There are provided peptides of the formula X-Val-Pro-Leu-Gly-Trp-A-Y wherein X represents a hydrogen atom or a terminal nitrogen protecting group, A represents a neutral L-.alpha.-amino acid residue and Y represents OH, NH.sub.2 or a group of the formula OR, NHR, NR.sub.2 or NHNHR' wherein R represents a C.sub.1 -C.sub.11 alkyl group optionally substituted, a C.sub.7 -C.sub.14 aralkyl or a phenyl group and R' represents H, any of the groups which R may represent or a protecting group. Pharmaceutically or veterinarily acceptable salt of these peptides are also provided, as are pharmaceutical or veterinary compositions containing peptides or their salts. The peptides which can be prepared by classical solution synthesis, display useful activity on the central nervous system and are active as growth promotors.
提供了公式为X-Val-Pro-Leu-Gly-Trp-A-Y的肽,其中X表示
氢原子或末端
氮保护基,A表示中性L-.alpha.-
氨基酸残基,Y表示OH,NH.sub.2或公式OR,NHR,NR.sub.2或NHNHR'的基团,其中R表示C.sub.1-C.sub.11烷基,可选地取代,C.sub.7-C.sub.14芳基烷基或
苯基,R'表示H,R可能代表的任何基团或保护基。还提供了这些肽的药学或兽医可接受的盐,以及含有肽或其盐的药物或兽医组合物。这些肽可以通过经典溶液合成制备,并在中枢神经系统上显示有用的活性,并作为生长
促进剂活性。