Accessing HIV-1 Protease Inhibitors through Visible-Light-Mediated Sequential Photocatalytic Decarboxylative Radical Conjugate Addition-Elimination-Oxa-Michael Reactions

A photocatalytic decarboxylative radical conjugate addition-elimination-oxa-Michael reaction of hydroxyalkylated carboxylic acids with cyclopentenones is developed to construct diverse cyclopentanonyl-fused functionalized 5-7 membered cyclic ethers. The stereoselective synthetic strategy is amenable to substructural variation, establishing a direct total synthetic route to two diastereomers of C3-amino cyclopentyltetrahydrofuranyl-derived potent HIV-1 protease inhibitors with low nanomolar IC₅₀ values.

Litsea cubeba fruit essential oil and its major constituent citral as volatile agents in an antimicrobial packaging material

Food packaging films were coated with polyvinyl acetate (PVA) containing different concentrations of citral or Litsea (L.) cubeba essential oil (EO). Antimicrobial contact trials in style of ISO22916 were performed. Citral coatings achieved bactericidal effects against Escherichia coli (2.1 log) and Staphylococcus aureus (4.3 log) at concentrations of 20%_DM. L. cubeba inactivated more than 4 log cycles of both bacteria at a concentration of 20%_DM. To determine the antimicrobial activity across the gas phase, a unique method for volatile agents was developed, adapting ISO22196. GC/MS measurements were performed to supplement microbiological tests in a model packaging system with a defined 220 ml headspace (HS). HS-equilibrium concentrations of 1.8 μg/ml_Air were found for 20%_{DM '}citral-coatings, resulting in antimicrobial effects of 3.8 log against of E. coli. Saccharomyces cerevisiae (4.74 log) and Aspergillus niger (4.29 log) were more effectively inactivated by 3%_DM and 5%_DM coatings. In an application trial with strawberries, simulating a headspace packaging, growth inhibitory effects on the yeast and mold microbiota were found for the 20%_DM coatings.