Short chemical syntheses were developed to produce a new set of surfactants from uronic acids derived from widely available raw materials. Three different strategies were used to synthesize uronic amide derivatives, the structures of which were totally characterized by spectrometric methods (IR, MS, 1 H-RMN and 13 C-RMN). The best one, using an acid chloride as the synthetic intermediate, furnished the expected amides as a mixture of anomers in 46-58% global yield. Surface-active properties (CMC, c cmc , C max , A min ) of homologous series of uronic acid N-alkylamides from C8 to C18 were also assessed. In general, these sugar-based surfactants exhibited good surface-activities, and appeared as valuable nonionic surfactants compared to octylphenol 9-10 ethylene oxide condensate, the most well-known nonionic surfactant. Increasing the alkyl chain length influenced the CMC values for both glucuronic and galacturonic N-alkylamide derivatives. The galacturonic N-alkylamides decreased c cmc at slower values than their counterpart's glucuronic N-alkylamides.
AbbreviationsCOSY Correlation spectroscopy DCC Dicyclohexyl carbodiimide DMF Dimethyl formamide DMSO Dimethyl sulfoxide ESIMS Electrospray ionisation mass spectrometry HMBC Heteronuclear multiple bond correlation HSQC Heteronuclear single quantum correlation NOESY Nuclear Overhauser effect spectroscopy TLC Thin layer chromatography TMS Tetramethylsilane