Levomenthol

To address the ecological pollution caused by synthetic antimicrobial agents in conventional food packaging films, we have successfully developed a fully bio-based and sustainable food packaging film that exhibits exceptional antibacterial and antioxidant properties. In this study, we designed and synthesized two novel natural alcohol esters of amino acid (NAEAAs)-L-Trp-Men and L-Trp-Bor-through esterification reactions involving L-tryptophan (L-Trp) and L-Menthol or Borneol, respectively. A multifunctional composite film system was constructed using natural corn starch (CS) and sodium carboxymethyl cellulose (CMC) as the matrix materials, with NAEAAs serving as the antimicrobial active components and curcumin (Cur) as the antioxidant. Experimental results demonstrated that the CS/CMC/Men2/Cur2 composite film, containing 2 wt% additives, exhibited nearly complete (≈100 %) broad-spectrum antibacterial efficiency against both Escherichia coli and Staphylococcus aureus, alongside a DPPH radical scavenging rate of 45.69 ± 1.39 %. Cytotoxicity tests confirmed the excellent biocompatibility of NAEAAs, which hydrolyze into amino acids and natural alcohols, thereby minimizing environmental contamination. These fully natural material-based films present a novel approach for developing green, pollution-free, and renewable bio-based food packaging materials.

Halogen-atom transfer (XAT) is an effective method for generating carbon radicals from alkyl halides. While stannanes and silanes have shown potential, their toxicity and secondary reactivity necessitate the search for better alternatives. Recently, carbon-based α-amino alkyl radicals have emerged as possible substitutes; however, their generation under photochemical conditions requires the use of photocatalysts. In this work, we present a novel XAT method that eliminates the need for photocatalysts by utilizing the direct excitation of a monofluoroacetoxy ligand-containing hypervalent iodine(III) reagent. This approach allows nucleophilic monofluoromethyl radicals to efficiently form carbon radicals from activated alkyl halides. These radicals can subsequently functionalize unactivated alkenes through atom transfer radical addition (ATRA). Our mechanistic studies provide insights into the generation of monofluoromethyl radical and its unique reactivity. This work highlights the untapped potential of simple, single carbon atom-containing radicals for effective alkyl radical generation.