(2-Quinoxalinecarbonyl)-Thr-Ile-Nle.psi.[COCH2]-(D or L)-Nle-Gln-Arg-NH2 AIDS-082213 AIDS082213 Qui-Thr-Ile-Nle.psi.[COCH2]-(D or L)-Nle-Gln-Arg-NH2