Goitrin is a sulfur-containing oxazolidine

Oxazolidine

Oxazolidine is a five-membered ring compound consisting of three carbons, a nitrogen, a hydrogen, and an oxygen. The oxygen and NH are the 1 and 3 positions, respectively. In oxazolidine derivatives, there is always a carbon between the oxygen and the nitrogen . All of the carbons in oxazolidines...

, a cyclic thiocarbamate

Thiocarbamate

Thiocarbamates are a family of organosulfur compounds. There are two isomeric forms of thiocarbamate esters: O-thiocarbamates, ROCNR2, and S-thiocarbamates, RSCNR2...

, that reduces the production of thyroid hormone

Thyroid hormone

The thyroid hormones, thyroxine and triiodothyronine , are tyrosine-based hormones produced by the thyroid gland primarily responsible for regulation of metabolism. An important component in the synthesis of thyroid hormones is iodine. The major form of thyroid hormone in the blood is thyroxine ,...

s such as thyroxine

Thyroxine

Thyroxine, or 3,5,3',5'-tetraiodothyronine , a form of thyroid hormones, is the major hormone secreted by the follicular cells of the thyroid gland.-Synthesis and regulation:...

. It is found in cruciferous vegetables such as cabbage

Cabbage

Cabbage is a popular cultivar of the species Brassica oleracea Linne of the Family Brassicaceae and is a leafy green vegetable...

, brussels sprout

Brussels sprout

The Brussels sprout is a cultivar of wild cabbage grown for its edible buds. The leafy green vegetables are typically 2.5–4 cm in diameter and look like miniature cabbages. The sprout is Brassica oleracea, in the "gemmifera" group of the family Brassicaceae...

s and oil-seed rape, and is formed by the hydrolysis of a glucosinolate

Glucosinolate

The glucosinolates are a class of organic compounds that contain sulfur and nitrogen and are derived from glucose and an amino acid. They occur as secondary metabolites of almost all plants of the order Brassicales , but also in the genus Drypetes .-Chemistry:Glucosinolates are water-soluble...

; 2-hydroxy-3-butenyl glucosinolate. The unstable isothiocyanate (2-hydroxy-3-butenyl isothiocyanate) derived from the latter glucosinolate spontaneously cyclizes to goitrin, because the hydroxy group is situated in proximity to the isothiocyanate group (allowing a five-membered ring to be formed). Hence, the oxygen in the molecule stems from the hydroxy group of the original unstable isothiocyanate. Plants containing this specific glucosinolate (or glucosinolates such as glucobrassicin

Glucobrassicin

Glucobrassicin is a type of glucosinolate that can be found in almost all cruciferous plants, such as cabbages , mustards, cress, and woad. As for other glucosinolates, degradation by the enzyme myrosinase is expected to produce an isothiocyanate, indol-3-ylmethylisothiocyanate...

 and sinalbin

Sinalbin

Sinalbin is a glucosinolate found in the seeds of white mustard, Sinapis alba, and in many wild plant species. In contrast to mustard from black mustard seeds which contain sinigrin, mustard from white mustard seeds has only a weakly pungent taste.The less sharp taste is because the mustard oil...

 which liberate thiocyanate ion) have goitrogenic

Goitrogen

Goitrogens are substances that suppress the function of the thyroid gland by interfering with iodine uptake, which can, as a result, cause an enlargement of the thyroid, i.e., a goitre.-Goitrogenic drugs and chemicals:...

potential due to the goitrin and thiocyanate they contain. However, they do not seem to alter thyroid function in humans at realistic amounts in the diet.