PTP1B Inhibitory Secondary Metabolites from an Antarctic Fungal Strain Acremonium sp. SF-7394

Recent Advances in Chemistry and Bioactivities of Secondary Metabolites from the Genus Acremonium

Acremonium fungi is one of the greatest and most complex genera in Hyphomycetes, comprising 130 species of marine and terrestrial sources. The past decades have witnessed substantial chemical and biological investigations on the diverse secondary metabolites from the Acremonium species. To date, over 600 compounds with abundant chemical types as well as a wide range of bioactivities have been obtained from this genus, attracting considerable attention from chemists and pharmacologists. This review mainly summarizes the sources, chemical structures, and biological activities of 115 recently reported new compounds from the genus Acremonium from December 2016 to September 2023. They are structurally classified into terpenoids (42%), peptides (29%), polyketides (20%), and others (9%), among which marine sources are predominant (68%). Notably, these compounds were primarily screened with cytotoxic, antibacterial, and anti-inflammatory activities. This paper provides insights into the exploration and utilization of bioactive compounds in this genus, both within the scientific field and pharmaceutical industry.

Macrosphelides from Antarctic fungus Pseudogymnoascus sp. (strain SF-7351) and their neuroprotective effects on BV2 and HT22 cells

Strategies for reducing inflammation in neurodegenerative diseases have attracted increasing attention. Herein, we discovered and evaluated the neuroprotective potential of fungal metabolites isolated from the Antarctic fungus Pseudogymnoascus sp. (strain SF-7351). The chemical investigation of the EtOAc extract of the fungal strain isolate revealed a novel naturally occurring epi-macrosphelide J (1), a novel secondary metabolite macrosphelide N (2), and three known compounds, namely macrosphelide A (3), macrosphelide B (4), and macrosphelide J (5). Their structures were established unambiguously using spectroscopic methods, such as one-dimensional and two-dimensional nuclear magnetic resonance (1D and 2D-NMR) spectroscopy, high-resolution electrospray ionization mass spectrometry (HR-ESI-MS), and gauge-including atomic orbital (GIAO) NMR chemical shift calculations, with the support of the advanced statistical method DP4+. Among the isolated metabolites, the absolute configuration of epi-macrosphelide J (1) was further confirmed using single-crystal X-ray diffraction analysis. The neuroprotective effects of the isolated metabolites were evaluated in lipopolysaccharide (LPS)-induced BV2 and glutamate-stimulated HT22 cells. Only macrosphelide B (4) displayed substantial protective effects in both BV2 and HT22 cells. Molecular mechanisms underlying this activity were investigated using western blotting and molecular docking studies. Macrosphelide B (4) inhibited the inflammatory response by reducing the nuclear translocation of NF-κB (p65) in LPS-induced BV2 cells and induced the Nrf2/HO-1 signaling pathway in both BV2 and HT22 cells. The neuroprotective effect of macrosphelide B (4) is related to the interaction between Keap1 and p65. These results suggest that macrosphelide B (4), present in the fungus Pseudogymnoascus sp. (strain SF-7351), may serve as a candidate for the treatment of neurodegenerative diseases.

Redisposition of acremonium-like fungi in Hypocreales

