label: an alpha-Neu5Ac-(2->3)-beta-D-Gal-(1->3)-D-GlcNAc derivative + CMP-N-acetyl-beta-neuraminate => an alpha-Neu5Ac-(2->3)-beta-D-Gal-(1->3)-[alpha-Neu5Ac-(2->6)]-D-GlcNAc-R + CMP + H(+)
label_lc: an alpha-neu5ac-(2->3)-beta-d-gal-(1->3)-d-glcnac derivative + cmp-n-acetyl-beta-neuraminate => an alpha-neu5ac-(2->3)-beta-d-gal-(1->3)-[alpha-neu5ac-(2->6)]-d-glcnac-r + cmp + h(+)