Tavarua Deoxyriboside A and Jasplakinolide as Potential Neuroprotective Agents: Effects on Cellular Models of Oxidative Stress and Neuroinflammation

The oceans harbor a great reservoir of molecules with unknown bioactivities, which could be useful for the treatment of illnesses that nowadays have no cure, such as neurodegenerative diseases. In this work, we evaluated the neuroprotective potential of the marine Fijian compounds tavarua deoxyriboside A and jasplakinolide against oxidative stress and neuroinflammation, crucial mechanisms in neurodegeneration. Both metabolites protected SH-SY5Y human neuroblastoma cells from H₂O₂ damage, improving mitochondrial function and activating the antioxidant systems of cells. These effects were mediated by their ability of inducing Nrf2 translocation. In BV2 microglial cells activated with lipopolysaccharide, Fijian metabolites also displayed promising results, decreasing the release of proinflammatory mediators (ROS, NO, cytokines) through the reduction of gp91 and NFkB-p65 expression. Finally, we performed a coculture among both cell lines, in which treatment with compounds protected SH-SY5Y cells from activated microglia, corroborating their neuroprotective effects. These results suggest that tavarua deoxyriboside A and jasplakinolide could be used as candidate molecules for further studies against neurodegeneration.

The Piancatelli rearrangement of non-symmetrical furan-2,5-dicarbinols for the synthesis of highly functionalized cyclopentenones

Piancatelli rearrangement on substituted non-symmetrical furan-2,5-dicarbinols has been developed using an effective combination of microwave activation and Lewis acid catalyst.

Spatial Distribution of Collections Yielding Marine Natural Products

The societal benefits of coral reef ecosystems include shoreline protection, habitat provision for reef fish, tourism, and recreation. Rarely considered in valuation of reefs is the considerable contribution of marine natural products (MNPs) to both human health and the economy. To better understand the relation of MNP discovery with the characteristics and condition of coral reef ecosystems, we initiated a study to track the collection location and taxonomic identity of organisms that have provided pharmacological products. We reviewed collection information and associated data from 298 pharmacological products originating from marine biota during the past 47 years. The products were developed from 232 different marine species representing 15 phyla, and the 1296 collections of these specimens occurred across 69 countries and seven continents. Our evaluation of the collection data was hampered by sundry observational and reporting issues, including imprecise location descriptions and omission of collection dates. Nonetheless, the study provides an important synopsis and appraisal of years of study and exploration by the marine natural product community. Understanding and quantifying the benefits of MNP discovery will depend upon improved reporting of collections, including accurate taxonomic identification, collection dates, and locations.

Reactivity of alkynylindole-2-carboxamides in [Pd]-catalysed C–H activation and phase transfer catalysis: formation of pyrrolo-diindolones vs. β-carbolinones

[Pd]-Catalysed reaction of 3-alkynylindole-2-carboxamidesviaC–H activation leads to pyrrolodiindolones; in contrast, under phase-transfer catalysis, the same precursors afford β-carbolinones.

Marine natural products

This review covers the literature published in 2012 for marine natural products, with 1035 citations (673 for the period January to December 2012) referring to compounds isolated from marine microorganisms and phytoplankton, green, brown and red algae, sponges, cnidarians, bryozoans, molluscs, tunicates, echinoderms, mangroves and other intertidal plants and microorganisms. The emphasis is on new compounds (1241 for 2012), together with the relevant biological activities, source organisms and country of origin. Biosynthetic studies, first syntheses, and syntheses that lead to the revision of structures or stereochemistries, have been included.