p-Coumaric Acid: A Naturally Occurring Chemical with Potential Therapeutic Applications

Coumaric acid is a hydroxy derivative of cinnamic acid with three different isomers (ortho, meta and para). Its most commonly available form is p-coumaric acid. p-Coumaric acid i.e., 4-hydroxycinnamic acid is a potent phenolic compound found to exist naturally in various plants, cereals, fruits and vegetables. It is one of the major constituent compounds of phenolic polymer lignin in lignocellulosic materials. Various natural and synthetic derivatives of pcoumaric acid have been reported in the literature. Different extraction methods including conventional methods such as solvent extraction, acidification, alkaline extraction etc. and recent approaches such as the clip-off method, sugaring out method, soft microwave extraction etc. for its qualitative and quantitative determination in various plant materials have been investigated by various researchers. This paper has discussed the synthesis of various derivatives of p-coumaric acid such as amides, esters, aldehydes, polymers, and copolymers. p-Coumaric acid and its derivatives have been found to possess different bioactive properties such as antioxidant, antimicrobial, anticancer, antiarthritic, anti-inflammatory, gout prevention, anti-diabetic, anti-melanogenic, skin regeneration, gastroprotective, anti-ulcer, cardioprotective, hepatoprotective, reno-protective, bone formation, anti-angiogenic and anti-platelet etc. Owing to this huge bioactive potential, p-coumaric acid could be incorporated in edible food products, pharmaceutical products, cosmetics, etc. More studies are required to evaluate their compatability in these products. To the best of our knowledge, this is the first review discussing natural occurrence, extraction, natural derivatives, synthesis of various derivatives and therapeutic applications of p-coumaric acid.