4-hydroxybenzyl isothiocyanate occurs as a degradation product of sinalbin or glucosinalbin in white mustard.

[1][2][3] In the presence of a nitrile-specifier protein, the less toxic 4-hydroxyphenylacetonitrile is formed from the mustard oil glycoside instead.

The cabbage butterfly exploits this mechanism to avoid the toxic effects of the isothiocyanate.

[2] Similar to other isothiocyanates found in cruciferous vegetables, this compound contributes to the pungent flavor of mustard.

[3] Similar to its natural formation, 4-hydroxybenzyl isothiocyanate can be synthesized by reacting sinalbin with myrosinase.