Bioactive Aspergteroids G-J from Soft-Coral-Associated Symbiotic and Epiphytic Fungus Aspergillus terreus EGF7-0-1

Two new disubstituted maleimides, aspergteroids G-H (1-2), and two trisubstituted butenolides aspergteroids I-J (3-4), along with four known analogs, were isolated and structurally identified from the fermentation extract of soft-coral-associated symbiotic and epiphytic fungus Aspergillus terreus EGF7-0-1. The structures of the new compounds were established mainly via spectroscopic data analyses, and their absolute configurations were determined via X-ray diffraction analysis and comparison of the calculated and experimental electronic circular dichroism. Myocardial protection assays showed that compounds 1, 2, 5, and 6 possess protective effects against tert-butyl hydroperoxide (TBHP)-induced H9c2 (rat myocardial cells) apoptosis at low concentrations. Based on the analyses of the protein-protein interaction (PPI) network and Western blotting, compound 1 may inhibit the apoptosis and inflammatory response of cardiomyocytes after TBHP induction and improve the antioxidant capacity of cardiomyocytes. We speculate that the anti-inflammatory response of compound 1 is suppressed by the glycogen synthase kinase-3 beta (GSK-3β), downregulated by the NOD-like receptor thermal protein domain associated protein 3 (NLRP3) inflammasome activation, and suppressed by the expression of cysteinyl aspartate specific proteinase-3 (caspase-3) and B-cell lymphoma-2 associated X protein (Bax).

Unearthing the fungal endophyte Aspergillus terreus for chemodiversity and medicinal prospects: a comprehensive review

Aspergillus terreus microorganism represents a promising prospective source for drug discovery since it is rich in diverse kinds of bioactive secondary metabolites. It contributed to many biotechnological applications and its metabolites are used in the synthesis of certain pharmaceuticals and food products, in addition to its useful uses in fermentation processes. There are about 346 compounds identified from marine and terrestrial-derived A. terreus from 1987 until 2022, 172 compounds of them proved a vast array of bioactivity. This review aimed to create an up-to-date comprehensive literature data of A. terreus's secondary metabolites classes supported by its different bioactivity data to be a scientific record for the next work in drug discovery.

In Vitro Efficacy of Extracts and Isolated Bioactive Compounds from Ascomycota Fungi in the Treatment of Colorectal Cancer: A Systematic Review

Colorectal cancer (CRC) is the second leading cause of cancer-related deaths worldwide. Despite the advances and success of current treatments (e.g., chemotherapy), there are multiple serious side effects which require the development of new treatment strategies. In recent years, fungi have gained considerable attention as a source of extracts and bioactive compounds with antitumor capabilities because of their antimicrobial and antioxidant properties and even their anti-inflammatory and antiviral activities. In the present review, a systematic search of the existing literature in four electronic databases was carried out in which the antitumor activity against CRC cells of Ascomycota fungi extracts or compounds was tested. The systematical research in the four databases resulted in a total of 883 articles. After applying exclusion and inclusion criteria, a total of 75 articles were finally studied. The order Eurotiales was the most studied (46% of the articles), and the ethyl acetate extraction was the most used method (49% of the papers). Penicillium extracts and gliotoxin and acetylgliotoxin G bioactive compounds showed the highest cytotoxic activity. This review also focuses on the action mechanisms of the extracts and bioactive compounds of fungi against CRC, which were mediated by apoptosis induction and the arrest of the cell cycle, which induces a notable reduction in the CRC cell proliferation capacity, and by the reduction in cell migration that limits their ability to produce metastasis. Thus, the ability of fungi to induce the death of cancer cells through different mechanisms may be the basis for the development of new therapies that improve the current results, especially in the more advanced stages of the CCR.

γ-Aromatic Butenolides of Microbial Source - A Review of Their Structures, Biological Activities and Biosynthesis

γ-Aromatic butenolides (γ-AB) are an important type of structures found in many bioactive microbial secondary metabolites (SMs). γ-AB refer to a group of natural products (NPs) containing five-membered (unsaturated) lactones with 3-phenyl and 4-benzyl substituents. Their wide-range biological activities have inspired pharmaceutical chemists to explore its biosynthesis mechanisms and design strategies to construct the γ-AB skeleton. Recently, there are a great deal of interesting research progress on the structures, biological activities and biosynthesis of γ-AB. This review will focus on these aspects and summarize the important achievements of γ-AB from 1975 to 2021.

