Production of New Antibacterial 4-Hydroxy-α-Pyrones by a Marine Fungus Aspergillus niger Cultivated in Solid Medium

Abstract

Four 4-hydroxy-α-pyrones including three new ones named nipyrones A–C (1–3) together with one known analogue germicidin C (4) were discovered from a marine sponge-derived fungus Aspergillus niger cultivated in a solid rice culture. Their structures and absolute configurations were elucidated through a combination of spectroscopic data and electronic circular dichroism (ECD) calculations as well as comparison with literature data. Compounds 1–4 were evaluated for their antibacterial activities against five pathogenic bacteria (Staphylococcus aureus, Escherichia coli, Bacillus subtilis, methicillin-resistant Staphylococcus aureus, and Mycobacterium tuberculosis). Compound 3 showed promising activity against S. aureus and B. subtilis, with minimum inhibitory concentration (MIC) values of 8 μg/mL and 16 μg/mL, respectively, and displayed weak antitubercular activities against M. tuberculosis, with MIC value of 64 μg/mL, while compounds 1 and 2 exhibited moderate antibacterial efficacy against four pathogenic bacteria with MIC values of 32–64 μg/mL.

Screening of anti‐ Vibrio activity of marine fungal methanolic fractions to control vibriosis in white shrimp ( Litopenaeus vannamei )

“…Natural products from marine fungi have been considered a significant source for the discovery of novel compounds that possess diverse biological activities, including cytotoxic, antitumor, antiviral, antibacterial, antifungal and anti‐inflammatory activities (Imhoff, 2016). Increasing number of compounds from marine fungi has been reported with inhibiting activities against microbial pathogens including methicillin‐resistant Staphylococcus aureus , Mycobacterium tuberculosis , Escherichia coli , Klebsiella pneumonia and Pseudomonas aeruginosa (Ding et al, 2019; Song et al, 2018; Zhou et al, 2016). However, only few studies contain data about the effects against pathogenic vibrios.…”

Antibiotics Development and the Potentials of Marine-Derived Compounds to Stem the Tide of Multidrug-Resistant Pathogenic Bacteria, Fungi, and Protozoa

“…The rice culture of A. niger from marine sponge (Haliclona sp) tissues produced new 4-hydroxy-αpyrones (nipyrones A-C (1-3)) and a known analogue, germicidin C (4). These compounds, which differ in their functional group substitution and side chain length, exhibited weak to moderate antimicrobial activities with MRSA [107].…”

Natural Polypropionates in 1999–2020: An Overview of Chemical and Biological Diversity

“…Using the incorporations of 13 C-labeled acetate/malonate and deuterated methionine led to The fungi are the main producer of 2-pyrone-containing PPs (Figure 9). Three different species of Aspergillus genus yielded five metabolites, including nipyrones A-C (42-44) [31], versicolone A (45) [32] and neovasinin (46) [19]. The stereochemistry of the chiral centers at the side chain of 42-44 was deduced by the NOE correlations and ECD calculations while the 9R, 11R configuration of 45 was established by comparing the optical rotation between natural isolates and ascosalitoxin isomers.…”