Azaphilones: chemistry and biology

Sclerotiorin-Type Azaphilones Isolated from a Marine-Derived Fungus Microsphaeropsis arundinis P1B

Seven pairs of new epimers, microsphazaphilones A-G (1, 3, 5, 7, 9, 11, and 13) and epimicrosphazaphilones A-G (2, 4, 6, 8, 10, 12, and 14), were isolated and identified from the fermentation of a marine-derived fungus Microsphaeropsis arundinis P1B. Their structures, including the absolute configurations, were determined by NMR and MS data analysis, comparison of experimental and calculated electronic circular dichroism (ECD) curves, and dimolybdenum tetraacetate induced ECD. Microsphazaphilones A-G and epimicrosphazaphilones A-G represent the sclerotiorin-type azaphilones with a rare γ-lactone or a tetrahydrofuran fragment at the end of the branched C7 side chain at the C-3 position of the pyranoquinone core skeleton. Among them, compound 2 demonstrated the strongest anti-inflammatory activity that inhibited the expression of multiple inflammatory factors in LPS-induced Raw264.7 cells, possibly through the inhibition of the Erk1/2 MAPK signaling pathway.

Isolation of 6,7-iso-Felinone A: A Configurational Reinvestigation of Related Fungal Metabolites

An azaphilone, 6,7-iso-felinone A (2), was isolated from Diaporthales sp. KT3922 along with the known felinone A (1). While compound 2 exhibited weak Cotton effects, its naphthoate derivative (2a) displayed pronounced Cotton effects, enabling the determination of its absolute configuration through electronic circular dichroism (ECD) spectral analysis. Interestingly, the spectroscopically derived relative structure of compound 2 proved identical to previously reported hypoillexidiol (3) and xylariphilone (4). However, substantial differences in 1H nuclear magnetic resonance data among these compounds warranted structural reinvestigation of the entire series, including the structurally related fungal metabolites, fusaraisochromenone (5) and aspergillusone C (6). Comparative analysis revealed identical relative configurations of compounds 1, 3, 4, and 5. Furthermore, compounds 1 and 3 were determined to have an identical absolute configuration, whereas the absolute configuration of compound 4 remained inconclusive due to a significant mismatch in its ECD spectral profile compared to compound 1. Compound 5 was identified as the enantiomer of compounds 1 and 3. Additionally, we discussed the stereochemistry of the 6,7-cis-diol isomer, aspergillusone C (6).

Gold(I)-catalyzed tandem cyclization/peroxidation of 2-alkynyl-1-carbonylbenzenes with TBHP

A gold(I)-catalyzed tandem cyclization/peroxidation of 2-alkynyl-1-carbonylbenzenes with tert-butyl hydroperoxide (TBHP) has been successfully developed to access 1-peroxidized 1H-isochromene derivatives in moderate to good yields. The use of one of the resultant 1-peroxidized 1H-isochromenes (3a) for the construction of phenyl(8-phenylbicyclo[4.2.0]octa-1(6),2,4,7-tetraen-7-yl)methanone (4), phenyl(3-phenyl-1,3-dihydroisobenzofuran-1-yl)methanone (5) and 2-(2-benzoylphenyl)-1-phenylethan-1-one (6) has also been investigated, respectively.

Bioactive hydrogenated azaphilones from acid-tolerant fungus Penicillium purpureum OUCMDZ-019

Two new hydrogenated azaphilones (1 and 2), together with the known azaphilone (3) were isolated from the red soil-derived acid-tolerant fungus Penicillium purpureum OUCMDZ-019 by OSMAC (one strain many compounds) strategy. Their structures were determined by nuclear magnetic resonance (NMR) spectroscopy analysis and electronic circular dichroism (ECD) calculations. Compound 1 was the first reported azaphilone that salified with pyridine and chlorination occurred at C-1, and it exhibited potential inhibitory activity on melanin production as tyrosinase inhibitor in vivo. Furthermore, (+)-mitorubrinol acetate (3) showed significantly inhibitory activity against H1N1 with IC50 values of 58.6 μM (ribavirin, IC50 85.0 μM) as the first report.

