2.1.1 Para-Coumaric Acid
Synonym p-Hydroxycinnamic acid.
Chemical Structure
Biological Sources It is present in a variety of medicinal plant, namely: Aloe barbadensis Mill. (Liliaceae)-Barbados Aloe, Mediterranean Aloe, Curaeao Aloe; Euphorbia lathyris L. (Euphorbiaceae)-Mole plant, Petroleum plant Caper spurge; Hedra helix L. (Araliaceae)-Ivy; Hura crepitans L. (Euphorbiaceae)-Sandhox Tree; Malus sylvestris Mill. (Rosaceae)-Apple; Melilotus officinalis Lam. (Fabaceae)-Yellow Sweetelover; Trifolium pratense L. (Fabaceae)-Red Clover, Pavine Clover, Cowgrass.
Characteristic Features It occurs as needles having mp 210-213°C. It may be crystallized in its anhydrous form from concentrated hot aqueous solution, but as the monohydrate from dilute aqueous solution on gradual chilling. Its uvmax (in 95% ethanol) are 223 and 286 nm (ε 14,450, 19,000). It is practically insoluble in ligroin and benzene, slightly soluble in cold water, and freely soluble in ethanol, ether and hot water.
