Protein tyrosine phosphatase 1B (PTP1B) inhibitors from the deep-sea fungus Penicillium chrysogenum SCSIO 07007

Antitumor aspochalasin and antiviral benzofuran derivatives from a marine-derived fungus Aspergillus sp. SCSIO41032

Chemical investigation of the EtOAc extract of a deep-sea derived fungus Aspergillus sp. SCSIO41032 resulted in the isolation of ten known compounds, including eight aspochalasins. Their structures were elucidated by using extensive NMR spectroscopic, mass spectrometric and single crystal X-ray diffraction analysis. The detailed crystallographic data for structures 1, 2, and 4, along with the relative configurations of aspochalasin E (3) determined by its acetonide derivative were reported for the first time. The results of antitumor and antiviral activities showed that 3 displayed moderate antitumor activities against 22Rv1, PC-3, A549, and HCT-15 cell lines with IC50 values ranged from 5.9 ± 0.8 to 19.0 ± 7.7 μM, and 9 exhibited moderate antiviral activities against HSV-1/2 with EC50 values of 9.5 ± 0.5 and 5.4 ± 0.6 μM, respectively. Plate clone formation assays results indicated that 3 inhibited the 22Rv1, PC-3 cells growth in a dose-dependent manner.

New sesquiterpene from a soil fungus of Trichoderma sp

Sixteen secondary metabolites, including one new sesquiterpene (1, named isocyclonerodiol oxide), seven known sesquiterpenes (2-8), two sorbicillinoid polyketides (15, 16), and six known other compounds (9-14) were isolated from the fermentation broth of Trichoderma sp. T-4-1. The structure of 1 was determined by 1 D, 2 D NMR (HMBC, HSQC, 1H-1H COSY, NOESY), and HRESIMS spectra. In addition, sesquiterpenes and sorbicillinoid polyketides showed significant antiviral activities.

New Sorbicillinoids from the Mangrove Endophytic Fungus Trichoderma reesei SCNU-F0042

Three new dimeric sorbicillinoids (1-3) and one new 3,4,6-trisubstituted α-pyrone (5), along with seven analogues (4 and 6-11), were isolated from the mangrove endophytic fungus Trichoderma reesei SCNU-F0042 under the guidance of molecular networking approach. Their chemical structures were established by 1D and 2D NMR HR-ESI-MS and ECD analysis. In a bioassay, compound 2 exhibited moderate SARS-CoV-2 inhibitory activity with an EC50 value of 29.0 μM.

A new quinolone and acetylcholinesterase inhibitors from a sponge-associated fungus Penicillium sp. SCSIO41033

The chemical investigation of the EtOAc extract from the solid rice medium cultured with a sponge-associated fungus Penicillium sp. SCSIO41033 led to the isolation of two quinolones including a new one, penicinolone (1), three xanthone derivatives (3-5), and four anthraquinones (6-9). Their structures were determined by comprehensive analysis of 1H and 13C NMR, COSY, HSQC, and HMBC spectroscopic, and HRESIMS mass spectrometric data. The bioactive assays revealed that compounds 1 and 2 showed no antimicrobial activities against five bacteria and eight fungi, and compounds 5, 8 and 9 exhibited inhibition against AChE with IC50 values of 45.9, 42.5 and 40.5 μg/mL. Molecular docking analysis was performed to explore the interactions between active molecules and AChE protein, which indicated that xanthone and anthraquinone derivatives had the potential for developing AChE inhibitors.

Parameterization and validation of a new AMBER force field for an oxovanadium (IV) complex with therapeutic potential implications in Alzheimer's disease

The scarcity of efficient force fields to describe metal complexes may be a problem for new advances in medicinal chemistry. Thus, the development of force fields for these compounds can be valuable for the scientific community, especially when it comes to molecules that show interesting outputs regarding potential treating of diseases. Vanadium complexes, for instance, have shown promising results towards therapeutics of Alzheimer's Disease, most notably the bis(maltolato)oxovanadium (IV). Therefore, the mainly goal of this work is to develop and validate a new set of parameters for this vanadium complex from a minimum energy structure, obtained by DFT calculations, where great results of the new force field are found when confronted with experimental and quantum reference values. Moreover, the new force field showed to be quite effective to describe the molecule of under study whilst GAFF could not describe it effectively. In addition, a case study points out hydrogen bonds in the vanadium complex-PTP1B system.

