Identification of compounds inhibiting the C‐S lyase activity of a cell extract from a Staphylococcus sp. isolated from human skin

The C‐S lyase activity of bacteria in the human armpit releases highly malodorous, volatile sulfur compounds from nonvolatile precursor molecules. Such compounds significantly contribute to human body odour. Hence, C‐S lyase represents an attractive target for anti‐body‐odour cosmetic products. Here, aiming at a final use in an ethanol‐based deodorant formulation, 267 compounds and compound mixtures were screened for their ability to inhibit the C‐S lyase activity of a Stapyhlococcus sp. crude extract. Staphylococcus sp. Isolate 128, closely related to Staphylococcus hominis, was chosen as the test bacterium, as it showed a reproducibly high specific C‐S lyase activity on three different culturing media. Using a photometric assay and benzylcysteine as substrate, six rather complex, plant‐derived compound mixtures and five well defined chemical compounds or compound mixtures were identified as inhibitors, leading to an inhibition of ≥70% at concentrations of ≤0·5% in the assay. The inhibition data have demonstrated that compounds with two vicinal hydroxyl groups or one hydroxyl and one keto group bound to an aryl residue are characteristic for the inhibition. The substances identified as C‐S lyase inhibitors have the potential to improve the performance of anti‐body‐odour cosmetic products, for example, ethanol‐based deodorants. Significance and Impact of the Study Bacterial C‐S lyase represents one of the key enzymes involved in human body odour formation. The aim of this study was to identify compounds inhibiting the C‐S lyase activity of a Staphylococcus sp. isolate from the human skin. The compounds identified as the best inhibitors are characterized by the following features: two vicinal hydroxyl groups or one hydroxyl and one keto group bound to an aryl residue. They might be used to improve the performance of cosmetic products aiming to prevent the formation of microbially caused human body odour, for example, ethanol‐based deodorants. Significance and Impact of the Study: Bacterial C‐S lyase represents one of the key enzymes involved in human body odour formation. The aim of this study was to identify compounds inhibiting the C‐S lyase activity of a Staphylococcus sp. isolate from the human skin. The compounds identified as the best inhibitors are characterized by the following features: two vicinal hydroxyl groups or one hydroxyl and one keto group bound to an aryl residue. They might be used to improve the performance of cosmetic products aiming t