11. Then I looked it up, and its also called Cinnamic acid, which is readily availible commercially. 12. Reduction of the carboxylic acid functional groups in the cinnamic acids provides the corresponding aldehydes, such as cinnamaldehyde. 13. Only a few identified compounds, such as anigorufone and curcumin, use cinnamic acid as their start molecule. 14. Phenylalanine is first converte to cinnamic acid by the action of the enzyme phenylalanine ammonia-lyase ( PAL ). 15. Phenylalanine is first converted to cinnamic acid by the action of the enzyme phenylalanine ammonia-lyase ( PAL ). 16. Phenylalanine is lysated into cinnamic acid, followed by hydroxylation by cinnamate 4-hydroxylase to yield 4-coumaric acid. 17. "' 3, 4-Dimethoxycinnamic acid "'is a cinnamic acid derivative isolated from coffee beans. 18. His investigations in the aromatic series include isomerism of the cinnamic acids and the synthesis of tyrosine from phenylalanine ( 1882 ). 19. He then confirmed this assumption by reacting diethyl malonate and the ethyl ester of cinnamic acid forming the very first Michael adduct: 20. Some resins when soft are known as'oleoresins', and when containing benzoic acid or cinnamic acid they are called balsams.