4-Ser-deaminotocinoic acid 53032-99-8 Deaminotocinoic acid, ser(4)- Deaminotocinoic acid, serine(4)- N-(3-Mercapto-1-oxopropyl)-L-tyrosyl-L-isoleucyl- L-seryl-L-asparaginyl-L-cysteine, cyclic (1-5)- disulfide