Acremonium is acknowledged as a highly ubiquitous genus including saprobic, parasitic, or endophytic fungi that inhabit a variety of environments. Species of this genus are extensively exploited in industrial, commercial, pharmaceutical, and biocontrol applications, and proved to be a rich source of novel and bioactive secondary metabolites. Acremonium has been recognised as a taxonomically difficult group of ascomycetes, due to the reduced and high plasticity of morphological characters, wide ecological distribution and substrate range. Recent advances in molecular phylogenies, revealed that Acremonium is highly polyphyletic and members of Acremonium s. lat. belong to at least three distinct orders of Sordariomycetes, of which numerous orders, families and genera with acremonium-like morphs remain undefined. To infer the phylogenetic relationships and establish a natural classification for acremonium-like taxa, systematic analyses were conducted based on a large number of cultures with a global distribution and varied substrates. A total of 633 cultures with acremonium-like morphology, including 261 ex-type cultures from 89 countries and a variety of substrates including soil, plants, fungi, humans, insects, air, and water were examined. An overview phylogenetic tree based on three loci (ITS, LSU, rpb2) was generated to delimit the orders and families. Separate trees based on a combined analysis of four loci (ITS, LSU, rpb2, tef-1α) were used to delimit species at generic and family levels. Combined with the morphological features, host associations and ecological analyses, acremonium-like species evaluated in the present study are currently assigned to 63 genera, and 14 families in Cephalothecales, Glomerellales and Hypocreales, mainly in the families Bionectriaceae, Plectosphaerellaceae and Sarocladiaceae and five new hypocrealean families, namely Chrysonectriaceae, Neoacremoniaceae, Nothoacremoniaceae, Pseudoniessliaceae and Valsonectriaceae. Among them, 17 new genera and 63 new combinations are proposed, with descriptions of 65 new species. Furthermore, one epitype and one neotype are designated to stabilise the taxonomy and use of older names. Results of this study demonstrated that most species of Acremonium s. lat. grouped in genera of Bionectriaceae, including the type A. alternatum. A phylogenetic backbone tree is provided for Bionectriaceae, in which 183 species are recognised and 39 well-supported genera are resolved, including 10 new genera. Additionally, rpb2 and tef-1α are proposed as potential DNA barcodes for the identification of taxa in Bionectriaceae. Taxonomic novelties: New families: Chrysonectriaceae L.W. Hou, L. Cai & Crous, Neoacremoniaceae L.W. Hou, L. Cai & Crous, Nothoacremoniaceae L.W. Hou, L. Cai & Crous, Pseudoniessliaceae L.W. Hou, L. Cai & Crous, Valsonectriaceae L.W. Hou, L. Cai & Crous. New genera: Bionectriaceae: Alloacremonium L.W. Hou, L. Cai & Crous, Gossypinidium L.W. Hou, L. Cai & Crous, Monohydropisphaera L.W. Hou, L. Cai & Crous, Musananaesporium L.W. Hou, L. Cai & Crous, Paragliomastix L.W. Hou, L. Cai & Crous, Proliferophialis L.W. Hou, L. Cai & Crous, Proxiovicillium L.W. Hou, L. Cai & Crous, Ramosiphorum L.W. Hou, L. Cai & Crous, Verruciconidia L.W. Hou, L. Cai & Crous, Waltergamsia L.W. Hou, L. Cai & Crous; Clavicipitaceae: Subuliphorum L.W. Hou, L. Cai & Crous; Neoacremoniaceae: Neoacremonium L.W. Hou, L. Cai & Crous; Nothoacremoniaceae: Nothoacremonium L.W. Hou, L. Cai & Crous; Plectosphaerellaceae: Allomusicillium L.W. Hou, L. Cai & Crous, Parafuscohypha L.W. Hou, L. Cai & Crous; Pseudoniessliaceae: Pseudoniesslia L.W. Hou, L. Cai & Crous; Sarocladiaceae: Polyphialocladium L.W. Hou, L. Cai & Crous. New species: Bionectriaceae: Alloacremonium ferrugineum L.W. Hou, L. Cai & Crous, Al. humicola L.W. Hou, L. Cai & Crous, Acremonium