Shogaols are

pungent Pungency () refers to the taste of food commonly referred to as spiciness, hotness or heat, found in foods such as chili peppers. Highly pungent tastes may be experienced as unpleasant. The term piquancy () is sometimes applied to foods with a l ...

constituents 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 ...

similar in chemical structure to

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 ...

. The most common of the group is shogaol. Like zingerone, it is produced when ginger is dried or cooked. Moreover, shogaol (and

) are converted to other constituents when heat is applied over time, which is why ginger loses its spiciness as it is cooked. The name ''shogaol'' is derived from the

Japanese Japanese may refer to: * Something from or related to Japan, an island country in East Asia * Japanese language, spoken mainly in Japan * Japanese people, the ethnic group that identifies with Japan through ancestry or culture ** Japanese diaspor ...

name for ginger (生姜、''shōga''). Shogaol is rated 160,000 SHU on the

Scoville scale The Scoville scale is a measurement of the pungency (spiciness or "heat") of chili peppers, as recorded in Scoville heat units (SHU), based on the concentration of capsaicinoids, among which capsaicin is the predominant component. The scale i ...

. When compared to other pungent compounds, shogaol is moderately more pungent than

piperine Piperine, along with its isomer chavicine, is the alkaloid responsible for the pungency of black pepper and long pepper. It has been used in some forms of traditional medicine. Preparation Due to its poor solubility in water, piperine is typi ...

, but less than

capsaicin Capsaicin (8-methyl-''N''-vanillyl-6-nonenamide) ( or ) is an active component of chili peppers, which are plants belonging to the genus ''Capsicum''. It is a chemical irritant for mammals, including humans, and produces a sensation of burnin ...

Shogaols group

Shogaol, shogaol, 0shogaol, and 2shogaol (all found in ginger) together constitute the group shogaols. There also exist in ginger cultivars methylated shogaols: methyl shogaol and methyl shogaol, respectively. Shogaols are artifacts formed during storage or through excess heat, probably created by a

dehydration reaction In chemistry, a dehydration reaction is a chemical reaction that involves the loss of water from the reacting molecule or ion. Dehydration reactions are common processes, the reverse of a hydration reaction. Dehydration reactions in organic ch ...

of the gingerols. The ratio of shogaols to gingerols sometimes is taken as an indication of product quality.

NSF International NSF (an initialism for National Sanitation Foundation) is a product testing, inspection, certification organization with headquarters in Ann Arbor, Michigan. NSF also offers consulting and training services worldwide. History NSF Internatio ...

''Determination of Gingerols and Shogaols in Zingiber officinale rhizome and powdered extract by High-Performance Liquid Chromatography''

Synthesis

A possible synthesis starts with a

Claisen condensation The Claisen condensation is a carbon–carbon bond forming reaction that occurs between two esters or one ester and another carbonyl compound in the presence of a strong base, resulting in a β-keto ester or a β-diketone. It is named after Ra ...

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

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 ...

, producing dehydrozingerone. Afterwards the product reacts in an

aldol condensation An aldol condensation is a condensation reaction in organic chemistry in which two carbonyl moieties (of aldehydes or ketones) react to form a β-hydroxyaldehyde or β-hydroxyketone (an aldol reaction), and this is then followed by dehydration to ...

with

hexanal Hexanal, also called hexanaldehyde or caproaldehyde is an alkyl aldehyde used in the flavor industry to produce fruity flavors. Its scent resembles freshly cut grass, like ''cis''-3-hexenal. It is potentially useful as a natural extract that pre ...

in tetrahydrofurane to 6-dehydroshogaol and 6-dehydrogingerol. Latter can be

hydrogenated 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 ...

to gingerol by a catalyst. In the last step

hydrochloric acid Hydrochloric acid, also known as muriatic acid, is an aqueous solution of hydrogen chloride. It is a colorless solution with a distinctive pungent smell. It is classified as a strong acid. It is a component of the gastric acid in the dige ...

is added to get the desired shogaol. Wikipedia-shogaol

References

{{Transient receptor potential channel modulators Pungent flavors O-methylated natural phenols Ginger