PMID-sentid Pub_year Sent_text comp_official_name comp_offsetprotein_name organism prot_offset 772211-2 1976 These reactive 1,3-dipoles undergo 1,3-dipolar cycloadditions with various dipolarophiles to give C-3 heterocyclic-substituted cephems. 1,3-dipoles 15-26 complement C3 Homo sapiens 98-101