Rh(III)-Catalyzed Spiroannulation Reaction of N-Aryl Nitrones with 2-Diazo-1,3-indandiones: Synthesis of Spirocyclic Indole-N-oxides and Their 1,3-Dipolar Cycloaddition with Maleimides

An efficient strategy for the preparation of spirocyclic indole-N-oxide compounds through a Rh(III)-catalyzed [4 + 1] spiroannulation reaction of N-aryl nitrones with 2-diazo-1,3-indandiones as C1 synthons under extremely mild conditions is presented. From this reaction, 40 spirocyclic indole-N-oxides were easily obtained in up to 98% yield. In addition, the title compounds could be successfully used for the construction of structurally intriguing maleimide-containing fused polycyclic scaffolds via a diastereoselective 1,3-dipolar cycloaddition reaction with maleimides.

Acetylcholine Esterase Inhibitory Effect, Antimicrobial, Antioxidant, Metabolomic Profiling, and an In Silico Study of Non-Polar Extract of The Halotolerant Marine Fungus Penicillium chrysogenum MZ945518

Major health issues, such as the rise in oxidative stress, incidences of Alzheimer’s disease, and infections caused by antibiotic-resistant microbes, have prompted researchers to look for new therapeutics. Microbial extracts are still a good source of novel compounds for biotechnological use. The objective of the current work was to investigate marine fungal bioactive compounds with potential antibacterial, antioxidant, and acetylcholinesterase inhibitory effects. Penicillium chrysogenum strain MZ945518 was isolated from the Mediterranean Sea in Egypt. The fungus was halotolerant with a salt tolerance index of 1.3. The mycelial extract showed antifungal properties against Fusarium solani with an inhibitory percentage of 77.5 ± 0.3, followed by Rhizoctonia solani and Fusarium oxysporum with percentages of 52 ± 0.0 and 40 ± 0.5, respectively. The extract also showed antibacterial activity against both Gram-negative and Gram-positive bacterial strains using the agar diffusion technique. The fungal extract was significantly more effective with Proteus mirabilis ATCC 29906 and Micrococcus luteus ATCC 9341; inhibition zones recorded 20 and 12 mm, respectively, compared with the antibiotic gentamycin, which recorded 12 and 10 mm, respectively. The antioxidant activity of the fungus extract revealed that it successfully scavenged DPPH free radicals and recorded an IC50 of 542.5 µg/mL. Additionally, it was capable of reducing Fe3+ to Fe2+ and exhibiting chelating ability in the metal ion-chelating test. The fungal extract was identified as a crucial inhibitor of acetylcholinesterase with an inhibition percentage of 63% and an IC50 value of 60.87 µg/mL. Using gas chromatography–mass spectrometry (GC/MS), 20 metabolites were detected. The most prevalent ones were (Z)-18-octadec-9-enolide and 1,2-Benzenedicarboxylic acid, with ratios of 36.28 and 26.73%, respectively. An in silico study using molecular docking demonstrated interactions between the major metabolites and the target proteins, including: DNA Gyrase, glutathione S-transferase, and Acetylcholinesterase, confirming the extract’s antimicrobial and antioxidant activity. Penicillium chrysogenum MZ945518, a halotolerant strain, has promising bioactive compounds with antibacterial, antioxidant, and acetylcholinesterase inhibitory activities

Molecular and Biological Investigation of Isolated Marine Fungal Metabolites as Anticancer Agents: A Multi-Target Approach