Isolation of Thioinosine and Butenolides from a Terrestrial Actinomycetes sp. GSCW-51 and Their in Silico Studies for Potential against SARS-CoV-2

In our continuous screening for bioactive microbial natural products, the culture extracts of a terrestrial Actinomycetes sp. GSCW-51 yielded two new metabolites, i. e., 5-hydroxymethyl-3-(1-hydroxy-6-methyl-7-oxooctyl)dihydrofuran-2(3H)-one (1), 5-hydroxymethyl-3-(1,7-dihydroxy-6-methyloctyl)dihydrofuran-2(3H)-one (2), and two known compounds; 5'-methylthioinosine (3), and 5'-methylthioinosine sulfoxide (4), which are isolated first time from any natural source, along with four known compounds (5-8). The structures of the new compounds were deduced by HR-ESI-MS, 1D and 2D NMR data, and in comparison with related compounds from the literature. Additionally, owing to the current COVID-19 pandemic situation, we also computationally explored the therapeutic potential of our isolated compounds against SARS-CoV-2. Compound 4 showed the best binding energies of -6.2 and -6.6 kcal/mol for Mpro and spike proteins, respectively. The intermolecular interactions were also studied using 2-D and 3-D imagery, which also supported the binding energies as well as put several insights under the spotlight. Furthermore, Lipinski's rule of 5 was used to predict the drug likeness of compounds 1-4, which indicated all compounds obey Lipinski's rule of 5. The study of bioavailability radars of the compounds 1-4 also confirmed their drug likeness properties where all the five crucial drug likeness parameters are in color area, which is safe to be used as drugs. Our isolation and computational findings highly encourage the scientific community to do further in vitro and in vivo studies of compounds 1-4.

Asperimides A-D, anti-inflammatory aromatic butenolides from a tropical endophytic fungus Aspergillus terreus

Four new aromatic butenolides, asperimides A-D (1-4), together with a known analogue, butyrolactone I (5), were isolated from solid cultures of a tropical endophytic fungus Aspergillus terreus. The structures of these compounds were elucidated on the basis of spectroscopic methods and electronic circular dichroism calculations. Compounds 1-4 represent the first examples of butenolides with a maleimide core isolated from Aspergillus sp. Inhibitory effects of the isolated compounds on nitric oxide production were investigated in lipopolysaccaride (LPS)-mediated RAW 264.7 cells. Compounds 3 and 4 exhibited potent anti-inflammatory with IC₅₀ values of 0.78 ± 0.06 and 1.26 ± 0.11 μM, respectively.

New butenolide derivatives from the marine sponge-derived fungus Aspergillus terreus

Two new butenolide derivatives (±)-asperteretal D ((±)-1) and asperteretal E (2) containing rare 2-benzyl-3-phenyl substituted lactone core, together with nine known analogues (3-11) were obtained from a fungus Aspergillus terreus derived from the marine sponge Phakellia fusca. All the structures were elucidated on the basis of extensive NMR spectroscopic data. The chiral chromatography analyses allowed the separation of the (±)-asperteretal D, of which the absolute configurations were determined by comparing the experimental to calculated electronic circular dichroic (ECD) spectra. Compounds (±)-1, 2-5, and 7 exhibited potent inhibitory activities against α-glucosidase with IC₅₀ values ranging from 8.65 to 20.3 µM (positive control acarbose with an IC₅₀ value of 320 µM). In addition, derivatives 5-8 also showed moderate antioxidant activities.

Fumigaclavine I, a new alkaloid isolated from endophyte Aspergillus terreus

The present study was designed to isolate and purify chemical constituents from solid culture of endophyte Aspergillus terreus LQ, using silica gel column chromatography, gel filtration with Sephadex LH-20, and HPLC. Fumigaclavine I (1), a new alkaloid, was obtained, along with seven known compounds, including fumigaclavine C (2), rhizoctonic acid (3), monomethylsulochrin (4), chaetominine (5), spirotryprostatin A (6), asperfumoid (7), and lumichrome (8). The structure of compound 1 was elucidated by various spectroscopic analyses (UV, MS, 1D and 2D NMR). The in vitro cytotoxicity of compound 1 was determined by MTT assay in human hepatocarcinoma cell line SMMC-7721, showing weaker cytotoxicity, compared with cisplatin, a clinically used cancer chemotherapeutic agent.

Butenolide derivatives from the plant endophytic fungus Aspergillus terreus

Three new butenolides containing 5-hydroxyfuran-2(5H)-one core, asperteretal A (1), asperteretal B (2), and asperteretal C (3), together with seven known butenolides (4-10), were obtained from an endophytic fungus Aspergillus terreus PR-P-2 isolated from the plant Camellia sinensis var. assamica. The structures of compounds 1-3 were elucidated on the basis of detailed spectroscopic analysis including UV, IR, HRESIMS, 1D and 2D NMR, and ECD spectra. Compounds 1, 3, 5 and 6-8 showed potent inhibitory effects on NO production in RAW 264.7 lipopolysaccharide-induced macrophages, and compounds 5 and 8 also exhibited moderate cytotoxicity against HL-60 cell line.