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L E Francis

Publications and source records attributed to L E Francis.

17 recordsLinked to original sources
PubMed1978

The isolation and identification of 2,4-diketones present in human and animal tissues and in urine.

The chemical isolation of 2,3-diketone fraction from hydrolysates of various mammalian tissues has been accomplished by the use of a modified Girard T procedure. This fraction, which constitutes a new lipid class, has been resolved by gas chromatography into a number of homologous 2,4-diketones, ranging in chain length from C13 to C25. After separation by preparative gas chromatography, the following compounds have been unequivocally identified: 2,4-heptadecanedione, 2,4-nonadecanedione, 2,4-heneicosanedione, 2,4-docosanedione, and delta12-2,4-heneicosenedione. The 2,4-diketones appear to exist in tissues in the free state or in labile combination. They are present also in human urine.

Animals↗
PubMed1977

The preparation, gas liquid chromatography, and some physical and chemical properties of certain higher aliphatic 2,4-diketones--a new lipid class.

Fourteen saturated aliphatic 2,4-diketones, ranging in chain length from C7 to C25, and one unsaturated compound, delta12-2,4-heneicosenedione, were prepared by Claisen acylations of the appropriate methyl ketones, and their gas chromatographic behavior was studied. Mixtures of these diketones were resolved on columns containing UCW98 or Carbowax 20M stationary phases. Their methoxime and 2,4-dinitrophenylsemicarbazone derivatives were resolved on OV-17 and OV-1 stationary phases, respectively. Since higher homologous aliphatic 2,4-diketones have been found in mammalian tissues, they constitute a new lipid class.

Chromatography, Gas↗
PubMed1977

Some observations on the antihistamine activity in the guinea pig of aliphatic 2,4-diketones, a new class of physiological tissue components.

Eight saturated aliphatic 2,4-diketones, ranging in chain length from C7 to C21 were examined for their potency in counteracting the effects of histamine anaphylaxis in guinea pigs. A 0.2% suspension of the mixed C15, C17, C19 and C21 diketones was more effective than a 1% phenylephrine solution when these were administered as aerosols. Of the individual diketones, 2,4-nonadecanedione was the most potent in vivo. ED50 data for the antihistamine activity of the C7, C9, and C13 homologues in the in vitro guinea pig ileum bioassay indicated that, on a weight basis, the activity increased with increasing molecular weight. The antiallergic activity of tissue and of urine extracts has been attributed to the presence of 2,4-diketones.

Anaphylaxis↗