Palladium-Catalyzed Enantioselective Tandem Phosphinolation/Cyclization of ortho-Alkynylbenzaldehydes and H-Phosphine Oxides: Access to C1-Phosphinoylated 1H-Isochromenes

A novel and effective method for the synthesis of chiral C1-phosphinoylated 1H-isochromenes has been developed. The reaction proceeds via a tandem asymmetric addition/cyclization under a catalytic system of Pd(OAc)2, a Josiphos-based ligand L9, and ZnCl2 in MeCN at 70 °C. This method demonstrates a broad substrate scope (27 examples), delivering excellent yields (up to 92%) and enantioselectivities (up to 95%).

Brønsted acid-catalyzed two-component tandem condensation and cycloisomerization to 6(2H)-isoquinolinones

An attractive Brønsted acid-catalyzed two-component reaction of 2-alkynyl-4-hydroxybenzaldehydes 1 and primary amines 2 to various 6(2H)-isoquinolinones 3 has been developed. This catalytic system realized an efficient tandem condensation and cycloisomerization reaction to 6(2H)-isoquinolinones 3 in good to excellent yields via a one-pot synthesis, in which two different kinds of C-N bonds were constructed in a straightforward manner. Remarkably, the reaction tolerated various aliphatic, aryl-substituted amines, including chiral amino alcohols and amino acids. The practicality of this approach rendered it a viable alternative for the construction of various 6(2H)-isoquinolinones.

The fungal natural product class of the sorbicillinoids: structures, bioactivities, biosynthesis, and synthesis

Covering 1948 up to October 2024Sorbicillinoids are a growing class of natural products (NPs) that stem from a variety of fungi including members of the orders Hypocreales and Eurotiales. This compound class is unique in its combination of structural complexity and pharmaceutically relevant biological activities. The majority of the sorbicillinoids, which are named after the common hexaketide precursor sorbicillin, exhibit anti-inflammatory, antimicrobial, cytotoxic, phytotoxic, and other selective enzyme inhibitory activities. Over the last eight decades, more than 170 sorbicillinoids, many with strong pharmaceutical potential, have been isolated and described in the literature. This review aims to provide an overview of the structural diversity, biosynthetic pathways, and synthetic studies of this exceptional NP class.

Asptertides A-H, C13-Polyketides From a Marine-Derived Aspergillus terreus

In the present study, 11 C13-polyketides comprising a monocyclic skeleton of an aromatic (1-6 and 11) or a cyclohexanone moiety (7) and an oxygenated bicyclic nucleus (8-10) were isolated from a mutated strain of endophytic fungus Aspergillus terreus RA2905. Five pairs of enantiomers (2a/b-5a/b and 7a/b) were achieved by chiral-phase HPLC separation. The structures of previously unreported asptertides A-H (1-8) were determined by analysis of the spectroscopic data and electronic circular dichroism (ECD) calculations. 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical-scavenging bioassays revealed that some compounds showed moderate antioxidant effects, with IC50 values ranging from 13.7 to 35.6 µM.

Cytochalasins and orsellinic acid derivatives with cytotoxicity from the soil-derived fungus Trichocladium asperum

Four undescribed cytochalasins (1-4), three undescribed orsellinic acid derivatives (5-7) and two known metabolites including methyl lecanorate (8) and methyl orsellinate (9) were isolated from the solid-state cultivation of a soil-derived fungus Trichocladium asperum SQ2-3 collected in Qinghai-Tibet Plateau. Their structures were elucidated by analysis of NMR (1D and 2D) and mass spectrometry data. The absolute configurations of 1-7 were assigned by a combination of the modified Mosher's method, microscale derivatization and Mo2(OAc)4-induced circular dichroism experiment. Compounds 1, 2, 3 and 6 showed significant cytotoxicity against HL-60, A3494, SMMC-7721, MDA-MB-231 and SW480 cell lines with IC50 values ranging from 4.74 to 15.84 μM, respectively. Meanwhile, compound 1 could obviously damage mitochondrial membrane potential and induce G2/M cell cycle arrest in A549 cells.

