Acaulins A and B, Trimeric Macrodiolides from <i>Acaulium</i> sp. H‑JQSF

Acaulin A (<b>1</b>) and its macrolactone ring-opened congener acaulin B (<b>2</b>) were characterized from the culture of <i>Acaulium</i> sp. H-JQSF (an isopod-associated fungus) as architecturally undescribed trimeric macrodiolides, with the former being antiosteoporotic at 0.4 μM in the prednisolone-induced osteoporotic zebrafish. Identification of acaudiolic acid (<b>3</b>) as the monomeric macrodiolide precursor facilitated the proposal of the acaulin biosynthetic pathway

Acaulide, an Osteogenic Macrodiolide from <i>Acaulium</i> sp. H‑JQSF, an Isopod-Associated Fungus

Acaulide (<b>1</b>), a macrodiolide with an unprecedented framework, was characterized along with its shunt productsacaulones A (<b>2</b>) and B (<b>3</b>)from the culture of <i>Acaulium</i> sp. H-JQSF associated with the isopod <i>Armadillidium vulgare</i>. The spiro-linked 14-, 14-, and 6-membered cycles of <b>1</b> arise likely from iterative intermolecular Michael addition reactions. Biological evaluation in the prednisolone-induced osteoporotic zebrafish demonstrated that <b>1</b> is antiosteoporotic at 0.4 and 2.0 μM

Citrofulvicin, an Antiosteoporotic Polyketide from <i>Penicillium velutinum</i>

Citrofulvicin (<b>1</b>), along with its early shunt product fulvionol (<b>2</b>), was characterized as a skeletally unprecedented antiosteoporotic agent from a human sputum-derived fungus <i>Penicillium velutinum.</i> The unique citrofulvicin framework is likely formed by a nonenzymatic intermolecular Diels–Alder cycloaddition between heptaketide-based intermediates. Citrofulvicin and fulvionol were demonstrated to be osteogenic at 0.1 μM in the prednisolone-induced osteoporotic zebrafish