D. Silvera

Abstract This article presents the design, synthesis and characterization of a series of new acetylenic bis-chalcones (5a-5c) and chalcone functionalized 1,2,3-triazole allied bis-organosilanes (6a-6c) using aldol condensation followed by the Cu(I) catalyzed click strategy. The absorption studies of the designed compounds 5a and 6a were examined towards various metal ions that exhibit their high selectivity and sensitivity towards the recognition of Sn2+ and Hg2+ ions. The sensors show reversible nature upon the addition of disodium salt of ethylenediaminetetraacetic acid. Furthermore, the obtained detection limit with sensors 5a and 6a by plotting calibration curve was 0.34 µM and 0.64 µM for Sn2+ ion and 0.31 µM and 0.15 µM for Hg2+ ion respectively. The association constant value calculated for chemosensors 5a and 6a using the Benesi and Hildebrand plot method was 0.69 × 105 M−1 and 0.18 × 105 M−1 towards Sn2+ ion and 0.67 × 106 M−1 and 0.54 × 106 M−1 towards Hg2+ ion respectively. Moreover, the synthesized compounds 5a and 6a were investigated for their biological application by evaluating their cytotoxicity and antioxidant activity.

Irregular sea urchins such as the spatangoid Spatangus purpureus are important bioturbators that contribute to natural biogenic disturbance and the functioning of biogeochemical cycles in soft sediments. In the coastal waters of the Balearic Islands S. purpureus occurs in soft red algal beds, and can reach high densities. The diet of S. purpureus is unknown and it is particularly difficult to analyze the stomach contents of this group; therefore, we analyzed the fatty acid (FA) composition of the gonads and potential food resources in order to assess the trophic relationships of this species. The FA profiles of the gonads of S. purpureus agree well with the FA composition of the potential trophic resources (algae and sediment) and reveals changes between localities with different available resources. Three polyunsaturated FAs mainly contributes in the composition in the S. purpureus gonads: eicosapentaenoic acid (C20:5n-3) and arachidonic acid (C20:4n-6), both abundant in the macroa...