title: Structure activity relationship of orally active enkephalin analogues as analgesics.
mesh_terms: D000284:Administration, Oral; D000700:Analgesics; D004723:Endorphins / Q000494:pharmacology*; D004745:Enkephalins / Q000008:administration & dosage / Q000494:pharmacology*; D008745:Methylation; D013329:Structure-Activity Relationship
chemical_list: D000700:Analgesics; D004723:Endorphins; D004745:Enkephalins