Cylindromicin from Arctic-Derived Fungus Tolypocladium sp. SCSIO 40433

Tetramic acid-motif natural products from a marine fungus Tolypocladium cylindrosporum FB06 and their anti-Parkinson activities

Tetramic acid-containing natural products are attracting significantly increasing attention from biologists and chemists due to their intriguing structures and biological activities. In the present study, two new tetramic acid alkaloids tolypyridone I (1) and tolypyridone J (2), together with five known ones (3-7), were isolated from cultures of a marine fungus Tolypocladium cylindrosporum FB06 isolate obtained from a marine sediment in Beaufort sea of North Alaska. Their structures were elucidated using 1D, 2D NMR, and HRESIMS. Their configurations were established on the basis of 1H coupling constants, ROESY correlations and DP4 calculations. Compound 2 was isolated as mixtures of rotational isomers with C-3 to C-7 axis between 4-hydroxy-2-pyridone and 1-ethyl-3,5-dimethylcyclohexane, hindering rotation. In our unbiased screening to discover neuroprotective compounds in an in vitro Parkinson's disease (PD) model, SH-SY5Y dopaminergic cells were treated with isolated compounds followed by treatment with 1-methyl-4-phenylpyridinium (MPP+), a parkinsonian neurotoxin. Among tested compounds, F-14329 (7) significantly protected cells from MPP+-induced cytotoxicity. MPP+-mediated cell death is known to be related to the regulation of Bcl-2 family proteins, specifically the down-regulation of anti-apoptotic Bcl-2 and the up-regulation of pro-apoptotic Bax levels. Treatment with 2 mmol/L of MPP+ for 24 h significantly reduced Bcl-2 levels compared to control treated with vehicle. However, treatment with F-14329 (7) attenuated such reduction. This study demonstrates that tetramic acid-motif compounds could be potential lead compounds for treating PD.

Supplementary Information

The online version contains supplementary material available at 10.1007/s42995-023-00198-7.

Liver-cell protective pyridones from the fungi Tolypocladium album dws120

Five previously undescribed pyridone derivatives, tolypyridones I-M, were identified from the solid rice medium fermented by Tolypocladium album dws120, along with two known compounds tolypyridone A (or trichodin A) and pyridoxatin. Their planar structures and partial relative configurations have been determined by careful interpretation of their spectroscopic data. The full assignment of the relative and absolute configurations of tolypyridones I-M was achieved by gauge-independent atomic orbital ¹³C NMR calculation, quantitative nuclear Overhauser effects based interatomic distance calculation, and electronic circular dichroism calculation. In addition, we have fully determined the configuration of tolypyridone A by X-ray diffraction analysis. In bioassay, tolypyridones I was able to restore cell viability and inhibit the release of alanine aminotransferase and aspartate aminotransferase for ethanol-induced LO2 cell, suggesting its potential as a liver protective agent.

Phylogeny and Systematics of the Genus Tolypocladium (Ophiocordycipitaceae, Hypocreales)

The taxonomy and phylogeny of the genus Tolypocladium are herein revised based on the most comprehensive dataset to date. Two species-level phylogenies of Tolypocladium were constructed: a single-gene phylogeny (ITS) of 35 accepted species and a multigene phylogeny (nrSSU, nrLSU, tef-1α, rpb1, and rpb2) of 27 accepted species. Three new species, Tolypocladium pseudoalbum sp. nov., Tolypocladium subparadoxum sp. nov., and Tolypocladium yunnanense sp. nov., are described in the present study. The genetic divergences of four markers (ITS, tef-1α, rpb1 and rpb2) among Tolypocladium species are also reported. The results indicated that species of Tolypocladium were best delimited by rpb1 sequence data, followed by the sequence data for the rpb2, tef-1α, and ITS provided regions. Finally, a key to the 48 accepted species of Tolypocladium worldwide is provided.

Application of Marine Microbial Natural Products in Cosmetics

As the market size of the cosmetics industry increases, the safety and effectiveness of new products face higher requirements. The marine environment selects for species of micro-organisms with metabolic pathways and adaptation mechanisms different from those of terrestrial organisms, resulting in their natural products exhibiting unique structures, high diversity, and significant biological activities. Natural products are usually safe and non-polluting. Therefore, considerable effort has been devoted to searching for cosmetic ingredients that are effective, safe, and natural for marine micro-organisms. However, marine micro-organisms can be difficult, or impossible, to culture because of their special environmental requirements. Metagenomics technology can help to solve this problem. Moreover, using marine species to produce more green and environmentally friendly products through biotransformation has become a new choice for cosmetic manufacturers. In this study, the natural products of marine micro-organisms are reviewed and evaluated with respect to various cosmetic applications.