(d(CH2)51,Tyr(Me)2,Arg8)-Vasopressin Trifluoroacetate, b-Mercapto-b,b-cyclopentamethylene-propionyl-Tyr(Me)-Phe-Gln-Asn-Cys-Pro-Arg-Gly-NH2, 73168-24-8, C52H74N14O12S2, Mr 1151.38, 1mg. Manning Compound, [Pmp1, Tyr(OMe)2, Arg8] Vasopressin. A very potent V1 receptor antagonist (antivasopressor) with almost no antidiuretic activity.