Thirteen pyrrolidine-based iminosugar derivatives have been synthesized and evaluated for inhibition of α-glucosidase from rat intestine. The compounds studied were the non-hydroxy, mono-hydroxy and dihydroxypyrrolidines. All the compounds were N-benzylated apart from one. Four of the compounds had a carbonyl group in the 2,5-position of the pyrrolidine ring. The most promising iminosugar was the trans-3,4-dihydroxypyrrolidine 5 giving an IC50 of 2.97±0.046 and a KI of 1.18 mM. Kinetic studies showed that the inhibition was of the mixed type, but predominantly competitive for all the compounds tested. Toxicological assay results showed that the compounds have low toxicity. Docking studies showed that all the compounds occupy the same region as the DNJ inhibitor on the enzyme binding site with the most active compounds establishing similar interactions with key residues. Our studies suggest that a rotation of ∼90° of some compounds inside the binding pocket is responsible for the complete loss of inhibitory activity. Despite the fact that activity was found only in the mM range, these compounds have served as simple molecular tools for probing the structural features of the enzyme, so that inhibition can be improved in further studies.

Alerts regarding marine contamination by microplastics motivated this study, conducted in Santa Catarina Island, South Brazil. During 12 sampling events, spatial and temporal distribution of plastic resin pellets, collected at two locations of Campeche beach, was analyzed, and polymer composition was identified. Plastic pellets were found in every sampling day, with a mean average of 1.16 pellets/ m 2 . Their abundance was influenced by two factors: Sampling location and Sampling day nested in each Season. There was a variable abundance along the monitoring period, with an increase of pellets in autumn. A significantly higher amount of pellets was found in one sampling place. The composition of the sampled pellets was heterogeneous, with a prevalence of low density polyethylene polymers. It is clear that a series of proceedings regarding production, stocking, transport and transformation of plastic pellets, must be considered, to avoid pellets loss of into the environment.