Phenolic acids are usually divided into two main groups: benzoic acids, containing seven carbon atoms (C6-C1), and cinnamic acids, comprising nine carbon atoms (C6-C3). These compounds exist predominantly as hydroxybenzoic and hydroxycinnamic acids and may occur either in their free or conjugated forms.
Hydroxycinnamic acid and its derivatives (ferulic, caffeic, sinapic, and p-coumaric acids) are a group of compounds highly abundant in food found mainly in cereals, fruits (currants, blueberries and sweet cherries), vegetables, and seeds of fruits. Hydroxycinnamic acids have gained an increasing interest in health because they are known to be potent antioxidants. They are also serving as precursor molecules for the stilbenes, chalcons, flavonoids, lignans, and anthocyanins.
Cinnamic acids have been categorized as structural and functional constituents of plant cell walls and also as bioactive ingredients of the diet. Recent data support their beneficial application as preventive and/or therapeutic agents in several oxidative stress related diseases, such as atherosclerosis, inflammatory injury, and cancer.1
Most of the hydroxycinnamic acid derivatives are effective against fat deposition and lowered plasma lipid profile and increases fat metabolism in liver. Ferulic acid, a hydroxycinnamic acid derivate having antioxidant, anti-inflammatory, anticancer, antiapoptotic, antidiabetic, and hepatoprotective properties that also protects against cerebral ischemia-induced brain damage, improves β-amyloid–induced memory impairment. Ferulic acid can cross the blood–brain barrier and enter the brain by rapid kinetics. It also effectively suppresses blood glucose by elevating glucokinase activity and production of glycogen in the liver and increases plasma insulin levels in diabetic animals.2,3
Caffeic acid can be found in many fruits such as apple, plum, tomato, and grape. Chlorogenic and caffeic acids are two coffee phenolic compounds that exert antioxidant activities, although caffeic acid is more potent than chlorogenic acid.
- Hydroxycinnamic Acid Antioxidants: An Electrochemical Overview. José Teixeira, 1 Alexandra Gaspar, 1 E. Manuela Garrido, 1 , 2 Jorge Garrido, 1 , 2 ,* and Fernanda Borges 1 Biomed Res Int. 2013; 2013: 251754.
- Hydroxycinnamic acid derivatives: a potential class of natural compounds for the management of lipid metabolism and obesity. Md Ashraful Alam, Nusrat Subhan, Hemayet Hossain, Murad Hossain, Hasan Mahmud Reza, Md Mahbubur Rahman, M Obayed Ullah Nutr Metab (Lond) 2016; 13: 27.
- Ferulic Acid Suppresses Glutamate Release Through Inhibition of Voltage-Dependent Calcium Entry in Rat Cerebrocortical Nerve Terminals. Tzu Yu Lin,1,2 Cheng Wei Lu,1 Shu-Kuei Huang,1 and Su-Jane Wangcorresponding author3,4 J Med FoodPMC3576904