(4R)-hydroxysphinganine + (9Z)-octadecenoate => N-(9Z-octadecenoyl)-(4R)-hydroxysphinganine + H2O
(4r)-hydroxysphinganine + (9z)-octadecenoate => n-(9z-octadecenoyl)-(4r)-hydroxysphinganine + h2o
(4R)-hydroxysphinganine + (9Z)-octadecenoate => N-(9Z-octadecenoyl)-(4R)-hydroxysphinganine + H2O
(4r)-hydroxysphinganine + (9z)-octadecenoate => n-(9z-octadecenoyl)-(4r)-hydroxysphinganine + h2o