Vernix caseosa protects the skin of a human fetus during the last trimester of pregnancy and of a newborn after the delivery. Besides its cellular and proteinaceous components, an important constituent and functional agent is a complex lipid fraction, implicated in a multitude of salubrious effects of vernix caseosa. Little is known about how the chemical composition of vernix caseosa lipids is affected by various biological characteristics of the baby, such as the gestational age, birth weight, and, last but not least, the gender of the newborn. This study reports on the chemical variability of lipids contained in the vernix caseosa of twenty newborn girls and boys and shows that the quantitative patterns of the lipids are sex-specific. The specificity of lipids was investigated at the level of fatty acids in the total lipid extracts and intact lipids of several neutral lipid classes. Hydrocarbons, wax esters, cholesteryl esters, diol diesters and triacylglycerols were isolated using optimized semipreparative thin-layer chromatography, and the molecular species within each class were characterized using matrix-assisted laser desorption/ionization mass spectrometry. Statistical evaluation revealed significant quantitative sex-related differences in the lipid composition of vernix caseosa among the newborns, pronounced in the two lipid classes associated with the activity of sebaceous glands. Higher proportions of wax esters and triacylglycerols with longer hydrocarbon chains were observed in newborn girls.

• MeSH
• chromatografie na tenké vrstvě MeSH
• kůže chemie   MeSH
• lidé MeSH
• lipidy analýza   MeSH
• novorozenec MeSH
• plynová chromatografie s hmotnostně spektrometrickou detekcí MeSH
• sexuální faktory MeSH
• spektrometrie hmotnostní - ionizace laserem za účasti matrice MeSH
• těhotenství MeSH
• vernix caseosa chemie   MeSH
• Check Tag
• lidé MeSH
• mužské pohlaví MeSH
• novorozenec MeSH
• těhotenství MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• srovnávací studie MeSH
• Názvy látek
• lipidy MeSH

The interpretation of the electron ionization mass spectra of straight-chain and methyl-branched saturated and unsaturated wax esters (WEs) is discussed in this study based on the spectra of 154 standards. The most important fragments indicative of the structure of the acid and alcohol chains are identified and summarized for WEs with various number of double bonds in the chains. Briefly, most WEs provide acylium ions allowing structural characterization of the acid part, whereas the alcohol part gives corresponding alkyl radical cations. The elemental composition of selected important fragments is established from a high-resolution accurate mass analysis. The ion abundances are discussed with respect to the length and unsaturation of the aliphatic chains. The interpretation of the spectra of branched or unsaturated WEs requires the recognition of small but important peaks that are difficult to discern among the other fragments. We demonstrate that such fragments are easily detected in differential mass spectra. This approach requires spectra of WE standards (e.g., straight-chain analogs in the case of branched WEs) recorded under the same experimental conditions. The WEs mass spectral database provided in the supplemental data can be used as a reference for the analysis of the GC/EI-MS data.

• MeSH
• estery chemie   MeSH
• hmotnostní spektrometrie s elektrosprejovou ionizací metody   MeSH
• nenasycené mastné kyseliny chemie   MeSH
• plynová chromatografie s hmotnostně spektrometrickou detekcí metody   MeSH
• referenční standardy MeSH
• vosky chemie   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• estery MeSH
• nenasycené mastné kyseliny MeSH
• vosky MeSH

The spatial distribution of neutral lipids and hydrocarbons has been imaged using MALDI-TOF mass spectrometry on intact plant and insect surfaces, namely wings and legs of the gray flesh fly (Neobellieria bullata), wings of common fruit fly (Drosophila melanogaster), leaves of thale cress (Arabidopsis thaliana), and leaves of date palm tree (Phoenix sp.). The distribution of wax esters (WEs) and saturated and unsaturated hydrocarbons (HCs) was visualized. The samples were attached on a target and multiply sprayed with lithium or sodium 2,5-dihydroxybenzoate. The deposits were homogenous, consisting of small islands (50-150 microm) of matrix crystals separated by small areas (10 microm) of uncovered cuticle. Samples of N. bullata wings were found to contain HCs and WEs distributed close to their basal parts. The distribution of sodium and potassium ions was visualized on samples prepared by sublimation of 2,5-dihydroxybenzoic acid. Pheromonal dienes were detected on D. melanogaster female wings. A homogenous distribution of saturated WEs was observed on A. thaliana and Phoenix sp. leaf samples. The optimum number of laser shots per pixel was found to be higher than for polar compounds imaging.

• MeSH
• Arabidopsis anatomie a histologie   chemie   MeSH
• Arecaceae anatomie a histologie   MeSH
• Diptera anatomie a histologie   chemie   MeSH
• draslík chemie   MeSH
• Drosophila melanogaster anatomie a histologie   MeSH
• fotografování MeSH
• gentisáty chemie   MeSH
• hmyzí proteiny chemie   MeSH
• křídla zvířecí anatomie a histologie   chemie   MeSH
• lipidy analýza   chemie   MeSH
• listy rostlin chemie   MeSH
• lithium chemie   MeSH
• počítačové zpracování obrazu metody   MeSH
• rostlinné proteiny chemie   MeSH
• sodík chemie   MeSH
• spektrometrie hmotnostní - ionizace laserem za účasti matrice metody   MeSH
• uhlovodíky chemie   MeSH
• zvířata MeSH
• Check Tag
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• 2,5-dihydroxybenzoic acid MeSH Prohlížeč
• draslík MeSH
• gentisáty MeSH
• hmyzí proteiny MeSH
• lipidy MeSH
• lithium MeSH
• rostlinné proteiny MeSH
• sodík MeSH
• uhlovodíky MeSH