Cyclo(-Gly-Ile-Cys-Arg-Cys-Ile-Cys-Gly-Arg-Gly-Ile-Cys-Arg-Cys-Ile-Cys-Gly-Arg) Trifluoroacetate (Disulfide bonds between Cys³ and Cys¹⁶/Cys⁵ and Cys¹⁴/Cys⁷ and Cys¹²)