Purified Monascus Pigments: Biological Activities and Mechanisms of Action

Monascus pigments having yellow, orange, and red colors are widely studied for their potential beneficial properties. Many different biological activities have been reported regarding Monascus pigments and their derivatives, but the usual method is to test complex extracts from the mycelium of the fungus or from a fungus-fermented substrate. However, this review is mainly concerned with the biological activities of purified Monascus pigments. Both yellow (ankaflavin, monascin) and red (rubropunctamine, monascorubramine) Monascus pigments are proven antioxidants if used in concentrations of 10 μg/mL or higher. Antimicrobial activity against Gram-positive and Gram-negative bacteria and fungi has been observed with all Monascus pigments. However, the best antimicrobials are red Monascus pigments, and their amino acid derivatives (l-cysteine derivatives have MIC 4 μg/mL against Enterococcus faecalis). Yellow monaphilones and orange monaphilols seem to have the highest anti-inflammatory activity (IC50 1.7 μM of monaphilol D) and, together with red Monascus pigment derivatives, have mild antiobesity and antidiabetic activities. Further, monascin and ankaflavin in daily doses of 0.5 and 0.08 mg, respectively, lowered serum blood levels of low-density lipoprotein cholesterol complexes in rats on a high-fat diet. Orange Monascus pigments, rubropunctatin and monaphilols A and C, exhibit cytotoxic and antitumor activities (IC50 8-10 μM).

Copper-Catalyzed Domino Phosphorylation/Cyclization of ortho-Alkynylketones for Accessing Phosphorylated 1H-Isochromenes

An effective and economical copper-catalyzed approach for the synthesis of phosphorylated 1H-isochromenes is reported. This method is the first example of focus on ketone phosphonylation to establish a C-P bond and 6-endo-dig cyclization to construct a C-O bond between aryl- and alkyl-substituted alkynylketones and H-phosphinate esters, H-phosphites, and H-phosphine oxides, resulting in chemo- and regioselective phosphorylated 1H-isochromenes with moderate to excellent yields under smooth reaction conditions.

Quantum chemical investigation of electronic transitions of mitorubrin azaphilones

Fungal azaphilones are a broad class of naturally-occurring pigments with diverse applications. Among the azaphilone pigments, mitorubrins are well recognized for their antiviral, antibacterial, antifungal, antiprotozoal, antidiabetic, and antiaging activities in addition to their well-known yellow-orange color. This makes these pigments interesting candidates for use in foods, as cosmetics, and as medicines. In particular, if it is desired to modify the properties of mitorubrin-based pigments, for example by derivatization, it is essential to have an understanding of the electronic spectra of the parent molecules. We have therefore undertaken a computational study of a series of mitorubrins, comparing our computed results with experimental UV/visible spectra. Both density-functional theory (DFT) and coupled-cluster (CC2) methods have been used, and in general, the results are in very good agreement with observation. In order to provide a simple and useful picture of the spectra we analyze the stronger transitions in terms of natural transition orbitals (NTOs).

Evaluation of Monascus purpureus fermentation in dairy sludge-based medium for enhanced production of vibrant red pigment with minimal citrinin content

This study aimed to explore the production of red pigment from Monascus purpureus in waste culture medium and its potential health benefits. Subsequently, the M. purpureus cultivated in a medium containing dairy sludge as waste, the extracted pigment was purified, and subjected to various analyses, including liquid chromatography mass spectrometry (LCMS) and nuclear magnetic resonance (NMR) to verify its purity, high-pressure liquid chromatography (HPLC) to measure the citrinin levels, microbial, and antioxidant activity. Finally, fermentation was conducted in a batch system using a fermenter. M. purpureus was grown in a medium composed of dairy sludge, monosodium glutamate, and glucose, resulting in a biomass yield of 26.15 g/L. After extraction and purification, the sample yielded 4.85 g of dry color. Analysis confirmed the purity of the pigment by LCMS and NMR and revealed low citrinin levels by HPLC. In the fermenter, the sample obtained from enriched culture conditions displayed the highest concentration of monascorubramine, maximum specific growth rate of 0.029/1/h, a cell yield (Yx/s) of 0.29 g/g, and a production efficiency of 65% for M. purpureus. The produced pigment sample showed potential for use in the food industry due to its low citrinin content and high concentration of red pigment.

