Beta-Lactamase Database (BLDB) is a comprehensive, manually curated public resource providing up-to-date structural and functional information focused on this superfamily of enzymes with a great impact on antibiotic resistance. All the enzymes reported and characterised in the literature are presented according to the class (A, B, C and D), family and subfamily to which they belong. All three-dimensional structures of β-lactamases present in the Protein Data Bank are also shown. The characterisation of representative mutants and hydrolytic profiles (kinetics) completes the picture and altogether these four elements constitute the essential foundation for a better understanding of the structure-function relationship within this enzymes family. BLDB can be queried using different protein- and nucleotide-based BLAST searches, which represents a key feature of particular importance in the context of the surveillance of the evolution of the antibiotic resistance. BLDB is available online at http://bldb.eu without any registration and supports all modern browsers.
Novel 2,5-meso-pyrrolidines have been straightforwardly synthesized from readily available symmetrical double Michael acceptors. The key step rested on an aza-Michael addition of primary alkylamines to bis-enones. Competitive Rauhut–Currier and aza-Michael reactions have been highlighted in protic solvent. Ultrasound activation associated with solvent-free conditions led to the expected pyrrolidines in quantitative yields and excellent stereoselectivities. The optimized conditions have been extended to the sonochemical synthesis of pyrrolidine Lobelia alkaloids analogues in short sequences.