Erinacenones A–L: Twelve New Isoindolinone Alkaloids from the Edible and Medicinal Mushroom Hericium erinaceus

A total of twelve previously unreported isoindolin-1-one compounds, erinacenones A-L (<b>1</b>-<b>12</b>), were isolated from liquid cultures of the medicinal fungus <i>Hericium erinaceus</i>. Their structures were elucidated based on spectroscopic data analysis. The absolute configuration of <b>12</b> was determined by comparing its optical rotations with values reported in the literature. The most distinctive feature of these compounds is that their nitrogen atoms are connected to different parts of the special structure moieties. Among them, compounds <b>3</b> and <b>4</b>, as well as <b>10</b> and <b>11</b>, are two pairs of isomers differing only by a small change in the position of one double bond. Compounds <b>4</b> and <b>5</b> were found to show cytotoxic activities, with IC₅₀ values of 24.7 and 18.4 μM, respectively, against MCF-7 cell lines.