A New Azaphilone From the Marine Sponge-Associated Fungus Botryosporium pulchrum

A new azaphilone, botryazaphilone (1), the first example of azaphilone featuring a 6/6/5/5 tetracyclic system, together with two known ones, chermesinone A (2) and perangustol B (3), had been obtained from the marine sponge-associated fungus Botryosporium pulchrum. The structure of 1 was elucidated through the analysis of spectroscopic data, whereas its absolute configuration was determined via single-crystal x-ray diffraction. It is the first report of the secondary metabolites isolated from the genus Botryosporium. Furthermore, all the compounds showed potential anti-inflammatory activities on the model of CuSO4-induced transgenic zebrafish.

Naphthoquinone Derivatives from the Endophytic Fungus Fusarium solani Induce Pancreatic Cancer Cells Apoptosis via Targeting EGFR-Mediated PI3K/Akt Pathway

Seven new polyketide compounds, four naphthoquinone derivatives, neofusarubins A-D (1, 3, 5, and 18) and three graminin-like compounds, fusofuranones A-C (19-21), together with 14 known naphthoquinone derivatives, were isolated from the solid fermentation of Fusarium solani, an endophytic fungus obtained from medicinal plant as tea, Camellia chrysantha. The structures of new compounds were elucidated based on chemical evidence and spectral data analysis (1D and 2D-NMR, HR-ESI-MS, ECD, SC-XRD). Among the isolated compounds tested, 2-acetonyl-3-methyl-5-hydroxy-7-methoxy-naphthazarin (11) exhibited the most potent inhibitory activity against pancreatic cancer in PANC-1, MiaPaCa-2, and BxPC-3 cells. Network pharmacology analysis revealed that compound 11 inhibited cell proliferation and promotion of apoptosis by targeting epidermal growth factor receptor (EGFR), which were confirmed by cellular thermal shift assay (CETSA), microscale thermophoresis (MST) and EGFR stably knockdown cells model assay, respectively. In addition, molecular mechanism studies in vitro showed that 11 could suppress the growth of pancreatic cancer cells by targeting EGFR and effectively inhibit downstream PI3K/Akt signaling pathway. Collectively, these findings provide a new EGFR targeting natural product for the treatment of pancreatic cancer.

Ancestral Sequence Reconstruction to Enable Biocatalytic Synthesis of Azaphilones

Biocatalysis can be powerful in organic synthesis but is often limited by enzymes' substrate scope and selectivity. Developing a biocatalytic step involves identifying an initial enzyme for the target reaction followed by optimization through rational design, directed evolution, or both. These steps are time consuming, resource-intensive, and require expertise beyond typical organic chemistry. Thus, an effective strategy for streamlining the process from enzyme identification to implementation is essential to expanding biocatalysis. Here, we present a strategy combining bioinformatics-guided enzyme mining and ancestral sequence reconstruction (ASR) to resurrect enzymes for biocatalytic synthesis. Specifically, we achieve an enantioselective synthesis of azaphilone natural products using two ancestral enzymes: a flavin-dependent monooxygenase (FDMO) for stereodivergent oxidative dearomatization and a substrate-selective acyltransferase (AT) for the acylation of the enzymatically installed hydroxyl group. This cascade, stereocomplementary to established chemoenzymatic routes, expands access to enantiomeric linear tricyclic azaphilones. By leveraging the co-occurrence and coevolution of FDMO and AT in azaphilone biosynthetic pathways, we identified an AT candidate, CazE, and addressed its low solubility and stability through ASR, obtaining a more soluble, stable, promiscuous, and reactive ancestral AT (AncAT). Sequence analysis revealed AncAT as a chimeric composition of its descendants with enhanced reactivity likely due to ancestral promiscuity. Flexible receptor docking and molecular dynamics simulations showed that the most reactive AncAT promotes a reactive geometry between substrates. We anticipate that our bioinformatics-guided, ASR-based approach can be broadly applied in target-oriented synthesis, reducing the time required to develop biocatalytic steps and efficiently access superior biocatalysts.

