Madangones A and B, two new neolignans from Beilschmiedia madang Blume and their bioactivities

Two new neolignans, madangones A (1) and B (2), together with (+)-kunstlerone (3), vanillin, vanillic acid, betulin, β-sitosterol and β-sitostenone, were isolated from the stem bark of Beilschmiedia madang (Lauraceae). The structures of the compounds were determined by spectroscopic means. The compounds were tested for antioxidant, acetylcholinesterase inhibitory and anti-inflammatory activities. Compound (3) displayed the strongest DPPH radical-scavenging activity with an IC50 value of 68.7 M. Compound (2) exhibited the highest level of activity on the COX-2 model and acetylcholinesterase inhibition assay, with IC50 values of 27.4 and 70.3 µM, respectively

Antioxidant activity of Piper caninum and Cyclooxygenase-2 inhibition by methoxylated flavones.

Background: This study investigated on antioxidant activity of Piper caninum and cyclooxygenase-2 inhibition by methoxylated flavones.Materials and methods: The present study was carried out to quantify the total phenolic content and free radical scavenging activities of the crude extracts by Folin-Ciocalteu and 1,1-diphenyl-2-picrylhydrazyl free radical scavenging assay respectively.Results: Methanolic extracts of Piper caninum exhibited the highest total phenolic content and free radical scavenging activities. All the pure compounds possessed significant cyclooxygenase-2 inhibition at physiological concentrations.Conclusion: Based on in vitro and molecular docking, we therefore suggest that Piper caninum methoxylated flavones are potent inhibitors of cyclooxygenase-2 at physiological concentrationsKey words: Piper caninum; antioxidant; cyclooxygenase-2.List of abbreviations: COX-2, cyclooxygenase-2; DPPH, 2,2-diphenyl- 1-picrylhydrazyl; PGE2, prostaglandin E2

A new xanthone and a new benzophenone from the roots of Garcinia hombroniana

In this study, the roots of Garcinia hombroniana were chemically investigated, in which novel derivatives of xanthone and benzophenone, known as garcihomxanthone (1) and garcihombrianone (2), respectively, together with garceduxanthone (3), cheffouxanthone (4), norathyriol (5), and 2,3′,4,5′-tetrahydroxy-6-methoxybenzophenone (6) were isolated.. The structures of these compounds were elucidated by extensive spectroscopic techniques and evaluated based on references with previous literature data