Ginger compound: Shogaols

Gingerols and shogaols are the chemesthetic compounds found in species from the Zingiber genus, ginger being the most common species. Shogaols, a monodehydrated gingerol was reported to be a pungent component of ginger.

Gingerols, through dehydration, form shogoals. Zingerone, a compound not found in fresh ginger, is formed by a retro-aldol reaction when gingerol is heated.

Usually, the fresh rhizome contains none or very small amounts of shogaols, while the dried rhizome is rich in shogaols. This suggests that shogaols are formed through dehydration during processing or storage of the fresh rhizome.

With formation of shogaols by the dehydration of gingerol, the pungency doubles - which is why aged ginger usually has a stronger bite.

HPLC is by far the most popular technique to separate and detect gingerols and shogaols in ginger.
Ginger compound: Shogaols