[{"from": "human", "value": "Generate a molecule based on the given description. The molecule is an N-acyl-15-methylhexadecasphing-4-enine in which the acyl group has 21 carbons and 0 double bonds. It has a role as a Caenorhabditis elegans metabolite. It is a N-acyl-15-methylhexadecasphing-4-enine and a Cer(d38:1). It is functionally related to a 15-methylhexadecasphing-4-enine and a henicosanoic acid."}, {"from": "gpt", "value": "[C][C][C][C][C][C][C][C][C][C][C][C][C][C][C][C][C][C][C][C][C][=Branch1][C][=O][N][C@@H1][Branch1][Ring1][C][O][C@@H1][Branch1][P][/C][=C][/C][C][C][C][C][C][C][C][C][C][Branch1][C][C][C][O]"}]