Cancer is the leading cause of death globally, with an increasing number of cases being annually reported. Nature-derived metabolites have been widely studied for their potential programmed necrosis, cytotoxicity, and anti-proliferation leading to enrichment for the modern medicine, particularly within the last couple of decades. At a more rapid pace, the concept of multi-target agents has evolved from being an innovative approach into a regular drug development procedure for hampering the multi-fashioned pathophysiology and high-resistance nature of cancer cells. With the advent of the Red Sea Penicillium chrysogenum strain S003-isolated indole-based alkaloids, we thoroughly investigated the molecular aspects for three major metabolites: meleagrin (MEL), roquefortine C (ROC), and isoroquefortine C (ISO) against three cancer-associated biological targets Cdc-25A, PTP-1B, and c-Met kinase. The study presented, for the first time, the detailed molecular insights and near-physiological affinity for these marine indole alkaloids against the assign targets through molecular docking-coupled all-atom dynamic simulation analysis. Findings highlighted the superiority of MEL's binding affinity/stability being quite in concordance with the in vitro anticancer activity profile conducted via sulforhodamine B bioassay on different cancerous cell lines reaching down to low micromolar or even nanomolar potencies. The advent of lengthy structural topologies via the metabolites' extended tetracyclic cores and aromatic imidazole arm permitted multi-pocket accommodation addressing the selectivity concerns. Additionally, the presence decorating polar functionalities on the core hydrophobic tetracyclic ring contributed compound's pharmacodynamic preferentiality. Introducing ionizable functionality with more lipophilic characters was highlighted to improve binding affinities which was also in concordance with the conducted drug-likeness/pharmacokinetic profiling for obtaining a balanced pharmacokinetic/dynamic profile. Our study adds to the knowledge regarding drug development and optimization of marine-isolated indole-based alkaloids for future iterative synthesis and pre-clinical investigations as multi-target anticancer agents.

Deep-Sea Natural Products from Extreme Environments: Cold Seeps and Hydrothermal Vents

The deep sea has been proven to be a great treasure for structurally unique and biologically active natural products in the last two decades. Cold seeps and hydrothermal vents, as typical representatives of deep-sea extreme environments, have attracted more and more attention. This review mainly summarizes the natural products of marine animals, marine fungi, and marine bacteria derived from deep-sea cold seeps and hydrothermal vents as well as their biological activities. In general, there were 182 compounds reported, citing 132 references and covering the literature from the first report in 1984 up to March 2022. The sources of the compounds are represented by the genera Aspergillus sp., Penicillium sp., Streptomyces sp., and so on. It is worth mentioning that 90 of the 182 compounds are new and that almost 60% of the reported structures exhibited diverse bioactivities, which became attractive targets for relevant organic synthetic and biosynthetic studies.

Penicillium chrysogenum, a Vintage Model with a Cutting-Edge Profile in Biotechnology

The discovery of penicillin entailed a decisive breakthrough in medicine. No other medical advance has ever had the same impact in the clinical practise. The fungus Penicillium chrysogenum (reclassified as P. rubens) has been used for industrial production of penicillin ever since the forties of the past century; industrial biotechnology developed hand in hand with it, and currently P. chrysogenum is a thoroughly studied model for secondary metabolite production and regulation. In addition to its role as penicillin producer, recent synthetic biology advances have put P. chrysogenum on the path to become a cell factory for the production of metabolites with biotechnological interest. In this review, we tell the history of P. chrysogenum, from the discovery of penicillin and the first isolation of strains with high production capacity to the most recent research advances with the fungus. We will describe how classical strain improvement programs achieved the goal of increasing production and how the development of different molecular tools allowed further improvements. The discovery of the penicillin gene cluster, the origin of the penicillin genes, the regulation of penicillin production, and a compilation of other P. chrysogenum secondary metabolites will also be covered and updated in this work.

