Vernix caseosa, the waxy substance that coats the skin of newborn babies, has an extremely complex lipid composition. We have explored these lipids and identified nonhydroxylated 1-O-acylceramides (1-O-ENSs) as a new class of lipids in vernix caseosa. These ceramides mostly contain saturated C11-C38 ester-linked (1-O) acyls, saturated C12-C39 amide-linked acyls, and C16-C24 sphingoid bases. Because their fatty acyl chains are frequently branched, numerous molecular species were separable and detectable by HPLC/MS: we found more than 2,300 molecular species, 972 of which were structurally characterized. The most abundant 1-O-ENSs contained straight-chain and branched fatty acyls with 20, 22, 24, or 26 carbons in the 1-O position, 24 or 26 carbons in the N position, and sphingosine. The 1-O-ENSs were isolated using multistep TLC and HPLC and they accounted for 1% of the total lipid extract. The molecular species of 1-O-ENSs were separated on a C18 HPLC column using an acetonitrile/propan-2-ol gradient and detected by APCI-MS, and the structures were elucidated by high-resolution and tandem MS. Medium-polarity 1-O-ENSs likely contribute to the cohesiveness and to the waterproofing and moisturizing properties of vernix caseosa.

• Klíčová slova
• ceramides, lipidomics, lipids, mass spectrometry, skin,
• MeSH
• ceramidy metabolismus   MeSH
• hmotnostní spektrometrie s elektrosprejovou ionizací MeSH
• hmotnostní spektrometrie MeSH
• kůže metabolismus   MeSH
• lidé MeSH
• lipidy krev   MeSH
• magnetická rezonanční spektroskopie MeSH
• novorozenec MeSH
• plynová chromatografie s hmotnostně spektrometrickou detekcí MeSH
• vernix caseosa metabolismus   MeSH
• vysokoúčinná kapalinová chromatografie MeSH
• Check Tag
• lidé MeSH
• novorozenec MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• ceramidy MeSH
• lipidy MeSH