Transformation mechanism, kinetics and ecotoxicity of kaempferol and quercetin in the gaseous and aqueous phases: A theoretical combined experimental study.

The transformation and risk assessment of flavonoids triggered by free radicals deserve extensive attention. In this work, the degradation mechanisms, kinetics, and ecotoxicity of kaempferol and quercetin mediated by ∙OH, ∙OCH, ∙OOH, and O in gaseous and aqueous environments were investigated using cell experiments and quantum chemical calculations. Three radical scavenging mechanisms, including hydrogen atom transfer (HAT), radical adduct formation (RAF) and single electron transfer (SET) were discussed.

New amides from seeds of Silybum marianum with potential antioxidant and antidiabetic activities.

Two new amide compounds, mariamides A and B (1-2), were obtained together with fourteen known compounds from the seeds of milk thistle (Silybum marianum). Their structures were established on the basis of extensive 1D and 2D NMR analyses, as well as HR-ESI-MS data. Most of the compounds showed significant antioxidant activities than positive control in ABTS and FRAP assays.