Garlicinals A-D: Bioactive Organosulfur α,β-Unsaturated Aldehydes from Garlic (Allium sativum L.) Hydrolate

Four sulfur-derived compounds, garlicinals A-D (1-4), were isolated from the garlic (Allium sativum) bulb hydrolate. The structural elucidation of 1-4 was achieved with the help of HRMS and 1D and 2D NMR. All of these compounds are characterized by an α,β-unsaturated aldehyde in their structure. Noteworthy, this structural motif is unique in garlic-derived compounds, which would convert them into a new family of garlic-derived organosulfur compounds. A synthetic path to these compounds is proposed. Garlicinals A-C showed potent fungicidal activity against plant pathogens (Aspergillus niger and Botrytis cinerea). Furthermore, 1-4 were active against the nematode Meloidogyne javanica.