Interaction between hydroquinone and ascorbic acid derivatives: Quenching effect of organic solvents

The interaction between hydroquinone (HQ) and ascorbic acid analogs was inv estigated Semiquinone radicals (SQ .) generated by Ne were comparably scave nged by ascorbic acid, sodium ascorbate and ascorbate 6-palmitate, but much less efficiently by ascorbate 2,6-dipalmitate. Organic solvents, such as d imethysulfoxide (DMSO) or ethanol, which are utilized for solubilization of water-insoluble analogs, ascorbate 6-palmitate and ascorbate 2,6-dipalmita te, also scavenged SQ .. DMSO scavenged the SQ . more efficiently than etha nol. This suggests the importance of considering such a quenching. effect o f organic solvent in the study of the interaction between HQ and antioxidan ts. The involvement of the ascorbate radical for cytotoxicity induction is discussed.