Zingerone, also called vanillylacetone, is a major flavor component of

ginger Ginger (''Zingiber officinale'') is a flowering plant whose rhizome, ginger root or ginger, is widely used as a spice and a folk medicine. It is a herbaceous perennial which grows annual pseudostems (false stems made of the rolled bases of ...

, providing the sweet flavor of cooked ginger. Zingerone is a crystalline solid that is sparingly soluble in water and soluble in ether. Zingerone is similar in chemical structure to other flavor chemicals such as

vanillin Vanillin is an organic compound with the molecular formula . It is a phenolic aldehyde. Its functional groups include aldehyde, hydroxyl, and ether. It is the primary component of the extract of the vanilla bean. Synthetic vanillin is now u ...

and

eugenol Eugenol is an allyl chain-substituted guaiacol, a member of the allylbenzene class of chemical compounds. It is a colorless to pale yellow, aromatic oily liquid extracted from certain essential oils especially from clove, nutmeg, cinnamon, bas ...

. It is used as a flavor additive in spice oils and in perfumery to introduce spicy aromas. Fresh ginger does not contain zingerone, but it is produced by cooking or drying of the ginger root, which causes a reverse aldol reaction on

gingerol Gingerol ( gingerol) is a phenolic phytochemical compound found in fresh ginger that activates spice receptors on the tongue. It is normally found as a pungent yellow oil in the ginger rhizome, but can also form a low-melting crystalline solid. T ...

Production

History

Zingerone was first isolated from the ginger root in 1917 by Hiroshi Nomura, a chemistry professor at

Tokyo Imperial University , abbreviated as or UTokyo, is a public research university located in Bunkyō, Tokyo, Japan. Established in 1877, the university was the first Imperial University and is currently a Top Type university of the Top Global University Project by ...

. Nomura named the compound and identified the empirical formula of zingerone in his studies at the laboratory of the Agricultural College. He initially identified it as the chemical component contributing pungency to ginger, something further work has disproven.

Current methods

Nomura identified and later patented a method for the synthesis of zingerone, in which vanillin and

acetone Acetone (2-propanone or dimethyl ketone), is an organic compound with the formula . It is the simplest and smallest ketone (). It is a colorless, highly volatile and flammable liquid with a characteristic pungent odour. Acetone is miscibl ...

are reacted under basic conditions to form dehydrozingerone. This compound is obtained in about 95% quantity. This reaction is followed by

catalytic hydrogenation Hydrogenation is a chemical reaction between molecular hydrogen (H2) and another compound or element, usually in the presence of a catalyst such as nickel, palladium or platinum. The process is commonly employed to reduce or saturate organic ...

of the intermediate compound in order to form zingerone, obtained in approximately 100% quantity.

Biological effects

Ginger compounds have been shown to be active against enterotoxigenic ''

Escherichia coli ''Escherichia coli'' (),Wells, J. C. (2000) Longman Pronunciation Dictionary. Harlow ngland Pearson Education Ltd. also known as ''E. coli'' (), is a Gram-negative, facultative anaerobic, rod-shaped, coliform bacterium of the genus '' Esc ...

'' heat-labile enterotoxin-induced diarrhea. This type of diarrhea is the leading cause of infant death in developing countries. Zingerone is likely the active constituent responsible for the antidiarrheal efficacy of ginger. Zingerone is recognized as being a particularly efficient free radical scavenger. It is able to scavenge and degrade

free radicals In chemistry, a radical, also known as a free radical, is an atom, molecule, or ion that has at least one unpaired valence electron. With some exceptions, these unpaired electrons make radicals highly chemically reactive. Many radicals spon ...

and

reactive oxygen species In chemistry, reactive oxygen species (ROS) are highly reactive chemicals formed from diatomic oxygen (). Examples of ROS include peroxides, superoxide, hydroxyl radical, singlet oxygen, and alpha-oxygen. The reduction of molecular oxygen () p ...

in the body, and inhibits enzymes involved in the generation of these reactive oxygen species. It is used by some flowers to attract pollinating fruit flies by mimicking the sex pheromone of the fly. {{Cite journal, last1=Tan, first1=Keng-Hong, last2=Nishida, first2=Ritsuo, date=2007, title=Zingerone in the floral synomone of Bulbophyllum baileyi (Orchidaceae) attracts Bactrocera fruit flies during pollination, journal= Biochemical Systematics and Ecology, volume=35, issue=6 , pages=334–341, doi=10.1016/j.bse.2007.01.013

References

O-methylated natural phenols Pungent flavors Ginger