New α-pyrone derivatives with herbicidal activity from the endophytic fungus Alternaria brassicicola

Three pairs of undescribed enantiomeric α-pyrone derivatives (1a/1b-3a/3b) and six undescribed congeners (4-9), were obtained from the fungus Alternaria brassicicola that was isolated from the fresh leaves of Siegesbeckia pubescens Makino (Compositae). The structures of these new compounds were characterized by extensive NMR spectroscopic and HRESIMS data, and their absolute configurations were further elucidated by a modified Mosher's method, chemical conversion, single-crystal X-ray diffraction analysis, and ECD calculations. This is the first report of three pairs of enantiomeric α-pyrone derivatives from the fungus A. brassicicola, and these enantiomers were successfully acquired from scalemic mixtures via chiral HPLC. Compounds 1a/1b-3a/3b and 4-9 were evaluated for the herbicidal activity against Echinochloa crusgalli, Setaria viridis, Portulaca oleracea, and Taraxacum mongolicum. At a concentration of 100 μg/mL, compounds 1a and 1b could significantly inhibit the germination of monocotyledon weed seeds (E. crusgalli and S. viridis) with inhibitory ratios ranging from 68.6 ± 6.4% to 84.2 ± 5.1%, which was equivalent to that of the positive control (glyphosate). The potential structure-herbicidal activity relationship of these compounds was also discussed. To a certain extent, the results of this study will attract great interest for the potential practical application of promising fungal metabolites, α-pyrone derivatives, as ecofriendly herbicides.

A Treasure of Bioactive Compounds from the Deep Sea

The deep-sea environment is a unique, challenging extreme habitat where species have had to adapt to the absence of light, low levels of oxygen, high pressure and little food. In order to survive such harsh conditions, these organisms have evolved different biochemical and physiological features that often have no other equivalent in terrestrial habitats. Recent analyses have highlighted how the deep sea is one of the most diverse and species-rich habitats on the planet but less explored compared to more accessible sites. Because of their adaptation to this extreme environment, deep-sea species have the potential to produce novel secondary metabolites with potent biological activities. Recent advances in sampling and novel techniques in microorganism culturing and chemical isolation have promoted the discovery of bioactive agents from deep-sea organisms. However, reports of natural products derived from deep-sea species are still scarce, probably because of the difficulty in accessing deep-sea samples, sampling costs and the difficulty in culturing deep-sea organisms. In this review, we give an overview of the potential treasure represented by metabolites produced by deep marine species and their bioactivities for the treatment and prevention of various human pathologies.

Structures and Biological Activities of Diketopiperazines from Marine Organisms: A Review

Diketopiperazines are potential structures with extensive biological functions, which have attracted much attention of natural product researchers for a long time. These compounds possess a stable six-membered ring, which is an important pharmacophore. The marine organisms have especially been proven to be a wide source for discovering diketopiperazine derivatives. In recent years, more and more interesting bioactive diketopiperazines had been found from various marine habitats. This review article is focused on the new 2,5-diketopiperazines derived from marine organisms (sponges and microorganisms) reported from the secondary half-year of 2014 to the first half of the year of 2021. We will comment their chemical structures, biological activities and sources. The objective is to assess the merit of these compounds for further study in the field of drug discovery.

Untargeted Metabolomics Approach for the Discovery of Environment-Related Pyran-2-ones Chemodiversity in a Marine-Sourced Penicillium restrictum

