Vanillic acid (4-hydroxy-3-methoxybenzoic acid) is a
dihydroxybenzoic acid derivative used as a flavoring agent. It is an
oxidized
Redox (reduction–oxidation, , ) is a type of chemical reaction in which the oxidation states of substrate change. Oxidation is the loss of electrons or an increase in the oxidation state, while reduction is the gain of electrons or a ...
form of
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 ...
. It is also an intermediate in the production of vanillin from
ferulic acid
Ferulic acid is a hydroxycinnamic acid, an organic compound with the formula (CH3O)HOC6H3CH=CHCO2H. The name is derived from the genus ''Ferula'', referring to the giant fennel ('' Ferula communis''). Classified as a phenolic phytochemical, ferul ...
.
Occurrence in nature
The highest amount of vanillic acid in plants known so far is found in the root of ''
Angelica sinensis
''Angelica sinensis'', commonly known as ''dong quai'' () or female ginseng, is a herb belonging to the family Apiaceae, indigenous to China. ''Angelica sinensis'' grows in cool high altitude mountains in East Asia. The yellowish brown root of t ...
'', an herb indigenous to China, which is used in
traditional Chinese medicine
Traditional Chinese medicine (TCM) is an alternative medical practice drawn from traditional medicine in China. It has been described as "fraught with pseudoscience", with the majority of its treatments having no logical mechanism of acti ...
.
Occurrences in food
Açaí oil
Açaí oil is obtained from the fruit of ''Euterpe oleracea'' (açaí palm), which grows in the Amazon rainforest. The oil is rich in phenolic compounds similar in profile to the pulp itself, such as vanillic acid, syringic acid, p-hydroxybenzoi ...
, obtained from the fruit of the açaí palm (''
Euterpe oleracea''), is rich in vanillic acid (). It is one of the main natural phenols in
argan oil. It is also found in
wine
Wine is an alcoholic drink typically made from fermented grapes. Yeast consumes the sugar in the grapes and converts it to ethanol and carbon dioxide, releasing heat in the process. Different varieties of grapes and strains of yeasts are m ...
and
vinegar
Vinegar is an aqueous solution of acetic acid and trace compounds that may include flavorings. Vinegar typically contains 5–8% acetic acid by volume. Usually, the acetic acid is produced by a double fermentation, converting simple sugars to eth ...
.
Metabolism
Vanillic acid is one of the main
catechins
Flavan-3-ols (sometimes referred to as flavanols) are a subgroup of flavonoids. They are derivatives of flavans that possess a 2-phenyl-3,4-dihydro-2''H''-chromen-3-ol skeleton. Flavan-3-ols are structurally diverse and include a range of comp ...
metabolites found in humans after consumption of
green tea infusions.
Synthesis
Oxidation of
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 ...
to the carboxylic acid occurred in ~88% yield.
References
{{Gallotannin
Flavors
Dihydroxybenzoic acids
Gallotannins
Vanilloids
Phenol ethers