The design, synthesis and biological evaluation of novel Leonurine-cysteine analog conjugates 3, 5-dimethoxy-4-(2-amino-3-prop-2-ynylsulfanyl-propionyl)-benzoic acid 4- guanidino-butyl ester (1a), 3, 5-dimethoxy-4-(2-animo-3-allysulfanyl-propionyl)-benzoic acid 4-guanidino-butyl ester (1b) and 3, 5-dimethoxy-4-(3-(2-chlorocarbonyl-ethyldisulfanyl)- propionyl)-benzoic acid 4-guanidino-butyl ester (2) were reported in this paper. We tested ...