Pullenvalenes E–H: Triterpenyl-Aminoglycosides\nfrom an Australian Soil-Derived Fungus, <i>Clonostachys</i> sp.

Chemical profiling of soil-derived microbes collected\nunder the\nauspices of the Australian citizen science initiative Soils for Science\ndetected two fungi, <i>Clonostachys</i> sp. S4S-07771A07\nand <i>Coccidiodes</i> sp. S4S-14879B01, capable of producing\npullenvalenes, a rare class of triterpene glycoside. Cultivation profiling\nfollowed by scaled up cultivation and fractionation of the former\nyielded the known pullenvalenes A–D (<b>1</b>–<b>4</b>) and the new analogues E–H (<b>5</b>–<b>8</b>), with structures secured by detailed spectroscopic analysis\nand biogenetic considerations. This study reveals that the pullenvalenes <b>1</b>–<b>8</b> are produced by several genera of\nfungi (<i>Clonostachys</i>, <i>Coccidiodes</i> and <i>Talaromyces</i>) recovered from different geographic\nlocations and substrates. We also draw attention to structural and\nbiosynthetic similarities with the known Red Sea sponge metabolites\nneviotines A–D (<b>9</b>–<b>12</b>) and\nabudinols A–B (<b>13</b>–<b>14</b>), prompting\nspeculation that the latter may be products of sponge-associated fungi.