Biochemistry of Shellfish Lipids X. Isolation of a Sphingolipid Containing 2-Monomethylamino- ethylphosphonic Acid from Shellfish

1. A new sphingophosphonolipid was prepared from a mollusc, Monodonta labio, and characterized as ceramide 2-monomethylaminoethylphosphonate (CMMAEP). 2. The lipid was completely hydrolyzed by Cl. perfringens phospholipase C [EC 3.1.4.3] in the presence of diethyl ether. Among the products in the hydrolyzate, 2-monomethylaminoethylphosphonic acid and ceramide were isolated and identified. 3. A method is presented for isolating CMMAEP from alkali-stable lipid mixtures of the mollusc. The occurrence of a G-P bond in nature was first revealed by HORIGUCHI and KANDA-TSU (1959) ( 1) when they isolated 2-amino-ethylphosphonic acid (AEP) from acid hy-drolyzates of a proteolipid-like substance pre-pared from the protozoa of sheep rumen. Since then several workers have obtained evidence that the same compound is present in aquatic animals (2—5), in which ceramide 2-aminoethylphosphonate (CAEP), a sphingo-phosphonolipid, was later found by ROUSER et al. (6) and characterized by the present authors (4). This phosphonolipid has been found to be so widely distributed in mollusca and protozoa (7) that compounds containing C-P bond are by no means uncommon in nature. There is sufficient evidence for the fact that N-methyl derivatives of AEP, i.e., 2-mono-methylaminoethylphosphonic acid (MMAEP), 2-dimethylaminoethylphosphonic acid and trimethyl-2-phosphonoethylammonium hydro-xide, are present in Colenterata (<9), but the occurrence of their lipid types is still uncer-tain*. * HAYASHI et al. (9) reported the possible oc-currence of CMMAEP in the turbo shellfish (at th