Thioamides (rarely, thionamide) are a group of organic compounds that share a common functional group with the general structure R1-CS-NR2R3. One of the best ways of making thioamides is the reaction of an amide with Lawesson's reagent.
Incorporation of thioamides into peptides are used as isosters for the amide bond. Peptide modifications are interesting analogoues of the native peptide, which can reveal the structure-activity-relationship (SAR). Analogoues of peptides can also be used as drugs with an improved oral bioavailability.
Mechanism of action
They inhibit the enzyme thyroid peroxidase in the thyroid, reducing the synthesis of triiodothyronine (T3) and thyroxine (T4); block uptake of iodotyrosines from the colloid. They also block iodine release from peripheral hormone. Maximum effects occur only after a month since hormone depletion is caused by reduced synthesis, which is a slow process.
It penetrates the placental barrier, thus caution is advised when used during pregnancy.
10% of patients report:
0.03% of all patients develop agranulocytosis, a dangerous side-effect.