Sinalbin is a glucosinolate found in the seeds of white mustard, Sinapis alba, and in many wild plant species.

[1] Sinalbin is metabolised to form the mustard oil 4-hydroxybenzyl isothiocyanate by the enzyme myrosinase.

The less sharp taste of white mustard is because 4-hydroxybenzyl isothiocyanate is unstable and degrades to 4-hydroxybenzyl alcohol and a thiocyanate ion, which are not pungent.

The half-life of the isothiocyanate depends on the pH of the solution – the longest time is 321 minutes at pH 3, and the shortest is 6 minutes at pH 6.5.

[2] Glucobrassicin is a structurally related glucosinolate that likewise yields a non-pungent isothiocyanate due to reaction with water.