The title compound, C(22)H(27)N(3)O(10)S, was synthesized by reaction of an ethanol solution of helicid (systematic name: 4-formylphenl-β-d-allopyranoside), thio-semicarbazide and acetic acid. The mol-ecule exhibits a trans conformation with respect to the C=N double bond. The pyran ring adopts a chair conformation. In the crystal structure, the mol-ecules are linked into chains parallel to the b axis by inter-molecular N-H⋯O hydrogen bonds.