Soxhlet (SE), microwave-assisted (MAE) and ultrasound-assisted (UAE) extraction were compared using ten extraction solvents for their efficiency to extract phenolic and flavonoid antioxidants from Eastern Canada propolis. Extracts were compared for total phenolic (TPC) and total flavonoid (TFC) content, and radical scavenging activities. Anti-inflammatory activity through inhibition of 5-lipoxygenase (5-LO) products biosynthesis in HEK293 cells was also evaluated. The results showed that SE extracts using polar solvents had the highest TPC and TFC. Extracts obtained with ethanol, methanol and acetone were effective free radical scavengers, and showed 5-LO inhibition similar to zileuton. UAE was an effective extraction method since the extracts obtained were comparable to those using SE and the MAE while being done at room temperature. With UAE, extracts of less polar solvents showed similar free radical scavenging and 5-LO inhibition to extracts of much more polar solvents such as methanol or ethanol. Reversed-phase liquid chromatography tandem mass spectrometry confirmed the presence of 21 natural compounds in the propolis extracts based on the comparison of intact mass, chromatographic retention time and fragmentation patterns derived from commercial analytical standards. The current study is the first of its kind to concurrently investigate solvent polarity as well as extraction techniques of propolis.

A novel series of zileuton-hydroxycinnamic acid hybrids were synthesized and screened as 5-lipoxygenase (5-LO) inhibitors in stimulated HEK293 cells and polymorphonuclear leukocytes (PMNL). Zileuton’s (1) benzo[b]thiophene and hydroxyurea subunits combined with hydroxycinnamic acid esters’ ester linkage and phenolic acid moieties were investigated. Compound 28, bearing zileuton’s (1) benzo[b]thiophene and sinapic acid phenethyl ester’s (2) α,β-unsaturated phenolic acid moiety 28, was shown to be equipotent to zileuton (1), the only clinically approved 5-LO inhibitor, in stimulated HEK293 cells. Compound 28 was three times as active as zileuton (1) for the inhibition of 5-LO in PMNL. Compound 37, bearing the same sinapic acid (3,5-dimethoxy-4-hydroxy substitution) moiety as 28, combined with zileuton’s (1) hydroxyurea subunit was inactive. This result shows that the zileuton’s (1) benzo[b]thiophene moiety is essential for the inhibition of 5-LO product biosynthesis with our hydrids. Unlike zileuton (1), Compound 28 formed two π–π interactions with Phe177 and Phe421 as predicted when docked into 5-LO. Compound 28 was the only docked ligand that showed a π–π interaction with Phe177 which may play a part in product specificity as reported.

: The hydroxycinnamic acid scaffold is extremely versatile with various biological activities. This review will highlight the progress of the biological activities of hydroxycinnamic acids and their related synthetic analogs, including recently reported anti-cancer, anti-inflammatory, and antioxidant activities.

Heterogeneous catalysts based on different active metals (Pd, Pt, Ru, and Rh) and supports (carbon and alumina) were systematically tested for hydrogenation of pinenes under various reaction conditions including heating and/or sonication. Among all, Ru provided some of the best results. After sonication, Ru/C was found highly active and selective for the reduction of a-pinene alone into cis-pinane (99% selectivity at 100% conversion).However, in the absence of sonication the same catalyst was completely inactive. Alumina appeared to be a support with a beneficial chemical effect on the activity of the Ru. Indeed, Ru/Al 2 O 3 was found very active and selective for hydrogenation of both aand b-pinene into cis-pinane (99e100% selectivity at 100% conversion) under mild reaction conditions (room temperature, 400 Psi H 2 ). The selectivity toward cis-pinane decreased in the following order: Ru > Rh > Pt > Pd. An extremely low leaching rate of Ru and other metals determined by inductively coupled plasma mass spectrometry confirmed the heterogeneous nature of this catalytic solvent-free hydrogenation. Ru/C was successfully recycled seven times with no decline in activity and selectivity, whereas Ru/Al 2 O 3 could be used only once to convert pinenes to cis-pinane. Solubilization prediction tests of some natural products have revealed that pinane compares very well with n-hexane and may be an alternative to this fossil-based solvent. When compared experimentally with n-hexane, cis-pinane solubilized 42, two, and three times more of b-carotene, vanillin, and rosmarinic acid, respectively.

As ferulic acid was reported to be involved in novel potential mechanisms associated with Alzheimer’s disease (AD) therapy, five closely related phenethyl esters and amide of this natural product were synthesized and screened for their free radicals scavenging activity. Ferulic acid and its analogue′s absorption, distribution, metabolism, and excretion (ADME) properties were predicted. All compounds obey Lipinski′s rules. Moreover, all evaluated compounds seem to present a high oral bioavailability and blood–brain barrier (BBB) permeation which is crucial for Alzheimer′s disease drug candidates. Molecular docking of analogues 4 and 8 with acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) showed interactions with the residues of the catalytic triad of AChE and BChE. In addition to their interactions with the anionic subsite, hydroferulic acid phenethyl ester 4 and homovanillic acid phenethyl ester 8 may have potential as inhibitors of AChE and BChE, respectively.