Microsphaerones A and B, Two Novel γ-Pyrone Derivatives from the Sponge-Derived Fungus Microsphaeropsis sp.

Abstract

Two new metabolites, microsphaerones A (1) and B (2), were identified from the EtOAc extract of the culture of an undescribed fungus of the genus Microsphaeropsis, isolated from the Mediterranean sponge Aplysina aerophoba. Compounds 1 and 2 represent the first examples of gamma-pyrone derivatives of the fungal genus Microsphaeropsis. The structures of the compounds were elucidated on the basis of comprehensive spectral analysis ((1)H, (13)C, (1)H-(1)H COSY, HMQC, and HMBC NMR, as well as low- and high-resolution ESI and EIMS experiments). The (S)-2-methylsuccinic acid moiety present in 1 was established by GC-MS analysis of a hydrolysis product.

Oximoaspergillimide, a Fungal Derivative from a Marine Isolate of Aspergillus sp.

“…[33] Although unusual, the linear imide moiety is not unique to oximoaspergillimide (1). It is also found in a small group of recently characterized fungal metabolites, mostly natural tyrosine derivatives, that includes nygerone A, [34] microsphaerone A, [35] and pestalamide B. [36] However, these metabolites do not contain an oxime unit in their structures.…”

Endophytic fungi from Chilean native gymnosperms: antimicrobial activity against human and phytopathogenic fungi

“…This fungus has previously been isolated from the peduncle bark and xylem of Eucalyptus globulus (Lupo et al 2001); lichens (Seephonkai et al 2002); marine sponges including Agelus sp., collected from Sombrero Key East, Florida; Myxila incrustans, from the island of Helgoland, Germany; and Aplysina aerophoba from the Mediterranean Sea. This fungus has been reported to produce several biologically active compounds including cerebrosides (Keusgen et al 1996), unusual fatty acids and their glycerides , microsphaeropsisin, (R)-mellein, (3R, 4S)-hydroxymellein, (3R, 4R)-hydroxymellein, and 4,8-dihydroxy-3,4-dihydro-2H-naphthalen-1-one (Höller et al 1999), microsphaerones A and B (Wang et al 2002), preussomerins (Seephonkai et al 2002), anthraquinones, and betaenone derivatives (Brauers et al 2000). The second fungus with biological activity was the sterile mycelia E-3, with effect against Microsporum canis, M. gypseum, Epidermophyton floccosum, Trichophyton rubrum, and T. mentagrophytes with MICs of 125, 250, 100, 100, and 125 lg/ml, respectively.…”

Eurothiocin A and B, Sulfur-Containing Benzofurans from a Soft Coral-Derived Fungus Eurotium rubrum SH-823

“…Among invertebrate-associated fungi, most studies of secondary metabolites have focused on those derived from sponges [3,10,11,12,13]. By contrast, although soft corals have been shown to host a variety of fungi [14,15,16,17], chemical investigation of these fungi are relatively rare.…”