Abstract
In this study, starch (1) was oxidized to starch-2,3-dialdehyde (DAS; 2) using potassium periodate. In addition, two novel Schiff's bases (5 & 6) were synthesized via a condensation reaction between DAS (2) and sulfa drugs (sulfanilamide; 3 & sulfathiazole; 4). The synthesized Schiff's bases (5 & 6) were characterized by FT-IR spectroscopy, X-ray diffraction and DSC analysis. DAS can easily be oxidized owing to its high aldehyde content (91.0%). However, it has low reactivity towards sulfanilamide (3) and sulfathiazole (4). According to the diffraction functional theory, this peculiar behavior is caused by the absence of V-shape in alpha-glucan linkage in DAS molecules, making the carbonyl group least electropositive. This reduces the nucleophilic attacks of the amino group in sulfa drugs towards the carbonyl group in DAS. (C) 2016 Elsevier Ltd. All rights reserved.