Thiazolidine is a heterocyclic organic compound with a 5-membered saturation ring, a thioether group at position 1, and an amine group at position 3. It is a sulfur analog of oxazolidine. Thiazolidine derivatives are more used than Chemicalbook and have a broad spectrum of biological activity. For example, the drug pioglitazone contains a thiazolidine ring, which is commonly used to lower blood sugar in patients with type 2 diabetes. It can also lower blood pressure and increase HDL levels