has role Mycoplasma genitalium metabolite Cer(d34:1) N-palmitoyl-sphingoid base hexadecanoic acid N-acylsphingosine N-hexadecanoylsphingosine A N-acylsphingosine in which the ceramide N-acyl group is specified as hexadecanoyl (palmitoyl). human blood serum metabolite