An emerging platform from renewable resources: selection guidelines for human exposure of furfural-related compounds

5-Hydroxymethylfurfural (HMF) is a precursor for the synthesis of potential chemical building blocks and biofuel products. Therefore, it is expected to be a very important bioplatform player in the future due to reduction of fossil resources. Controversial data exist about HMF toxicity and, in addition, toxicological data of its derivatives are scarce. We evaluated the impact of several HMF derivatives in human skin fibroblast cells and data demonstrate that the dialdehyde (10), dihydroxymethyl (12), dimethyl (18) and the dimer (20) derivatives are potentially more harmful than the dicarboxylic acid derivative (17). HMF was not cytotoxic whereas the reported derivative 5-sulfoxymethylfurfural (SMF) was weakly cytotoxic. Some examples of derivatives are presented which are considerably more toxic than SMF.