p-Coumaric acid ethyl ester

Free Radicals & Antioxidants, 2011, 1(1):23-7.

P -Coumaric Acid Ester with Potential Antioxidant Activity from the Genus Salvia[Reference: WebLink]

A phytochemical analysis of the acetone extract of the aerial parts of the plants Salvia splendens and Salvia lanigra yielded a long chain alkyl p-coumaric acid ester; eicosanyl-cis-p-coumarate (1), which has not previously been isolated from Salvia genus, together with two triterpenoids; oleanolic acid (2) and echinocystic acid (3) and two flavonoids; 7-methoxyapigenin (4) and luteolin-7-O-glucoside (5).
METHODS AND RESULTS:
The structures of these compounds were assigned by spectroscopic analysis and comparison with literature data of known compounds. The antioxidant potential of the p-coumaric acid ester (1) was evaluated, in vitro, by using DPPH for free radical scavenging activity.
CONCLUSIONS:
A moderate free radical scavenging ability was observed.

J Agric Food Chem. 2015 Apr 8;63(13):3402-18.

Sensomics analysis of key bitter compounds in the hard resin of hops (Humulus lupulus L.) and their contribution to the bitter profile of Pilsner-type beer.[Pubmed: 25793563]

Recent brewing trials indicated the occurrence of valuable bitter compounds in the hard resin fraction of hop.
METHODS AND RESULTS:
Aiming at the discovery of these compounds, hop's ε-resin was separated by means of a sensory guided fractionation approach and the key taste molecules were identified by means of UV/vis, LC-TOF-MS, and 1D/2D-NMR studies as well as synthetic experiments. Besides a series of literature known xanthohumol derivatives, multifidol glucosides, flavon-3-on glycosides, and p-coumaric acid esters, a total of 11 bitter tastants are reported for the first time, namely, 1",2"-dihydroxanthohumol F, 4'-hydroxytunicatachalcone, isoxantholupon, 1-methoxy-4-prenylphloroglucinol, dihydrocyclohumulohydrochinone, xanthohumols M, N, and P, and isoxanthohumols M, N, and P, respectively. Human sensory analysis revealed low bitter recognition threshold concentrations ranging from 5 (co-multifidol glucopyranoside) to 198 μmol/L (trans-p-Coumaric acid ethyl ester) depending on their chemical structure. For the first time, LC-MS/MS quantitation of these taste compounds in Pilsner-type beer, followed by taste re-engineering experiments, revealed the additive contribution of iso-α-acids and the identified hard resin components to be truly necessary and sufficient for constructing the authentic bitter percept of beer.
CONCLUSIONS:
Finally, brewing trails using the ε-resin as the only hop source impressively demonstrated the possibility to produce beverages strongly enriched with prenylated hop flavonoids.