SEARCH Articles Figures Tables 9-Thiourea Cinchona alkaloid A cinchona alkaloids Alkaloid derivatives Cinchona Cinchona alkaloid derivatives Cinchona alkaloid squaramide Cinchona alkaloid thioureas Cinchona derivatives Cinchona thiourea derivatives Derivative function Function derived Guanidine derivatives Guanidine-derived alkaloids Guanidines thioureas Squaramides Sulfonamides cinchona Sulfonamides functionalities Thiourea cinchona Thiourea functionalities Urea derivatives Urea functionality With guanidine With thiourea With urea With urea derivatives