Goitrogenic compounds

Another goitrogenic compound in cabbage is thiocyanate ion (107) which results from breakdown of indolylmethyl isothiocyanate produced from the corresponding glucosinolate, glucobrassicin (97,106,108) (reaction G). The 5-hydroxymethylindole thus produced can dimerize to 3,3 -diindolylmethane or form a complex (ascorbigen) with ascorbic acid (perhaps a novel type of feedback inhibition of ascorbate-dependent... 

Plant pigments other than carotenoids and antho-cyanins, e. g., chlorophyll and betalains, are also of great importance in vegetables and are covered in this section together with goitrogenic compounds occurring in Brassicaceae. 

There are 3-15 mg/kg of 5-vinyloxazolidine-2-thione in sliced turnips. Direct intake of thiooxazolidones by humans is unlikely since the vegetable is generally consumed in cooked form. Consequently, the myrosinase enzyme is inactivated and there is no release of goitrogenic compounds. However, brussels sprouts are exceptions, as higher amounts (70-110 mg/kg) of bitter tasting goitrin is formed from progoitrin... 

Aromatic Amines and Phenols. The discovery that sulfaguanidine [57-67-0] was goitrogenic to rats was serendipitous. Many related compounds were then examined, and the aniline moiety was usually present (2,6). Such compounds, as well as resorcinol-like phenols, may act as goitrogens by inhibiting thyroid peroxidases. These are not used clinically. 

There is sufficient evidence for the carcinogenicity of ETU in experimental animals (refs. l8la,b). Given ETU in the diet, rats developed thyroid cancers and liver neoplasms (ref. l8lb). The compound is also a known goitrogen. 

McGinty DA, Bywater WG (1945) Antithyroid studies. I. The goitrogenic activity of some thioureas, pyrimidines and miscellaneous compounds. J Pharmacol Exp Ther 84 342-357... 

The main toxicological concern about this class of compounds is their breakdown to the goitrogen ethylene thiourea (ETU), a potent animal carcinogen (29). Testing for ETU in groundwater is presently being conducted. 

Langer P, Michajlovskij N. Effect of naturally occurring goitrogens on thyroid peroxidase and influence of some compounds on iodide formation during the estimation. Endocrinol Exp 1972 6 97-103. 

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