Two new asteltoxins produced by solid-state fermentation of <i>Pochonia suchlasporia</i> TAMA 87 and their effects on cell division in sea urchin embryos

New asteltoxins U (<b>1</b>) and V (<b>2</b>) were obtained from the solid-state fermentation of <i>Pochonia suchlasporia</i> TAMA 87. The spectroscopic characterization of <b>1</b> and <b>2</b> revealed that their chemical structures are similar to that of asteltoxin H, except for the modification of the α-pyrone moiety. Specifically, the methyl group on the γ-position of the α-pyrone moiety in asteltoxin H is replaced with a hydroxymethyl group in <b>1</b> and <b>2</b>. In addition, <b>1</b> and <b>2</b> are a pair of isomers that differ in the geometry of the double bond between C-11 and C-12 in the conjugated triene moiety and that contain an all-<i>trans</i> (9<i>E</i>, 11<i>E</i>, 13<i>E</i>) moiety and a 9<i>E</i>, 11<i>Z</i>, 13<i>E</i> conjugated triene moiety, respectively. Compound <b>1</b> showed inhibitory activity toward the first cleavage of sea urchin embryos with a minimum inhibition concentration value of 3.1 µg/mL, whereas compound <b>2</b> did not show inhibitory activity up to a concentration of 25 µg/mL.