Ten analogues derived from oxytocin, deamino-oxytocin and deamino-carba-oxytocin were prepared which contained a D-amino acid in the position 2 of the parent system. The following D-amino acids were introduced: tyrosine, phenylalanine, p-methylphenylalanine, p-ethylphenylalanine and O-ethyltyrosine. Combination of two structural features which alone lead to strong inhibitors (a suitable D-amino acid in position 2 and a penicillamine moiety in position 1) did not enhance the inhibitory effect. Compounds containing D-tyrosine are weak agonists in the uterotonic assay; in case of 1-carba-analogues they can be converted into sulfoxides with low inhibitory activity. Analogues with D-phenylalanine substituted in the para-position are the most potent antagonists of the uterotonic effect of oxytocin (pA2 = 8.73) in vitro.
从催产素、去氨基催产素和去氨基卡巴催产素中制备了十种类似物,其中在母体系统的位置2含有D-氨基酸。引入了以下D-氨基酸:酪氨酸、苯丙氨酸、对甲基苯丙氨酸、对乙基苯丙氨酸和O-乙基酪氨酸。单独引起强抑制剂作用的两种结构特征的组合(位置2中适当的D-氨基酸和位置1中的青霉胺基团)并未增强抑制作用。含有D-酪氨酸的化合物在子宫收缩实验中是弱激动剂;在1-卡巴类似物的情况下,它们可以转化为具有低抑制活性的亚砜。在对位替代D-苯丙氨酸的类似物中,它们是催产素子宫效应最有效的拮抗剂(pA2 = 8.73)体外。