Acetylated Nucleoside Derivatives from a Shallow-Water Marine Bivalve Codakia orbicularis

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Marine natural occurring 2,5-diketopiperazines : isolation, synthesis and optical properties

Seven 2,5-diketopiperazines (DKPs) were isolated from the Fijian marine sponge Acanthella cavernosa. NMR and circular dichroism (CD) comparison with synthetic L-L DKPs allowed us to determine unambiguously the L-L absolute configuration of the natural DKPs. This work initiated the setting up of an optical properties database of natural DKPs, including specific rotation and CD

Pomare project, first results on marine invertebrates quorum sensing inhibitors

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Quorum sensing inhibitors from Leucetta chagosensis Dendy, 1863

Sponges are a rich source for investigation of bioactive small molecules. They have been mostly investigated for the search of new pharmacological models or therapeutic agents for the treatment of human diseases. Micro-organisms can also represent a virulent pathogen for marine invertebrates such as sponges, which need to protect themselves against these microbes. Sponges' self defence mechanisms involving dialogue molecules thus represent a pertinent research track for potent anti-infective and anti-biofilm activities such as quorum sensing inhibitors (QSIs). The investigation of the QSI crude extract of Leucetta chagosensis Dendy, 1863 led to the isolation of three new alkaloids, isonaamine D, di-isonaamidine A and leucettamine D, along with the known isonaamine A and isonaamidine A. Isonaamidine A and isonaamine D were identified as inhibitors of the three quorum sensing pathways of Vibrio harveyi (CAI-1, AI-2 and harveyi auto inducer), but isonaamidine A displayed the strongest activity on AI-2 biosensor. Both compounds are new examples of natural QSIs of V. harveyi. These results outline the importance of these secondary metabolites for their producing organisms themselves in their natural environment, as well as the potential of the marine resource for aquaculture needs

Agelastatin E, agelastatin F, and benzosceptrin C from the marine sponge Agelas dendromorpha J.

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Glass thickness for windows

The choice of glass thickness for windows has always been one of conventional practice. This digest presents information regarding glass strength and wind pressure characteristics. It is now possible to incorporate this information in an improved procedure for determining appropriate glass thicknesses for windows of different sizes subjected to different wind pressures.Aussi disponible en fran\ue7ais : \uc9paisseur du verre destin\ue9 aux fen\ueatresPeer reviewed: NoNRC publication: Ye