Identification of an unusual naturally occurring apolar fatty acid amide in mammalian brain and a method for its quantitative determination.
Fatty acid amides (FAAs), such as the N-acylamides, N-acylethanolamides, N-acyldopamines and N-acylamino acids, are now emerging as an important new class of lipid-signalling molecules. This paper provides evidence, based on high-performance liquid chromatography/electrospray ionisation mass spectrometry (HPLC/ESI-MS/MS), gas chromatography/mass spectrometry (GC/MS) and 1H-NMR, of the occurrence in mouse and bovine brain extracts of a compound characterised by a mass spectrum attributable to a FAA not previously described, namely, the isopropyl-amide of stearic acid (SIPA). A highly sensitive GC/MS method was developed for quantification of naturally occurring SIPA and, also, for purposes of comparison, that of palmitoylethanolamide (PEA), a structurally related compound commonly determined in animal tissues. The results obtained show that SIPA levels in mouse brain are 8-10-fold higher than those of PEA. Moreover, SIPA was found in human neuroblastoma cell (SHSY-5Y) extracts, at significantly higher levels following exposure of the cells to the mitochondrial inhibitor rotenone. All this evidence not only shows surprisingly that SIPA may be found naturally in mammalian biological extracts despite the unusual functional group (i.e. isopropylamide) implicated, but also raises many important questions concerning its biological origin.
Dalle Carbonare
Maurizio
M
Research & Innovation (R&I) Company, via Svizzera 16, 35127 Padova, Italy. mdallecarbonare@researchinnovation.com
Tonidandel
Loris
L
Berto
Fiorenzo
F
Luise
Diego
D
Mardegan
Andrea
A
Giordano
Giuseppe
G
Da Dalt
Liviana
L
Guiotto
Adriano
A
Battistin
Leontino
L
Leon
Alberta
A
Traldi
Pietro
P
D000818:Animals; D001923:Brain Chemistry; D002417:Cattle; D045744:Cell Line, Tumor; D002851:Chromatography, High Pressure Liquid; D005227:Fatty Acids / Q000032:analysis* / Q000737:chemistry* / Q000302:isolation & purification; D005260:Female; D008401:Gas Chromatography-Mass Spectrometry; D006801:Humans; D051379:Mice; D008807:Mice, Inbred BALB C; D012680:Sensitivity and Specificity; D021241:Spectrometry, Mass, Electrospray Ionization; D013329:Structure-Activity Relationship
D005227:Fatty Acids