Fatty acid distribution of cord and maternal blood in human pregnancy: special focus on individual trans fatty acids and conjugated linoleic acids

<p>Abstract</p> <p>Background</p> <p>Maternal nutrition in pregnancy has a crucial impact on the development of the fetus. Dietary <it>trans </it>fatty acids (<it>t</it>FA) are known to have adverse health effects, especially during pregnancy. However, the distribution of <it>t</it>FA produced via partial hydrogenation of vegetable oils (mainly elaidic acid; <it>t</it>9) differs compared to ruminant-derived <it>t</it>FA (mainly vaccenic acid; <it>t</it>11). Recent findings indicate that they may have different impact on human health.</p> <p>Therefore, in this study, plasma and erythrocytes of mother-child pairs (n = 55) were sampled to investigate the distribution of <it>t</it>FA, including individual <it>trans </it>C18:1 fatty acids and conjugated linoleic acids (CLA) in fetal related to maternal lipids; with additional consideration of maternal dairy fat intake.</p> <p>Results</p> <p>Portion of <it>t</it>9 and <it>t</it>11, but also of <it>c</it>9,<it>t</it>11 CLA was higher in maternal than in fetal blood lipids. The portion of <it>t</it>9 in maternal and fetal lipids differed only slightly. In contrast, the portion of fetal <it>t</it>11 was only half of that in maternal blood. This led to a fetal <it>t</it>9/<it>t</it>11-index in plasma and erythrocytes being twice as high compared to the maternal values. A high dairy fat intake resulted in elevated portions of <it>t</it>11 and its Δ9-desaturation product <it>c</it>9,<it>t</it>11 CLA in maternal blood. In contrast, in the respective fetal blood lipids only <it>c</it>9,<it>t</it>11 CLA, but not <it>t</it>11 was increased. Nevertheless, a positive association between maternal and fetal plasma exists for both <it>t</it>11 and <it>c</it>9,<it>t</it>11 CLA. Furthermore, in contrast to <it>t</it>9, <it>t</it>11 was not negatively associated with n-3 LC-PUFA in fetal blood lipids.</p> <p>Conclusions</p> <p>Fetal blood fatty acid composition essentially depends on and is altered by the maternal fatty acid supply. However, in addition to dietary factors, other aspects also contribute to the individual fatty acid distribution (oxidation, conversion, incorporation). The lower portion of fetal <it>t</it>11 compared to maternal <it>t</it>11, possibly results from Δ9-desaturation to <it>c</it>9,<it>t</it>11 CLA and/or oxidation. Based on the fatty acid distribution, it can be concluded that <it>t</it>11 differs from <it>t</it>9 regarding its metabolism and their impact on fetal LC-PUFA.</p

Structure elucidation and activity of kolossin A, the D-/L-Pentadecapeptide product of a giant nonribosomal peptide synthetase

The largest continuous bacterial nonribosomal peptide synthetase discovered so far is described. It consists of 15 consecutive modules arising from an uninterrupted, fully functional gene in the entomopathogenic bacterium Photorhabdus luminescens. The identification of its cryptic biosynthesis product was achieved by using a combination of genome analysis, promoter exchange, isotopic labeling experiments, and total synthesis of a focused collection of peptide candidates. Although it belongs to the growing class of D-/ L-peptide natural products, the encoded metabolite kolossin A was found to be largely devoid of antibiotic activity and is likely involved in interspecies communication. A stereoisomer of this peculiar natural product displayed high activity against Trypanosoma brucei rhodesiense, a recalcitrant parasite that causes the deadly disease African sleeping sickness