The Antiphytopathogenic\nMetabolites and the Synergy\nof Endophytes <i>Paraphaeosphaeria</i> sp., Nigrospora oryzae from the Same Ginkgo\nbiloba Host

Two\nendophytes from the same Ginkgo biloba host were isolated and cultured separately. Three new eremophilane\nsesquiterpenoids (<b>1–3</b>), three new furan derivates\n(<b>6</b>, <b>8</b>–<b>9</b>), one new polyketide\n(<b>10</b>), and four known compounds (<b>4</b>, <b>5</b>, <b>7</b>, <b>11</b>) from <i>Paraphaeosphaeria</i> sp. and two new 10-membered macrolides (<b>12</b>–<b>13</b>), a new liner polyketide (<b>14</b>), a new benzofuran\n(<b>15</b>), and six known compounds (<b>16</b>–<b>21</b>) from Nigrospora oryzae were\nisolated. The structures of the isolated compounds were determined\nby spectroscopic methods, NMR calculations, and ECD calculations.\nThe compounds <b>3</b>–<b>7</b>, <b>9</b>–<b>10</b>, <b>12</b>, and <b>14</b>–<b>17</b> showed significant antiphytopathogenic effects against\nmycotoxigenic <i>Alternaria</i> sp. comparable to the activity\nof nystatin (positive control). Compounds <b>2</b>, <b>6</b>, <b>8</b>, <b>9</b>, and <b>18</b> indicated inhibitions\nagainst phytopathogen Fusarium asiaticum with MICs < 10 μg/mL. In addition, the compounds with weak\nantifungal activities from two endophytes were mixed to test their\nantifungal activity. The results showed that the metabolites from\ntwo endophytes had synergistic antifungal effects, and the beneficial\ninteractions between natural products can induce more antifungal effects\nagainst plant pathogens than that of single compounds.