2.7 Thioglycosides
This speicific group of glycosides is also referred to as ‘Thiocynate Glycosides’ or ‘Sulphurated Glycosides’ or ‘Glucosinolate Compounds’ or Isothiocyanate Glycosides’ in various literatures. The aglycone portion of such glycoside essentially contains isothiocynate residue having sulphur plus nitrogen atoms. The general structure originally assigned to these aglycones (Formula A) has now been replaced by a more favourable one (Formula B).
In general, the thioglycosides are specifically abundant in several families, such as: Cruciferae, Capparidaceae and Rosaceae. More tham forty thiocyanate glycosides, having a variety of
configurations in the side chain, have been isolated and identified. In fact, most glycosides belonging to this category invariably comprise of a sulphuric acid residue which on hydrolysis gives rise to a potassium salt resepctively.
The three principal thioglycosides commonly known are as follows: Sinigrin—in Black
Mustards; Sinalbin—in White Mustards; and Gluconapin—in rape seeds. These naturally occurring plant drugs shall be discused individually in the sections that follows.
