Tripeptides of the general formula: ##STR1## wherein the symbols R, which may be the same or different represent hydrogen or a fatty acid residue (at least one of them representing a fatty acid residue), R.sub.1 represents hydroxy, amino or alkoxy and R.sub.2 and R.sub.3, which may be the same or different, represent hydrogen, carboxy, carbamoyl or alkoxycarbonyl radical (with the proviso that R.sub.2 and R.sub.3 cannot simultaneously represent a hydrogen atom), the alanine moiety being in the L form, the glutamic acid moiety being in the D form, the lysine moiety (when R.sub.2 or R.sub.3 =a hydrogen atom) being in the L form and the 2,6-diaminopimelic acid moiety or its derivatives (when R.sub.2 and/or R.sub.3 =carboxy, carbamoyl or alkoxycarbonyl) being in the D,D, L,L, D,D/L,L (racemic) or D,L (meso) form, and salts thereof, possess immunological adjuvant and immunostimulant activity.
                            通式为:##STR1## 的三肽,其中符号 R 可以是相同或不同的氢或
脂肪酸残基(其中至少一个表示
脂肪酸残基),R.sub.1 表示羟基、
氨基或烷氧基,R.sub.2 和 R.sub.3 可以是相同或不同的氢、羧基、
氨基甲酰基或烷氧羰基基团(条件是 R.sub.2 和 R.sub.3 不能同时表示氢原子),丙
氨酸基团为 L 形,谷
氨酸基团为 D 形,赖
氨酸基团(当 R.sub.2 或 R.sub.3 = 氢原子时)为 L 形,
2,6-二氨基庚二酸基团或其衍
生物(当 R.sub.2 和/或 R.sub.3 = 羧基、
氨基甲酰基或烷氧羰基时)为 D,D,L,L,D,D/L,L(外消旋)或 D,L(内消旋)形式,以及其盐,具有免疫佐剂和免疫刺激活性。