Synthesis and penicillin‐binding protein inhibitory assessment of dipeptidic 4‐phenyl‐β‐lactams from α‐amino acid‐derived imines

Monocyclic beta-lactams revive the research field on antibiotics, which are threatened by the emergence of resistant bacteria. A six-step synthetic route was developed, providing easy access to new 3-amino-1-carboxymethyl-4-phenyl-beta-lactams, of which the penicillin-binding protein (PBP) inhibitory potency was demonstrated biochemically

Expedient synthesis of lupulones and their derivatization to 2,8-7H-dihydrochromen-7-ones

A convenient and improved method for the synthesis of beta acids or lupulones, which are known to possess e. g. anti-cancer, anti-inflammatory, anti-oxidative and antimicrobial activity, has been developed successfully. Further derivatization of these complex structures to the corresponding dihydrochromen-7-ones, including the natural product machuone, was realized to simplify their analysis and to confirm their molecular structure. In addition to practical and safe laboratory procedures, the advantages associated with this new approach involve the use of water as a solvent and the direct crystallization of lupunones from acetonitrile, rendering our strategy more efficient and benign as compared to available methods

Chemoenzymatic approach toward the synthesis of 3-O-(α/β)-glucosylated 3-hydroxy-β-lactams

Glycosylation significantly alters the biological and physicochemical properties of small molecules. beta-Lactam alcohols comprise eligible substrates for such a transformation based on their distinct relevance in the chemical and medicinal community. In this framework, the unprecedented enzymatic glycosylation of the rigid and highly strained four-membered beta-lactam azaheterocycle was studied. For this purpose, cis-3-hydroxy-beta-lactams were efficiently prepared in three steps by means of a classical organic synthesis approach, while a biocatalytic step was implemented for the selective formation of the corresponding 3-O-alpha- and -beta-glucosides, hence overcoming the complexities typically encountered in synthetic glycochemistry and contributing to the increasing demand for sustainable processes in the framework of green chemistry. Two carbohydrate-active enzymes were selected based on their broad acceptor specificity and subsequently applied for the alpha- or beta-selective formation of beta-lactam-sugar adducts, using sucrose as a glucosyl donor

Chemoenzymatic approach toward the synthesis of 3‑O‑(alfa/beta)-glucosylated 3‑hydroxy-beta-lactams

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