p-Terphenyls From Aspergillus sp. GZWMJZ-055: Identification, Derivation, Antioxidant and α-Glycosidase Inhibitory Activities

Abstract

One new (<b>1</b>) and fifteen known (<b>2</b>-<b>16</b>) <i>p</i>-terphenyls were isolated from a solid culture of the endophytic fungus <i>Aspergillus</i> sp. GZWMJZ-055 by adding the leaves of its host <i>Eucommia ulmoides</i>. Furthermore, nine <i>p</i>-terphenyls (<b>17</b>-<b>25</b>) were synthesized from the main compounds (<b>5</b>-<b>7</b>), among which derivatives <b>18</b>, <b>19</b>, <b>21</b>, <b>22</b>, and <b>25</b> are new <i>p</i>-terphenyls. Compounds <b>15</b> and <b>16</b> were also, respectively, synthesized from compounds <b>6</b> and <b>7</b> by oxidative cyclization of air in the presence of silica gel. These <i>p</i>-terphenyls especially those with 4,2',4″-trihydroxy (<b>4</b>-<b>7</b>, <b>20</b>, <b>21</b>) or 4, 4″-dihydroxy-1,2,1',2'-furan (<b>15</b>, <b>16</b>) substituted nucleus, exhibited significant antioxidant and α-glucosidase inhibitory activities and lower cytotoxicity to caco-2 cells. The results indicated their potential use as lead compounds or dietary supplements for treating or preventing the diabetes.