Water soluble analogues of the anti-inflammatory compound, bis(2-aminopropyl)disulfide dihydrochloride (compd. I) with a butyl (II), phenyl (III), benzyl (IV) or pyrrolidinyl group (V) instead of the methyl group were synthesized, and their effects on the functions of cells related to inflammation were studied in vitro. Compounds II, III and IV showed much higher inhibitory activity than compd. I on formyl Met-Leu-Phe (FMLP)-induced O<SUP>-</SUP><SUB>2</SUB>-generation of polymorphonuclear leukocytes (PMNs) and platelet aggregation. Compound II showed the strongest activity among the compounds (IC<SUB>50</SUB> values : 2.6μM). The inhibition of O<SUP>-</SUP><SUB>2</SUB>-generation of PMNs by compd. II was the most effective when FMLP was used as a stimulant rather than when phorbol myristate acetate, A-23187 and opsonized zymosan were used. However, compd. II was not an O<SUP>-</SUP><SUB>2</SUB>-scavenger.Compounds II, III and IV significantly inhibited a series of activation processes in PMNs, chemotaxis, phagocytosis and lysosomal enzyme release at doses ranging from 10 to 100μM. Under these doses, compds II, III and IV did not affect the histamine release from mast cells or the hemolysis of erythrocytes. These results strongly suggest that the anti-inflammatory action caused by compd. II and its analogues was at least partly due to inhibition of several functions of PMNs and platelets.