New Polyketide and Butenolide Derivatives from the Mangrove Fungus Aspergillus spelaeus SCSIO 41433

Two new racemic mixtures, including a polyketide, (±)-penilactone F (<b>1</b>), and a butenolide, (±) phenylbutyrolactone IIa (<b>2</b>), were isolated from the mangrove sediment-derived strain <i>Aspergillus spelaeus</i> SCSIO 41433. Additionally, 20 known compounds were isolated, including four penicillin-like compounds (<b>11</b>-<b>14</b>), three alkaloids (<b>15</b>-<b>17</b>), one sesquiterpene (<b>18</b>), and four phenolic acids (<b>19</b>-<b>22</b>). Their structures were elucidated through NMR spectroscopy, HRESIMS, X-ray diffraction, and ECD calculations. In the PDE4 inhibitory activity and anticancer cell activity assays, compounds <b>2</b>, <b>3</b>, <b>5</b>, <b>8</b>, <b>9</b>, <b>11</b>-<b>14</b>, and <b>16</b> exhibited weak PDE4 inhibitory activity at a concentration of 10 µM, Compound <b>11</b> demonstrated potent inhibitory effects against six cancer cell lines (MDA-MB-231, MDA-MB-435, HCT116, SNB-19, PC3, and A549), with IC₅₀ values ranging from 3.4 to 23.7 µM.