Isochromophilones H-K, the new bioactive azaphilone derivatives isolated from fungal strain Diaporthe perseae associated with Pongamia pinnata plant

The phytochemical study of the Diaporthe species has revealed significant classes of mycotoxins and phomopsins. Dihydroanthracenone derivatives, chromanones and isochromophilones have also been isolated from Diaporthe sp. These findings led us to explore the Diaporthe perseae for phytochemical analysis that resulted in the isolation of four new compounds designated as isochromophilones H-K (1-4), alongside three previously identified metabolites. Using extensive spectroscopic investigations such as NMR, and Mass spectroscopy, their structures were elucidated. Furthermore, the antimicrobial and anti-diabetic potentials of all isolated compounds were assessed. Compounds 1-3 demonstrated significant antibacterial activity, while compounds 4-7 exhibited comparatively lower effectiveness than the reference antibiotics. Compounds 2-3 showed potent diabetic inhibition, displaying IC50 values of 16.3 ± 0.3 and 25.4 ± 0.3, respectively. Compounds 1, 5, and 6 displayed mild anti-diabetic effects, with IC50 values of 56.5 ± 0.8, 37.6 ± 0.4, and 48.2 ± 0.6. However, compounds 4 and 7 were found least active.

1O2 and Base Assisted Oxidative Conversion of β-Enaminoesters to α-Acyloxy-β-ketoesters under Visible Light Irradiation

Singlet oxygen (1O2) and base assisted conversion of β-enaminoesters to α-acyloxy-β-ketoesters is demonstrated under visible light irradiation. The reaction involves formation of an imine intermediate via ene-type pathway initiated by 1O2 followed by base promoted dimerization and hydrolysis steps. The method is mild, environmentally friendly, requires air as the oxidant, and gives the products in moderate to high yields.

Evaluation of Phenazine Derivatives from the Lichen-Associated Streptomyces flavidovirens as Potent Antineuroinflammatory Agents In Vitro and In Vivo

Eighteen nitrogen-containing compounds (1-18) were isolated from cultures of the lichen-associated Streptomyces flavidovirens collected from the Qinghai-Tibet Plateau, including seven phenazine derivatives with three new ones, named subphenazines A-C (2-4), two new furan pyrrolidones (8-9), and nine known alkaloids. The structures were elucidated by spectroscopic data analysis, and absolute configurations were determined by single-crystal X-ray diffraction and ECD calculations. The phenazine-type derivatives, in particular compound 3, exhibited significantly better antineuroinflammatory activity than other isolated compounds (8-18). Compound 3 inhibited the release of proinflammatory cytokines including IL-6, TNF-α, and PGE2, and the nuclear translocation of NF-κB; it also reduced the oxidative stress and activated the Nrf2 signaling pathway in LPS-induced BV2 microglia cells. In vivo anti-inflammatory activity in zebrafish indicated that 3 inhibited LPS-stimulated ROS generation. These findings suggested that compound 3 might be a potent antineuroinflammatory agent through the regulation of the NF-κB/Nrf2 signaling pathways.

Crystal structure and characterization of monascin from the extracts of Monascus purpureus-fermented rice

We present a novel solid form of monascin, an azaphilonoid derivative extracted from Monascus purpureus-fermented rice. The crystal structure, C21H26O5, was characterized by single-crystal X-ray diffraction and belongs to the orthorhombic space group P212121. To gain insight into the electronic properties of the short contacts in the crystalline state of monascin, we utilized the Experimental Library of Multipolar Atom Model 2 (ELMAM2) database to transfer the electron density of monascin in its crystalline state. Hirshfeld surface analysis, fingerprint analysis, electronic properties and energetic characterization reveal that intermolecular C-H...O hydrogen bonds play a crucial role in the noncovalent bonding interactions by connecting molecules into two- and three-dimensional networks. The molecular electrostatic potential (MEP) map of the monascin molecule demonstrates that negatively charged regions located at four O atoms are favoured binding sites for more positively charged amino acid residues during molecular recognition. In addition, powder X-ray diffraction confirms that no transformation occurs during the crystallization of monascin.

