Free Radical Mediated Oxidative Degradation of Carotenes and Xanthophylls.

This article reviews the excited-state quenching, pro-vitamin A activity and anticarcinogenicity of carotenes and xanthophylls in relation to their chemical structures. Excited-state quenching improved with the length of the conjugated chain structure. Pro-vitamin A activity was dependent on the presence of at least one beta-ionyl ring structure. The effectiveness of carotenoids as antioxidants depended on their ability to trap peroxyl radicals with production of resonance-stabilized carotenyl radicals. The products identified from oxidations of carotenes and xanthophylls with molecular oxygen and other oxidizing agents are presented. The free radical-mediated mechanisms that have been proposed to account for the different classes of products are reviewed.

Recent advances in chemistry and therapeutic potential of functionalized quinoline motifs - a review.

Quinoline, which consists of benzene fused with N-heterocyclic pyridine, has received considerable attention as a core template in drug design because of its broad spectrum of bioactivity. This review aims to present the recent advances in chemistry, medicinal potential and pharmacological applications of quinoline motifs to unveil their substantial efficacies for future drug development. Essential information in all the current and available literature used was accessed and retrieved using different search engines and databases, including Scopus, ISI Web of Knowledge, Google and PUBMED. Numerous derivatives of the bioactive quinolines have been harnessed via expeditious synthetic approaches, as highlighted herein. This review reveals that quinoline is an indisputable pharmacophore due to its tremendous benefits in medicinal chemistry research and other valuable areas of human endeavour. The recent in vivo and in vitro screening reported by scientists is highlighted herein, which may pave the way for novel drug development. Owing to the array of information available and highlighted herein on the medicinal potential of quinoline and its functionalized derivatives, a new window of opportunity may be opened to medicinal chemists to access more biomolecular quinolines for future drug development.