d16:1

C16 Ceramide (d16:1,C16:0) is a bioactive sphingolipid that induces the formation and thermal stabilization of ordered phases and gel phases enriched in palmitoyl sphingomyelin domains within palmitoyl phosphatidylcholine (POPC) bilayers. It is found in human erythrocyte sphingomyelin.

C16 Sphingosine-1-phosphate (C16 S1P) is a derivative of sphingosine-1-phosphate that binds to S1P1/EDG-1, S1P3/EDG-3, and S1P2/EDG-5 receptors with affinities of 115%, 83%, and 103%, respectively, relative to S1P in CHO cells. C16 S1P was increased in postmortem primary open angle glaucoma trabecular meshwork samples.

Sphingosine (d16:1), an unconventional sphingolipid, is synthesized through enzymatic reactions starting with the condensation of myristoyl-CoA and serine by serine palmitoyltransferase long-chain base subunit 3 (SPTLC3), which shows a preference for myristoyl-CoA. This compound is found in minute quantities in its free form in human plasma and as a component of various plasma sphingolipids, such as sphingosine-1-phosphate, ceramides, sphingomyelins, and in brain cerebrosides, albeit at lower concentrations than the more common d18:1 sphingoid base. Sphingosine (d16:1) acts as an inhibitor of PKC in mixed micelle assays and diminishes superoxide production triggered by phorbol 12-myristate 13-acetate in isolated human neutrophils, as well as inhibiting the growth of CHO cells with IC50 values of 1 and 3.2 µM, respectively. Additionally, the concentration of sphingolipids containing sphingosine (d16:1) in the plasma is linked to the dietary consumption of saturated fatty acids and protein among ethnic Chinese populations.

Compound D16 (Anticancer agent 168) is an inhibitor of DNA2 that induces apoptosis and cell-cycle arrest predominantly in the S-phase. It demonstrates anticancer efficacy and can counteract chemotherapy resistance in cancers harboring mutant p53 [1].