Find in Library

Chromatographic fractionation of the EtOH extracts of the marine-derived fungus <i>Aspergillus</i> <i>versicolor</i> A18 has led to the isolation of 11 homo/hetero-dimers of aromatic bisabolane sesquiterpenoids including eight diphenyl ether-coupled aromatic bisabolanes (<b>1a</b>/<b>1b</b> and <b>5</b>–<b>10</b>) and three homodimers (<b>2</b>–<b>4</b>), together with their monomers including three aromatic bisabolanes (<b>11</b>–<b>13</b>) and two diphenyl ethers (<b>14</b> and <b>15</b>). Their structures and absolute configurations were elucidated by extensive spectroscopic analysis including HRESIMS, 1D/2D NMR, calculated ECD, and the optical rotatory data. Among the four new compounds, (+/−)-asperbisabol A (<b>1a</b>/<b>1b</b>), asperbisabol B (<b>2</b>), and asperbisabol C (<b>3</b>), the enantiomers <b>1a</b> and <b>1b</b> represent an unprecedented skeleton of diphenyl ether-coupled aromatic bisabolane sesquiterpenoids with a spiroketal core moiety. The neuroprotective effects of selected compounds against sodium nitroprusside (SNP)-induced injury were evaluated in PC12 cells by the MTT assay. Five compounds (<b>1a</b>, <b>6</b>, and <b>8</b>–<b>10</b>) showed remarkable neuroprotective activities at 10 μM, being more active than the positive control edaravone.