aerium L.W. Hou, L. Cai & Crous, A. brunneisporum L.W. Hou, L. Cai & Crous, A. chlamydosporium L.W. Hou, L. Cai & Crous, A. ellipsoideum L.W. Hou, Rämä, L. Cai & Crous, A. gamsianum L.W. Hou, L. Cai & Crous, A. longiphialidicum L.W. Hou, L. Cai & Crous, A. multiramosum L.W. Hou, Rämä, L. Cai & Crous, A. mycoparasiticum L.W. Hou, L. Cai & Crous, A. stroudii K. Fletcher, F.C. Küpper & P. van West, A. subulatum L.W. Hou, L. Cai & Crous, A. synnematoferum L.W. Hou, Rämä, L. Cai & Crous, Bulbithecium ammophilae L.W. Hou, L. Cai & Crous, B. ellipsoideum L.W. Hou, L. Cai & Crous, B. truncatum L.W. Hou, L. Cai & Crous, Emericellopsis brunneiguttula L.W. Hou, L. Cai & Crous, Gliomastix musae L.W. Hou, L. Cai & Crous, Gossypinidium sporodochiale L.W. Hou, L. Cai & Crous, Hapsidospora stercoraria L.W. Hou, L. Cai & Crous, H. variabilis L.W. Hou, L. Cai & Crous, Mycocitrus odorus L.W. Hou, L. Cai & Crous, Nectriopsis ellipsoidea L.W. Hou, L. Cai & Crous, Paracylindrocarpon aurantiacum L.W. Hou, L. Cai & Crous, Pn. foliicola Lechat & J. Fourn., Paragliomastix rosea L.W. Hou, L. Cai & Crous, Proliferophialis apiculata L.W. Hou, L. Cai & Crous, Protocreopsis finnmarkica L.W. Hou, L. Cai, Rämä & Crous, Proxiovicillium lepidopterorum L.W. Hou, L. Cai & Crous, Ramosiphorum echinoporiae L.W. Hou, L. Cai & Crous, R. polyporicola L.W. Hou, L. Cai & Crous, R. thailandicum L.W. Hou, L. Cai & Crous, Verruciconidia erythroxyli L.W. Hou, L. Cai & Crous, Ve. infuscata L.W. Hou, L. Cai & Crous, Ve. quercina L.W. Hou, L. Cai & Crous, Ve. siccicapita L.W. Hou, L. Cai & Crous, Ve. unguis L.W. Hou, L. Cai & Crous, Waltergamsia alkalina L.W. Hou, L. Cai & Crous, W. catenata L.W. Hou, L. Cai & Crous, W. moroccensis L.W. Hou, L. Cai & Crous, W. obpyriformis L.W. Hou, L. Cai & Crous; Chrysonectriaceae: Chrysonectria crystallifera L.W. Hou, L. Cai & Crous; Nectriaceae: Xenoacremonium allantoideum L.W. Hou, L. Cai & Crous; Neoacremoniaceae: Neoacremonium distortum L.W. Hou, L. Cai & Crous, N. flavum L.W. Hou, L. Cai & Crous; Nothoacremoniaceae: Nothoacremonium subcylindricum L.W. Hou, L. Cai & Crous, No. vesiculophorum L.W. Hou, L. Cai & Crous; Myrotheciomycetaceae: Trichothecium hongkongense L.W. Hou, L. Cai & Crous; Plectosphaerellaceae: Brunneomyces polyphialidus L.W. Hou, L. Cai & Crous, Parafuscohypha proliferata L.W. Hou, L. Cai & Crous; Sarocladiaceae: Chlamydocillium acaciae L.W. Hou, L. Cai & Crous, C. antarcticum L.W. Hou, L. Cai & Crous, C. guttulatum L.W. Hou, L. Cai & Crous, C. lolii L.W. Hou, L. Cai & Crous, C. soli L.W. Hou, L. Cai & Crous, C. terrestre L.W. Hou, L. Cai & Crous, Parasarocladium chondroidum L.W. Hou, L. Cai & Crous,Polyphialocladium fusisporum L.W. Hou, L. Cai & Crous, Sarocladium agarici L.W. Hou, L. Cai & Crous, S. citri L.W. Hou, L. Cai & Crous, S. ferrugineum L.W. Hou, L. Cai & Crous, S. fuscum L.W. Hou, L. Cai & Crous,S. theobromae L.W. Hou, L. Cai & Crous; Valsonectriaceae: Valsonectria crystalligena L.W. Hou, L. Cai & Crous, V. hilaris L.W. Hou, L. Cai & Crous. New combinations: Bionectriaceae: Acremonium purpurascens (Sukapure & Thirum.) L.W. Hou, L. Cai & Crous, Bulbithecium arxii (Malloch) L.W. Hou, L. Cai & Crous, Bu. borodinense (Tad. Ito et al.) L.W. Hou, L. Cai & Crous, Bu. pinkertoniae (W. Gams) L.W. Hou, L. Cai & Crous, Bu. spinosum (Negroni) L.W. Hou, L. Cai & Crous, Emericellopsis exuviara (Sigler et al.) L.W. Hou, L. Cai & Crous, E. fimetaria (Pers.) L.W. Hou, L. Cai & Crous, E. fuci (Summerb. et al.) L.W. Hou, L. Cai & Crous, E. moniliformis (A. Giraldo et al.) L.W. Hou, L. Cai & Crous, E. salmonea (W. Gams & Lodha) L.W. Hou, L. Cai & Crous, E. tubakii (Gams) L.W. Hou, L. Cai & Crous, Fusariella arenula (Berk. & Broome) L.W. Hou, L. Cai & Crous, Hapsidospora chrysogena (Thirum. & Sukapure) L.W. Hou, L. Cai & Crous, H. flava (W. Gams) L.W. Hou, L. Cai & Crous, H. globosa (Malloch & Cain) L.W. Hou, L. Cai & Crous, H. inversa (Malloch & Cain) L.W. Hou, L. Cai & Crous, Hydropisphaera aurantiaca (C.A. Jørg.) L.W. Hou, L. Cai & Crous, Lasionectria atrorubra (Lechat & J. Fourn.) L.W. Hou, L. Cai & Crous, L. bisepta (W. Gams) L.W. Hou, L. Cai & Crous, L. castaneicola (Lechat & Gardiennet) L.W. Hou, L. Cai & Crous, L. cerealis (P. Karst.) L.W. Hou, L. Cai & Crous, L. olida (W. Gams) L.W. Hou, L. Cai & Crous, Lasionectriopsis dentifera (Samuels) L.W. Hou, L. Cai & Crous, Lasionectriella arenuloides (Samuels) L.W. Hou, L. Cai & Crous, La. marigotensis (Lechat & J. Fourn.) L.W. Hou, L. Cai & Crous, Monohydropisphaera fusigera (Berk. & Broome) L.W. Hou, L. Cai & Crous, Musananaesporium tectonae (R.F. Castañeda) L.W. Hou, L. Cai & Crous, Mycocitrus zonatus (Sawada) L.W. Hou, L. Cai & Crous, Nectriopsis microspora (Jaap) L.W. Hou, L. Cai & Crous, Ovicillium asperulatum (A. Giraldo et al.) L.W. Hou, L. Cai & Crous, O. variecolor (A. Giraldo et al.) L.W. Hou, L. Cai & Crous, Paracylindrocarpon multiloculatum (Samuels) L.W. Hou, L. Cai & Crous, Pn. multiseptatum (Samuels)L.W. Hou, L. Cai & Crous, Paragliomastix chiangraiensis (J.F. Li et al.) L.W. Hou, L. Cai & Crous, Px. luzulae (Fuckel) L.W. Hou, L. Cai & Crous, Px. znieffensis (Lechat & J. Fourn.) L.W. Hou, L. Cai & Crous, Protocreopsis rutila (W. Gams) L.W. Hou, L. Cai & Crous, Proxiovicillium blochii (Matr.)L.W. Hou, L. Cai & Crous, Stanjemonium dichromosporum (Gams & Sivasith.) L.W. Hou, L. Cai & Crous, Verruciconidia persicina (Nicot) L.W. Hou, L. Cai & Crous, Ve. verruculosa (W. Gams & Veenb.-Rijks) L.W. Hou, L. Cai & Crous, Waltergamsia citrina (A. Giraldo et al.) L.W. Hou, L. Cai & Crous, W. dimorphospora (A. Giraldo et al.) L.W. Hou, L. Cai & Crous, W. epimycota (Samuels) L.W. Hou, L. Cai & Crous, W. fusidioides (Nicot) L.W. Hou, L. Cai & Crous, W. hennebertii (W. Gams) L.W. Hou, L. Cai & Crous, W. parva (A. Giraldo et al.) L.W. Hou, L. Cai & Crous, W. pilosa (A. Giraldo et al.) L.W. Hou, L. Cai & Crous, W. zeylanica (Petch) L.W. Hou, L. Cai & Crous; Cephalothecaceae: Phialemonium thermophilum (W. Gams & J. Lacey) L.W. Hou, L. Cai & Crous; Clavicipitaceae: Subuliphorum camptosporum (W. Gams) L.W. Hou, L. Cai & Crous; Coniochaetaceae: Coniochaeta psammospora (W. Gams) L.W. Hou, L. Cai & Crous; Nothoacremoniaceae: Nothoacremonium exiguum (W. Gams) L.W. Hou, L. Cai & Crous; Neoacremoniaceae: Neoacremonium minutisporum (Sukapure & Thirum.) L.W. Hou, L. Cai & Crous; Ne. taiwanense (K.L. Pang et al.) L.W. Hou, L. Cai & Crous; Ne. vitellinum (W. Gams) L.W. Hou, L. Cai & Crous; Plectosphaerellaceae: Allomusicillium domschii (W. Gams) L.W. Hou, L. Cai & Crous, Brunneomyces pseudozeylanicus (W. Gams) L.W. Hou, L. Cai & Crous; Pseudoniessliaceae: Pseudoniesslia minutispora (W. Gams et al.) L.W. Hou, L. Cai & Crous; Sarocladiaceae: Chlamydocillium curvulum (W. Gams) L.W. Hou, L. Cai & Crous, Parasarocladium funiculosum (Sukapure & Thirum.) L.W. Hou, L. Cai & Crous; Valsonectriaceae: Valsonectria inflata (C.H. Dickinson) L.W. Hou, L. Cai & Crous, V. roseola (G. Sm.) L.W. Hou, L. Cai & Crous. Epitype (basionym): Sphaeria violacea J.C. Schmidt ex Fr. Neotype (basionym): Mastigocladium blochii Matr. Citation: Hou LW, Giraldo A, Groenewald JZ, Rämä T, Summerbell RC, Zang P, Cai L, Crous PW (2023). Redisposition of acremonium-like fungi in Hypocreales. Studies in Mycology 105: 23-203. doi: 10.3114/sim.2023.105.02.