Synthesis of Some Phenylpropanoid Monoglycerides via the Mitsunobu Protocol

Natural monoglycerides of cinnamic, ferulic and p-coumaric acids were synthesized in good to high overall yields from isopropylidene glycerol via the Mitsunobu reaction and further deprotection of the corresponding acetonides with Amberlyst 15. The method avoids the need of protection of the phenolic hydroxyls. During the Mitsunobu esterifications a strong influence of the acid strength on the efficacy and outcome of the reaction was observed

Original scientific paper

Seasonal variations in the leaf surface composition o

Evaluation of the radical scavenging activity of a series of synthetic hydroxychalcones towards the DPPH radical

Sixteen hydroxychalcones were synthesized in sufficient purity by the Claisen–Schmidt condensation between appropriate acetophenones and aromatic aldehydes. All the compounds were evaluated for their ability to scavenge the stable free 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical. Important structure–activity relationships were observed that strongly contribute to the knowledge for the design of DPPH radical scavenging chalcones. Relevant theoretical parameters were computed in an attempt to understand and explain the obtained experimental results

Original enzyme-catalyzed synthesis of chalcones: Utilization of hydrolase promiscuity

E-chalcone was obtained with very high stereoselectivity for the first time by an enzyme-catalyzed Claisen-Schmidt condensation between benzaldehyde and acetophenone. From a set of lipases, only that from hog pancreas demonstrated promiscuity, catalyzing the reaction in the presence of imidazole as a promoter. Another enzyme, acylase from Aspergillus melleus (3.5.1.14) also proved to be active in the synthesis of E-chalcone under the same reaction conditions. This acylase along with the recombinant D-aminoacylase (3.5.1.81) catalyzed also the reaction between acetophenone and p-nitrobenzaldehyde. Such “green” approach to synthesis of chalcones is of great interest, because of their important applications as formula ingredients in pharmaceutical, food and cosmetic industry