Very little is known about chemical interactions between fungi and their mollusc host within marine environments. Here, we investigated the metabolome of a Penicillium restrictum MMS417 strain isolated from the blue mussel Mytilus edulis collected on the Loire estuary, France. Following the OSMAC approach with the use of 14 culture media, the effect of salinity and of a mussel-derived medium on the metabolic expression were analysed using HPLC-UV/DAD-HRMS/MS. An untargeted metabolomics study was performed using principal component analysis (PCA), orthogonal projection to latent structure discriminant analysis (O-PLSDA) and molecular networking (MN). It highlighted some compounds belonging to sterols, macrolides and pyran-2-ones, which were specifically induced in marine conditions. In particular, a high chemical diversity of pyran-2-ones was found to be related to the presence of mussel extract in the culture medium. Mass spectrometry (MS)- and UV-guided purification resulted in the isolation of five new natural fungal pyran-2-one derivatives—5,6-dihydro-6S-hydroxymethyl-4-methoxy-2H-pyran-2-one (1), (6S, 1’R, 2’S)-LL-P880β (3), 5,6-dihydro-4-methoxy-6S-(1’S, 2’S-dihydroxy pent-3’(E)-enyl)-2H-pyran-2-one (4), 4-methoxy-6-(1’R, 2’S-dihydroxy pent-3’(E)-enyl)-2H-pyran-2-one (6) and 4-methoxy-2H-pyran-2-one (7)—together with the known (6S, 1’S, 2’S)-LL-P880β (2), (1’R, 2’S)-LL-P880γ (5), 5,6-dihydro-4-methoxy-2H-pyran-2-one (8), (6S, 1’S, 2’R)-LL-P880β (9), (6S, 1’S)-pestalotin (10), 1’R-dehydropestalotin (11) and 6-pentyl-4-methoxy-2H-pyran-2-one (12) from the mussel-derived culture medium extract. The structures of 1-12 were determined by 1D- and 2D-MMR experiments as well as high-resolution tandem MS, ECD and DP4 calculations. Some of these compounds were evaluated for their cytotoxic, antibacterial, antileishmanial and in-silico PTP1B inhibitory activities. These results illustrate the utility in using host-derived media for the discovery of new natural products.

Cellular Signal Transductions and Their Inhibitors Derived from Deep-Sea Organisms

Not only physiological phenomena but also pathological phenomena can now be explained by the change of signal transduction in the cells of specific tissues. Commonly used cellular signal transductions are limited. They consist of the protein-tyrosine kinase dependent or independent Ras-ERK pathway, and the PI3K-Akt, JAK-STAT, SMAD, and NF-κB-activation pathways. In addition, biodegradation systems, such as the ubiquitin-proteasome pathway and autophagy, are also important for physiological and pathological conditions. If we can control signaling for each by a low-molecular-weight agent, it would be possible to treat diseases in new ways. At present, such cell signaling inhibitors are mainly looked for in plants, soil microorganisms, and the chemical library. The screening of bioactive metabolites from deep-sea organisms should be valuable because of the high incidence of finding novel compounds. Although it is still an emerging field, there are many successful examples, with new cell signaling inhibitors. In this review, we would like to explain the current view of the cell signaling systems important in diseases, and show the inhibitors found from deep-sea organisms, with their structures and biological activities. These inhibitors are possible candidates for anti-inflammatory agents, modulators of metabolic syndromes, antimicrobial agents, and anticancer agents.

Structurally various sorbicillinoids from the deep-sea sediment derived fungus Penicillium sp. SCSIO06871

Two new hybrid sorbicillinoids (1 and 5), three new bisorbicillinoids (2-4), and three monomeric sorbicillinoids (6-8), along with eighteen known sorbicillinoids (9-26) were isolated from cultures of the deep-sea sediment derived fungus Penicillium sp. SCSIO06871. Their structures and absolute configurations were elucidated based upon the extensive spectroscopic analysis, X-ray crystallography analysis and the comparison of the experimental and calculated ECD data. Bisorbicillpyrone A (4) is the first example of bisorbicillinoid containing an α-pyrone derivative unit. All of the isolated compounds were evaluated for their antibacterial, antifungal and enzyme inhibitory activities against α-glycosidase and acetylcholinesterase (AChE) in vitro. Compound 6 displayed more potent inhibitory activity against α-glycosidase than acarbose with IC₅₀ value of 36.0 μM and compounds 4, 12, 18, 22, 23 exhibited moderate inhibitory activity with IC₅₀ values ranging from 115.8 to 208.5 μM. Compounds 10 and 22 showed weak enzyme inhibitory activities against AChE with 55.1% and 51.1% inhibitions at concentration of 50 μg/mL, respectively. Besides, compounds 11 and 12 exhibited significant antibacterial activities against Staphylococcus aureus with MIC values of 10.0 and 5.0 μg/mL, respectively. The hypothetical biosynthetic pathway of the isolated sorbicillinoids with three different structural types was discussed.

