Daldipyrenones A–C: Caged [6,6,6,6,6] Polyketides Derived from an Endolichenic Fungus Daldinia pyrenaica 047188

Abstract

polyketides featuring a spiro-azaphilone unit, were discovered from an endolichenic fungus, Daldinia pyrenaica 047188. The structures of 1−3 were determined by using spectroscopic analysis and chemical derivatization. Daldipyrenones are likely derived by combining a chromane biosynthesis intermediate, 1-(2,6-dihydroxyphenyl)but-2-en-2-one, and a spiro-azaphilone, pestafolide A, via radical coupling or Michael addition to form a bicyclo[2.2.2]octane ring. Genome sequencing of the strain revealed two separate biosynthetic gene clusters responsible for forming two biosynthetic intermediates, suggesting a proposed biosynthetic pathway. Daldipyrenone A (1) exhibited significant antimelanogenic activity with lower EC 50 's than positive controls and moderate adiponectin-secretion promoting activity.

Endolichenic Fungi: A Promising Medicinal Microbial Resource to Discover Bioactive Natural Molecules—An Update

“…Among them, ulosporins A-G (17-23b) were reported as new compounds for the first time. The other six benzoquinone compounds, 2-acetonyl-3-methyl-5-hydroxy-7-methoxynaphthazarin (24), 6-deoxy-3,4anhydrofusarubin (25), ascomycone A (26), ascomycone B (27), and 6-deoxybostrycoidin (28) were revealed as known compounds. A bioactivity assay test showed that ulosporin G (23) significantly inhibited the growth of the human cancer cell lines A549, MCF-7, and KB tumor cells, with IC 50 values of 1.3, 1.3, and 3.0 µM, respectively.…”

“…8331C [22], and the new compounds biatriosporins G-L (2-7) were reported for the first time in nature. The other anthraquinones were identified as 6-O-demethyl-5-deoxyfusaru- Moreover, thirteen benzoquinone derivatives (17)(18)(19)(20)(21)(22)(23)(24)(25)(26)(27)(28) were isolated from the lichen endophytic fungus Ulospora bilgramii 8344B in 2020 [24]. Among them, ulosporins A-G (17-23b) were reported as new compounds for the first time.…”

“…Moreover, thirteen benzoquinone derivatives (17)(18)(19)(20)(21)(22)(23)(24)(25)(26)(27)(28) were isolated from the lichen endophytic fungus Ulospora bilgramii 8344B in 2020 [24]. Among them, ulosporins A-G (17-23b) were reported as new compounds for the first time.…”

Cytotoxic Peptaibols from Trichoderma guizhouense, a Fungus Isolated from an Urban Soil Sample

“…Most research groups that seek to discover novel bioactive molecules mainly collect samples from undisclosed or unique sources that cannot be easily accessed, such as the Arctic and deep sea. − However, in crowded areas, various factors such as physical forces from people walking on soil, changes in pH by pollutants, and the presence of other harmful organisms can act as elicitors on soil microorganisms, leading to the expression of silent genes and the biosynthesis of novel molecules. − The Natural Products Drug Discovery research group (NPDD) at Duksung Women’s University has isolated fungal strains from soil samples obtained from not only urban areas but also unusual environments in South Korea. Inspired by the University of Oklahoma Citizen Science Soil Collection Program, − we have recruited volunteers (students) to collect soil samples from residential areas and tourist attractions during travel.…”

Hot off the Press

“…The fungus Daldinia pyrenaica 047188, obtained from the lichen Myelochroa aurulenta , produces daldipyrenone A 15 that has a novel pentacyclic ring system. 14 The authors propose that daldipyrenone A 15 is formed from two polyketide precursors. Hyperelatolide A 16 , from Hypericum elatoides , has an unusual carbon skeleton that was confirmed by X-ray analysis.…”