Uwe Murawski

Minor constitutents of human milk IV: Analysis of the branched chain fatty acids

Abstract After catalytic hydrogenation of the unsaturated fatty acids, the branched chain fatty acids of human milk fat were enriched 100–500-fold by urea fractionation. The fatty acid (FA) mixture obtained was qualitatively and quantitatively analysed by a combination of gas chromatograph-mass spectrometer (LKB 9000) using packed columns, thin film and S.C.O.T. capillary columns. More than 50 single and multi branched acids could be identified. From the distribution of the individual branching points, it is concluded, that two major pathways exist for the biosynthesis of these acids: either by chain elongation of the branched CoA-esters (such as isobutyryl-CoA, α- and β-methylbutyryl-CoA) or by methylation of the double bond of monoenoic acids. The quantitative distribution of the branched acids strongly resembles that found in many micro-organisms. Hence it is assumed, that a large number of these acids is produced in - or absorbed from - the intestinal tract.

Unsaturated wax esters in the Harderian gland of the rat

Abstract The presence of ( n − 7) unsaturated alcohols and ( n − 7) monoenoic fatty acids in the wax esters of the Harderian gland of rats was established by gas-chromatography-mass spectrometry. The main components are the C 24:1( n − 7) alcohol and C 20:1( n − 7) fatty acid. It is suggested that desaturation in ( n − 7) position, nearly without exception, must be caused by a special system of desaturation and/or chain elongation.

Positional isomers of unsaturated fatty acids in rat liver lipids.

The fatty acids of liver lipids from rats raised on a fat free diet from the 30th to the 90th day after birth were analyzed with special regard to the detection of positional isomers of mono-, di-, tri-, and tetraenoic fatty acids. The methyl esters obtained after transesterification of total lipids were separated by argentation chromatography into five fractions: I saturated, II monoenoic, III dienoic, IV dienoic nonmethylene interrupted, V triand tetraenoic fatty acid esters. After hydroxylation of the double bonds with osmium tetroxide, the analysis of the poly-O-trimethylsilyl derivatives by gas liquid chromatography on S.C.O.T. columns combined with mass spectrometry revealed the presence of 19 monoenoic, 15 dienoic, and 9 trienoic as well as 3 tetraenoic fatty acid isomers including the normally occurring representatives of the (n−3), (n−6), (n−7), and (n−9) fatty acid families. The majority of the identified isomers can be coordinated to one of these families like 7–16∶1; 11–20∶1; 6,9–18∶2; 8,11–20∶2; 5,11–20∶2; 5,8,11–20∶3; 7,10,13–22∶3 to the (n−9) family, 11–18∶1; 13–20∶1; 5,11–18∶2; 7,13–20∶2; 6,11–18∶2; 6,9–16∶2; 8, 11–18∶2; 10,13–20∶2; 5,8,11–18∶3; 7,10,13–20∶3; 4,7,10,13–20∶4 to the (n−7) family and 11,14–20∶2; 5,11,14–20∶3; 6,9,12–18∶3; 8,11,14–20∶3; 5,8,11,14–20∶4; 7,10,13,16–22∶4 to the (n−6) family. All these naturally occuring isomers can be placed into a network of desaturation and chain elongation steps which allows certain conclusions about the substrate specificity of the Δ6-, Δ5-and Δ4-desaturase systems. The great number of isomers found in the (n−7) family indicates that the members of this family are actively metabolized in partial essential fatty acid deficiency.

Age-related changes of lipid fractions and total fatty acids in the serum of female and male rats aged from 37 to 1200 days

1. Total lipids and the lipid fractions cholesterol ester, triacylglycerols, free cholesterol, free fatty acids and phospholipids as well as the fatty acid patterns of total lipids were measured in the serum of female and male rats (Wistar SPF, strain Hannover) aged 37-1213 days. 2. All parameters were monitored every 49th day. Five female and five male animals were used in each experiment. 3. All lipid fractions showed a significant positive linear regression vs age in both sexes. There were multiple significant differences in lipid fractions between the sexes. 4. Among the fatty acids only docosahexaenoic acid shows a significant correlation with age in both sexes.

Massenspektren synthetischer methylen- und nicht-methylen-unterbrochener cis, cis-Oktadecadiensäure-methylester als Tetra-O-trimethylsilyläther / Mass Spectra of Synthetic Methylene- and Non-Methylene-Interrupted cis-cis-Methyl-Octadecadienoates as Their Tetra-O-Trimethylsilylether

The 20-eV-Mass spectra of eight methylene- and eight non-methylene-interrupted cis,cis-methyl-octadecadienoates as their tetra-O-trimethylsilyl derivatives are given. The fragmentation pattern dependent on the original position of double bonds and number of methylene-groups between the two double bonds is discussed.