Identification and Characterization of a New Type III Polyketide Synthase from a Marine Yeast, Naganishia uzbekistanensis

A putative Type III Polyketide synthase (PKSIII) encoding gene was identified from a marine yeast, Naganishia uzbekistanensis strain Mo29 (UBOCC-A-208024) (formerly named as Cryptococcus sp.) isolated from deep-sea hydrothermal vents. This gene is part of a distinct phylogenetic branch compared to all known terrestrial fungal sequences. This new gene encodes a C-terminus extension of 74 amino acids compared to other known PKSIII proteins like Neurospora crassa. Full-length and reduced versions of this PKSIII were successfully cloned and overexpressed in a bacterial host, Escherichia coli BL21 (DE3). Both proteins showed the same activity, suggesting that additional amino acid residues at the C-terminus are probably not required for biochemical functions. We demonstrated by LC-ESI-MS/MS that these two recombinant PKSIII proteins could only produce tri- and tetraketide pyrones and alkylresorcinols using only long fatty acid chain from C8 to C16 acyl-CoAs as starter units, in presence of malonyl-CoA. In addition, we showed that some of these molecules exhibit cytotoxic activities against several cancer cell lines.

Bioactive secondary metabolites from the deep-sea derived fungus Aspergillus sp. SCSIO 41029

Two new compounds classified as one new lumazine peptide, penilumamide K (1) and one new sesquiterpene (2), were obtained from the deep-sea derived fungus Aspergillus sp. SCSIO 41029, together with eleven known compounds (3-13). The structures of 1-13 including absolute configurations were determined by detailed NMR spectroscopy, HR-ESI-MS, chemical derivatization, and optical rotation data. Among them, compound 1 represents the first lumazine peptide reported from deep-sea derived fungus. The bioactive assay exhibited that compounds 1, 3, 4, 5, 7 and 10 had significant potency against α-glucosidase with IC₅₀ values ranging from 18.61 to 109.06 μΜ. In addition, compounds 4 and 9 showed strong antibacterial activity against Staphylococcus aureus with MIC values of 0.78 and 6.25 μg ml^-1, respectively.

Lanostane Triterpenoids with PTP1B Inhibitory and Glucose-Uptake Stimulatory Activities from Mushroom Fomitopsis pinicola Collected in North America

A chemical investigation on the fruiting bodies of Fomitopsis pinicola led to the isolation and identification of 28 lanostane triterpenoids including 11 new compounds (1-11) and 17 known analogues (12-28). Their structures were elucidated by extensive one-dimensional NMR, two-dimensional NMR, and MS spectra. All isolates were tested for their anti-inflammatory activity, protein tyrosine phosphatase 1B (PTP1B) inhibitory activity in vitro, and effect on glucose uptake in insulin-resistant HepG2 cells. Compounds 1, 4, 22, 23, and 27 inhibited the nitric oxide released from the LPS-induced RAW 264.7 cell assay with IC₅₀ values in the range of 21.4-27.2 μM. Compounds 18, 22, 23, and 28 showed strong PTP1B inhibitory activity with IC₅₀ values in the range of 20.5-29.9 μM, comparable to that of the positive control of oleanolic acid (15.0 μM). Compounds 18 and 22 were confirmed to be good competitive inhibitors of PTP1B by kinetic analysis. In addition, compounds 18, 22, and 28 were found to stimulate glucose uptake in the insulin-resistant HepG2 cells in the dose from 6.25 to 100 μM. These findings indicated the potential of F. pinicola in the development of functional food or medicine for the prevention and treatment of diabetes.