KCS

Ceramides (CERs) are mostly distributed in stratum corneum (SC) of skin epidermis layer and protect from noxious external environmental such as various allergen, pathogen and water evaporation. CERs are mainly composed of total 16 subclasses (Cer [NdS, NS, NP, NH], Cer [AdS, AS, AP, AH], Cer [EOdS, EOS, EOP, EOH], Cer [OdS, OS, OP, OH]) according to variable structure and chain length of fatty acid chain, sphingosine chain and polar head group. Above all, the SC of skin almost consists of N-type and A-type CERs. The analyses of CERs species have mainly used to normal-phase (NP) LC-APCI-MS with TLC method and reversed-phase (RP) LC/Q-TOF MS. To compare change of CERs species level between health skin and atopic dermatitis skin, we performed profiling and quantification of CERs in tape-stripped SC by RP-UPLC/Q-TOF MS, 15T FT-ICR MS and orbitrap MS. The use of XBridge BEH C18 Shield column (RP column), aminopropyl (NH₂) SPE cartridge and 7.5 mM ammonium acetate increased separation efficiency and ionization efficiency of CERs species. The acquired data was analyzed by principal component analysis (PCA) and orthogonal partial least square discrimination analysis (OPLS-DA) to investigate major alteration of CERs class by atopic dermatitis.