N-(2-hydroxytetracosanoyl)-(4R)-hydroxysphinganine + NADPH + O2 + H(+) => N-(2,3-dihydroxytetracosanoyl)-(4R)-hydroxysphinganine + NADP(+) + H2O
n-(2-hydroxytetracosanoyl)-(4r)-hydroxysphinganine + nadph + o2 + h(+) => n-(2,3-dihydroxytetracosanoyl)-(4r)-hydroxysphinganine + nadp(+) + h2o