3-Hydroxy-7,8,9,10-tetrahydro-6H-benzo[c]chromen-6-one and 3-hydroxy-6H-benzo[c]chromen-6-one act as on-off selective fluorescent sensors for Iron (III) under in vitro and ex vivo conditions

The Synthesis of Urolithins and their Derivatives and the Modes of Antitumor Action

Urolithins are microbial metabolites derived from berries and pomegranate fruits, which display anti-inflammatory, anti-oxidative, and anti-aging activities. There are eight natural urolithins (urolithin A-E, M5, M6 and M7), which have been isolated by now. Structurally, urolithins are phenolic compounds and belong to 6H-dibenzo [b,d] pyran-6-one. They have drawn considerable attention because of their vast range of biological activities and health benefits. Recent studies also suggest that they possess anti-SARS-CoV-2 and anticancer effects. In this article, the recent advances in the synthesis of urolithins and their derivatives from 2015 to 2021 are reviewed. To improve or overcome the solubility and metabolism stability issues, the modifications of urolithins are mainly centered on the hydroxy group and lactone group, and some compounds have been found to display promising results and the potential for further study. The possible modes of antitumor action of urolithin are also discussed. Several signaling pathways, including PI3K-Akt, Wnt/β-catenin pathways, and multiple receptors (aryl hydrocarbon receptor, estrogen and androgen receptors) and enzymes (tyrosinase and lactate dehydrogenase) are involved in the antitumor activity of urolithins.

The investigation of fluorescence and metal interaction properties of racemic 7,8,9,10-tetrahydro-3-hydroxy-4-(1-hydroxyethyl)benzo[c]chromen-6-one

The design or investigation of fluorescence probes continues to receive attention with respect to the diverse applications of spectrofluorometry. Depending on the highly sensitive character, fluorescence spectroscopy-based methodologies have been widely used in recent years in different sciences, including analytical, environmental, and medicinal chemistry areas. In our previous works, we have shown the iron (III) selective on-off sensor properties of benzo[c]chromen-6-one derivatives. In this study, we have extrapolated this research to 4-substituted analogues and investigated both fluorescent and metal interaction properties. Following the synthesis and structure identification studies, (±)-7,8,9,10-tetrahydro-3-hydroxy-4-(1-hydroxyethyl)benzo[c]chromen-6-one was found as a fluorescent molecule displaying fluorescence enhancement in the presence of metals. This feature has been found quite different in comparison to the previous urolithins investigated. This finding suggested the substituent dependent effects and variations on the fluorescent properties of benzo[c]chromen-6-one system.