a trace of isopropyl palmitate. An alate female of P. ferruginea contained a very similar mixture to that of the workers.


ChemPlusChem ◽  
2015 ◽  
Vol 80 (5) ◽  
pp. 839-850 ◽  
Author(s):  
Petr Žáček ◽  
Jiří Kindl ◽  
Kateřina Frišonsová ◽  
Markéta Průchová ◽  
Alena Votavová ◽  
...  

2021 ◽  
pp. 1-5
Author(s):  
Tayanna Bernardo Oliveira Nunes Messias ◽  
Susana Paula Alves ◽  
Rui José Branquinho Bessa ◽  
Marta Suely Madruga ◽  
Maria Teresa Bertoldo Pacheco ◽  
...  

Abstract In this research communication we describe the composition of fatty acids (FA) present in the milk of the Nordestina donkey breed, and how they differ during lactation. Milk samples were taken from 24 multiparous lactating Nordestina donkeys that grazed the Caatinga, comprising 5 animals at each of around 30, 60 and 90 d in milk (DIM) and a further 9 animals ranging from 120 to 180 DIM. The milk fat content was analysed by mid infrared spectroscopy and the FA profile by gas chromatography. The milk fat percentage ranged from 0.45 to 0.61%. The main FA found in milk were 16:0 and 18:1c9. These did not differ among DIM classes and comprised 23% and 25% of total FA. Notably, the α-Linolenic acid (18:3 n-3) was the third most abundant FA and differed (P < 0.05) with DIM, being lowest in the 30 and 60 DIM samples (around 10.7% of total FA) and highest in the 60 and 90 DIM classes (around 14.6% of total FA). The low-fat content and the FA profile of the donkey milk gives it potential as a functional ingredient, which could help to preserve the commercial viability of the Nordestina donkey breed.


2011 ◽  
Vol 6 (11) ◽  
pp. 1934578X1100601 ◽  
Author(s):  
Ali Shafaghat

The hexane extracts of flower, leaf, stem, and seed of Hypericum scabrum, which were collected from northwestern Iran, were obtained by extraction in a Soxhlet apparatus. The fatty acids were converted to methyl esters and determined by gas chromatography/flame ionization detector (GC/FID) and gas chromatography/mass spectrometry (GC/MS) systems. The hexane extract from the flower, leaf, stem, and seed contained 39.1%, 43.2%, 29.0%, and 37.6% of omega-3 fatty acids, respectively. The other main components of the flower extract were tetracosane (12.2%) and palmitic acid (9.3%), and that of the leaf extract was palmitic acid (7.4%). The stem and seed extracts contained bis(2-ethylhexyl)phthalate (18.7% and 35.7%), nonacosane (11.7% and 3.9%) and linoleic acid (6.5% and 6.9%) as major components. The hexane extracts of different parts from H. scabrum represent an important source of omega-3 fatty acids in several Hypericum species. The antioxidant activity of all hexane extracts was evaluated by the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging method. The results indicate that hexane extracts from different parts of H. scabrum possess considerable antioxidant activity. The highest radical scavenging activity was detected in seed, which had an IC50 = 165 μg/mL. The antimicrobial activity of the extracts of those samples were determined against seven Gram-positive and Gram-negative bacteria ( Bacillus subtilis, Enterococcus faecalis, Staphylococcus aureus, S. epidermidis, Escherichia coli, Pseudomonas aeruginosa, and Klebsiella pneumoniae), as well as three fungi ( Candida albicans, Saccharomyces cerevisiae, and Aspergillus niger). The bioassay showed that the oil exhibited moderate antimicrobial activity. This study reveals that the all parts of this plant are attractive sources of fatty acid components, especially the essential ones, as well as of effective natural antioxidants.


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