Depsidone Derivatives and a Cyclopeptide Produced by Marine Fungus Aspergillus unguis under Chemical Induction and by Its Plasma Induced Mutant

Abstract

A new depsidone derivative (1), aspergillusidone G, was isolated from a marine fungus Aspergillus unguis, together with eight known depsidones (2‒9) and a cyclic peptide (10): agonodepside A (2), nornidulin (3), nidulin (4), aspergillusidone F (5), unguinol (6), aspergillusidone C (7), 2-chlorounguinol (8), aspergillusidone A (9), and unguisin A (10). Compounds 1‒4 and 7‒9 were obtained from the plasma induced mutant of this fungus, while 5, 6, and 10 were isolated from the original strain under chemical induction. Their structures were identified using spectroscopic analysis, as well as by comparison with literature data. The HPLC fingerprint analysis indicates that chemical induction and plasma mutagenesis effectively influenced the secondary metabolism, which may be due to their regulation in the key steps in depsidone biosynthesis. In bioassays, compound 9 inhibited acetylcholinesterase (AChE) with IC50 in 56.75 μM. Compounds 1, 5, 7, 8, and 9 showed moderate to strong activity towards different microbes. Compounds 3, 4, and 5 exhibited potent larvicidality against brine shrimp. In docking studies, higher negative CDOCKER interaction energy and richer strong interactions between AChE and 9 explained the greater activity of 9 compared to 1. Chemical induction and plasma mutagenesis can be used as tools to expand the chemodiversity of fungi and obtain useful natural products.

Counting and identification of molds and yeasts in dry salted shrimp commercialized in Rio Branco, Acre, Brazil

“…Fungal species called halophilic tolerate high concentrations of salinity, allowing their maintenance in the product even after the salting process (Silva et al, 2015), as recorded in this study. For example, Zhou et al (2018), Yang et al (2018) and Das et al (2019) described Trichothecium roseum, Aspergillus unguis and Aspergillus terreus, respectively, as halophilic fungi of marine origin, detected in shrimp samples.…”

Peniazaphilones A—I, Produced by Co‐culturing of Mangrove Endophytic Fungi, Penicillium sclerotiorumTHSH‐4 and Penicillium sclerotiorumZJHJJ‐18

“…[ 12‐14 ] Varieties of culture methods can be used to activate gene clusters that are not expressed in microbes and stress them to produce diverse secondary metabolites. [ 15‐17 ] The co‐cultivation of microorganisms is an effective strategy for inducing the production of rare metabolites. [ 18‐20 ] In our previous studies, two kinds of Penicillium sclerotiorum , THSH‐4 and ZJHJJ‐18 can produce rich metabolites including azaphilones.…”

Marine-Derived Compounds with Anti-Alzheimer’s Disease Activities

“…and van der Waals (Trp-84, Tyr-334, Phe-331, Phe-330, etc.) interactions exist between 49 and AChE [ 42 ]. The extracts of a culture broth and mycelia of a marine sponge-associate fungus Talaromyces sp.…”