Glycerol Tripalmitate Research Articles

The role of maternal triglycerides in the supply of lipids to the ovine fetus

Maternal and fetal blood samples were obtained for up to 20 min after the injection of an emulsion of 14C-labelled glycerol tripalmitate into the circulation of pregnant ewes. No evidence was obtained for the direct transfer of intact triglycerides across the placenta. Results obtained suggest that there was a very rapid uptake of the triglyceride from the maternal circulation followed by hydrolysis and release of free fatty acids back into the maternal circulation.

Intermolecular specificity of pancreatic lipase in the lipolysis of triacylglycerols containing phytanic acid.

Treatment of mixtures of glycerol tripalmitate and rac-glycerol 1,2-dipalmitate 3-phytanate with pancreatic lipase demonstrated that phytanic acid retarded the release of palmitic acid esterified in the same triacylglycerol.

Determination of serum triglycerides by mass fragmentography

A mass fragmentographic reference method for determination of serum triglycerides is described. A fixed amount of a mixture of [1,1,2,2,3,3- 2H 5]glycerol tripalmitate and [1,1,2,2,3,3- 2H 5]glycerol trioleate (500 nmol) is added to a fixed amount of serum (250 μ1) and extracted with Chloroform/methanol (2:1, v/v). The triglycerides are isolated by means of thin-layer chromatography. The glycerol obtained after acid hydrolysis is converted into the tri-trimethylsilyl derivative and the amount of unlabeled glycerol is determined from the ratio between the recordings at m/ e 218 and m/ e 222, obtained after analysis with a gas chromatograph-mass spectrometer equipped with an MID (multiple ion detector). The two ions correspond to the peak at M−90 and M−91 in the mass spectrum of the tri-trimethylsilyl derivative of unlabeled and (1,1,2,3,3- 2H 5)-labeled glycerol. The relative standard deviation of the method in the range 0.4–5.8 mm 01/1 was 2.4%. A fully enzymatic routine method for determination of triglycerides was compared with the mass fragmentographic reference method. There was a good correlation between the two methods ( r = 0.995) and the regression coefficient was 1.19.

Carnitine Ester Hydrolase of Rat Liver

Abstract Rat liver, kidney, pancreas, and small intestine have enzymes which hydrolyze fatty acid esters of carnitine. The liver enzyme, located in the microsomal fraction, was solubilized by sonic disruption and purified 18-fold by diethylaminoethyl cellulose chromatography and Sephadex gel filtration. The purified enzyme sedimented in the ultracentrifuge as a single protein with an s20,w of 4.5 S. The enzyme had maximum activity at pH 7.5 and hydrolyzed higher fatty acid (C6 to C18) esters of l-carnitine. d-Carnitine esters were not hydrolyzed. Esters of dl-carnitine were hydrolyzed only about one-half as efficiently as those of the l isomer. The enzyme did not hydrolyze palmitoyl coenzyme A, p-nitrophenyl palmitate, glycerol tripalmitate, and cholesterol palmitate, but it catalyzed the hydrolysis of glycerol monopalmitate to a slight extent. Among the l-carnitine esters, maximum rate of hydrolysis was obtained with the decanoate ester. The Km for decanoate ester was 3.2 x 10-3 m and for the palmitate ester 5 x 10-3 m. The enzyme was not affected by l-carnitine, dl-carnitine, d-carnitine, ethylenediaminetetraacetic acid, and Mg++ but it was inhibited by decanoyl-d-carnitine, Ca++, Cu++, NaF, sulfhydryl reagents, and sodium cholate, and it was activated by bovine serum albumin. The properties of carnitine ester hydrolase which distinguish it from microsomal esterase and microsomal lipase are discussed.

Variations in crystal structure within certain isologous series of long‐chain compounds. A review of some basic features

SummaryCrystal structures of many long‐chain compounds appear classifiable intoalpha, beta prime, orbeta cross‐sectional types, in which, respectively, the rows of parallel chains have axes randomly oriented, identically oriented within a row but with orientation alternating among the rows, or identically oriented throughout. Members of two isologous series are compared with particular regard to the cross‐sectional type. The series are (I) methyl palmitate (P), ethylene glyco dipalmitate (PP), glycerol tripalmitate (PPP), and m‐erythritol tetrapalmitate (PPPP); and (II) the corresponding stearates. The following behavior is observed—P:beta prime; PP:beta prime; PPP:alpha, beta prime, beta; PPPP:beta prime, beta; and similarly for the stearate series but with an additionalalpha form for SSSS. Other compounds are considered with respect to tendency to form various cross‐sectional types.