Haematological values during normal reproduction of the maternal and the fetal rabbit.

1. Haematological values of non-pregnant/non-lactating, pregnant as well as lactating rabbits and 28-day-old fetuses were measured. 2. The haemoglobin content in does decreased during the observed periods from 122 +/- 8 g/l to 100 +/- 11 g/l. In 28-day-old fetuses it was 85 +/- 0 g/l. 3. The erythrocyte count in 28-day-old fetuses was 2.4 X 10(12)/l. In the does, the erythrocyte count was 5.2 X 10(12)/l in week 4 of gestation. The erythrocyte volume in fetuses was about 45% higher than that of the doe. 4. In fetuses the leucocyte count was approximately one ninth that of the mother in week 4 of gestation (0.41 +/- 0.08 X 10(9)/l vs 3.8 +/- 0.4 X 10(9)/l).

Iron and copper concentrations in the maternal and fetal serum, placenta and amniotic fluid during the reproductive stadium as well as in the milk of rabbits

Serum concentrations of iron and copper from rabbits (New Zealand White hybrids; N = 12) were determined during the reproductive stadium (gestation and four weeks of lactation). Samples of serum from fetuses, placental tissue and amniotic fluid were also examined. Iron: a decrease of iron in the maternal serum during the second half of gestation was observed, whilst a significant rise occurred in the first week of lactation. The content of iron in the fetal serum dropped from day 21 to day 28 of gestation. The iron concentration in the placental tissue decreased during this time. A rise of the iron level in the amniotic fluid was determined from day 21 to day 28 of gestation. The iron content in the milk was about 33 mumol/l (first and second day of lactation). Copper: in the first half of pregnancy the copper level diminished slightly compared with the content of non-pregnant, non-lactating rabbits, while a rise was observed in the fourth week of this period. The copper concentration decreased in the first week of lactation and then reached the peak level in the second week of this phase. The copper level in the fetal serum declined from day 21 to day 28 of gestation, while the copper content in the amniotic fluid increased significantly on day 28, in comparison with day 21 of gestation. In contrast, a decline of the copper concentration in the placental tissue was noticed from day 21 to day 28 of this period. The copper content in the milk was nearly 25 mumol/l (first and second day of lactation).

Keto-enediol-tautomerism of esters of 2,3-dihydroxy fatty acids

Abstract Gas-chromatographic-mass spectrometric evidence is presented for epimerization of esters of 2,3-dihydroxy fatty acids. Methyl erythro-2,3-dihydroxy octadecanoate produced by the action of osmium tetroxide on methyl cis-2-octadecenoate is partially epimerized to the threo-2,3-dihydroxy isomer under the influence of pyridine during the derivatization to the corresponding O-trimethylsilyl derivative. Both epimers can be separated by gas-chromatography and can be identified by their characteristic fragmentation patterns.

Age-related changes of lipid fractions and total fatty acids in liver lipids and heart lipids of female and male rats aged 37–1200 days (liver) and 331–1200 days (heart)

1. Total lipids and the lipid fractions cholesterol ester, triacylglycerol, free cholesterol, free fatty acids and phospholipids, as well as the fatty acid patterns of total lipids, were measured in liver homogenates of female and male rats (Wistar SPF, strain Hannover) aged 37-1213 days. 2. The same parameters were measured in the apex of the heart in female and male rats aged 331-1213 days. 3. All parameters were monitored every 49th day. Five female and five male animals were used in each experiment. 4. The lipid fractions in liver showed a positive linear regression vs age, whereas all lipids in rat heart showed a negative regression vs age in both sexes. 5. The significance of regression vs age of fatty acids was much less than that in the lipid fractions of liver and heart of these animals.

Die verzweigten Fettsäuren von Staphylococcus aureus, eine gaschromatographisch-massenspektrometrische Analyse / The Branched Chain Fatty Acids of Staphylococcus aureus, a Gas Chromatographic-Mass Spectrometric Analysis

The fatty acid methylesters prepared by transesterification of the total lipid extract of Staphylococcus aureus Wood 46 were analysed by gas chromatography on thin film capillaries coated with polyphenylether (OS 138), siliconerubber (SE 30) and S.C.O.T. columns coated with Diethyleneglycoladipatepolyester (DEGA) in combination with mass spectrometry. Among the branched chain fatty acids ranging from C11- C21 the iso- and anteiso-C15 acids are predominant. In the group of the C15 and C17 acids branching in position 9 and 10 was also found. No unsaturated branched chain fatty acids could be detected. Retention data and mass spectra of the branched chain fatty acids are presented.