beta-Gal-(1->3)-beta-GalNAc-(1->4)-[alpha-Neu5Ac-(2->8)-alpha-Neu5Ac-(2->3)]-beta-Gal-(1->4)-beta-Glc-(1<->1')-Cer 1(II''),9(II')-lactone
beta-gal-(1->3)-beta-galnac-(1->4)-[alpha-neu5ac-(2->8)-alpha-neu5ac-(2->3)]-beta-gal-(1->4)-beta-glc-(1<->1')-cer 1(ii''),9(ii')-lactone
A sialotetraosylceramide consisting of the disialoganglioside GD1b with a lactone ring formed between the two NeuNac residues (between C-1 of the most terminal one and C-9 of the more proximal one).