sphing-4-enine + a fatty acid => an N-acylsphing-4-enine + H2O
sphing-4-enine + a fatty acid => an n-acylsphing-4-enine + h2o
sphing-4-enine + a fatty acid => an N-acylsphing-4-enine + H2O
sphing-4-enine + a fatty acid => an n-acylsphing-4-enine + h2o