a 1,2-diacyl-3-(9Z,12Z-octadecadienoyl)-glycerol + an N-(omega-hydroxy-ultra-long chain fatty acyl)-sphingoid base = an N-[omega-(9Z,12Z-octadecadienoyloxy)-O-ultra-long chain fatty acyl]-sphingoid base + a 1,2-diacylglycerol — reaction