Many bioactive compounds in ginger have been identified, such as phenolic and terpene compounds. The phenolic compounds are mainly gingerols, shogaols, and paradols, which account for the various bioactivities of ginger.
In fresh ginger, gingerols are the major polyphenols, such as 6-gingerol, 8-gingerol, and 10-gingerol. 6-gingerol is a major pungent ingredient of ginger.
It is formed in the plant from phenylalanine, malonate, and hexonate. In the fresh ginger rhizome, the gingerols were identified as the main active components, and gingerol [5-hydroxy-1-(4-hydroxy-3-methoxyphenyl) decan-3-one] is the most abundant constituent in the gingerol series.
Gingerols are biologically active components that may make a significant contribution towards medicinal applications of ginger. Gingerol, however, are thermally labile due to the presence of ß-hydroxy keto group and are converted under high temperature to [6]-, [8]-, and [10]-shogaols.
In vitro and in vivo studies have demonstrated that ginger and its bioactive compounds 6-gingerol possess strong antioxidant activity.
Gingerols in ginger
