| 主权项 |
1. A compound of the formula: or a pharmaceutically acceptable salt thereof, wherein
A1 is β-Nal; o-X-Phe, where X is H, OH, CH3, halo, OCH3, NH2, CN, or NO2; p-X-Phe, where X is H, OH CH3, halo, OCH3, NH2, CN, or NO2; m-X-Phe, where X is H, OH CH3, halo, OCH3, NH2, CN, or NO2; F5-Phe; Trp; Dip; 2-Pal; Tyr(Bzl); His; Igl; Tyr(I); Bta; Bip; Npa; or Pal;A3 is Pal, 2-Pal, or 4-Pal;A6 is Thr, Ser, Tle, Thr(Bzl), Abu, Ala, Ile, Leu, Gly, Nle, β-Ala, Gaba, or Val;A8 is a D- or L-isomer of Thr; F5-Phe; p-X-Phe, where X is H, OH, CH3, halo, OCH3, NH2, CN, or NO2; o-X-Phe, where X is H, OH, CH3, halo, OCH3, NH2, CN, or NO2; m-X-Phe, where X is H, OH, CH3, halo, OCH3, NH2, CN, or NO2; Igl; Tyr(Bzl); or β-Nal;each of R1 and R2 is, independently, H or substituted or unsubstituted lower alkyl, aryl, aryl lower alkyl, heterocycle, heterocycle lower alkyl, E1SO2 or E1CO, where E1 is aryl, aryl lower alkyl, heterocycle or heterocycle lower alkyl; wherein said substituent is halo, lower alkyl, hydroxy, halo lower alkyl, or hydroxy lower alkyl;R3 is OH, NH2, C1-12 alkoxy or NH—Y—CH2—Z, wherein Y is a C1-12 hydrocarbon moiety and Z is H, OH, CO2H or CONH2; or R3, together with the carbonyl group of A8 attached thereto, are reduced to form H, lower alkyl, or hydroxy lower alkyl; anda disulfide bond links the sidechains of A2 and A7; provided that if A6 is Thr or Val, then A8 is β-Nal. |