Baeyer-Villiger oxidation: a promising tool for the synthesis of natural products: a review

Baeyer-Villiger oxidation is a well-known reaction utilized for the synthesis of lactones and ester functionalities from ketones. Chiral lactones can be synthesized from chiral or racemic ketones by employing asymmetric Baeyer-Villiger oxidation. These lactones act as key intermediates in the synthesis of most of the biologically active natural products, their analogues, and derivatives. Various monooxygenases and oxidizing agents facilitate BV oxidation, providing a broad range of synthetic applications in organic chemistry. The variety of enzymatic and chemoselective Baeyer-Villiger oxidations and their substantial role in the synthesis of natural products i.e., alkaloids, polyketides, fatty acids, terpenoids, etc. (reported since 2018) have been summarized in this review article.

Activation of a Silent Gene Cluster from the Endophytic Fungus Talaromyces sp. Unearths Cryptic Azaphilone Metabolites

Fungal azaphilones have attracted widespread attention due to their significant potential as sources of food pigments and pharmaceuticals. Genome mining and gene cluster activation represent powerful tools and strategies for discovering novel natural products and bioactive molecules. Here, a putative azaphilone biosynthetic gene cluster lut from the endophytic fungus Talaromyces sp. was identified through genome mining. By overexpressing the pathway-specific transcription factor LutB, five new sclerotiorin-type azaphilones (1, 6, 8, and 10-11) together with seven known analogues (2-5, 7, 9, 12) were successfully produced. Compounds 8 and 9 exhibited antibacterial activity against Bacillus subtilis with MIC values of 64 and 16 μg/mL, respectively. Compound 11 showed cytotoxic activity against HCT116 and GES-1 with IC50 values of 10.9 and 4.9 μM, respectively, while 1, 4, 5, and 7-10 showed no obvious cytotoxic activity. Gene inactivation experiments confirmed the role of the lut cluster in the production of compounds 1-12. Subsequent feeding experiments unveiled the novel functional diversity of the dual megasynthase system. Furthermore, a LutC-LutD binary oxidoreductase system was discovered, and in combination with DFT calculations, the basic biosynthetic pathway of the sclerotiorin-type azaphilones was characterized. This study provided a good example for the discovery of new azaphilones and further uncovered the biosynthesis of these compounds.

Scalable Total Synthesis of Acremolactone B

Acremolactone B is a pyridine-containing azaphilone-type polyketide. The first total synthesis of this molecule was achieved on a gram scale, based on an aza-6π electrocyclization-aromatization strategy for construction of the tetra-substituted pyridine ring. A bicyclic intermediate was expeditiously prepared by using [2+2] photocycloaddition and chemoselective Baeyer-Villiger oxidation, which was further elaborated to a densely substituted aza-triene. An electrocyclization-aromatization cascade was utilized to forge the tetracyclic core of this natural product, and the side chain was introduced through diastereoselective acylation and reduction.

Azaphilone pigments from the marine-derived Penicillium sclerotium UJNMF 0503 and their neuroprotective potential against H2O2-induced cell apoptosis through modulating PI3K/Akt pathway

Azaphilones represent a particular group of fascinating pigments from fungal source, with easier industrialization and lower cost than the traditional plant-derived pigments, and they also display a wide range of pharmacological activities. Herein, 28 azaphilone analogs, including 12 new ones, were obtained from the fermentation culture of a marine fungus Penicillium sclerotium UJNMF 0503. Their structures were elucidated by MS, NMR and ECD analyses, together with NMR and ECD calculations and biogenetic considerations. Among them, compounds 1 and 2 feature an unusual natural benzo[d][1,3]dioxepine ring embedded with an orthoformate unit, while 3 and 4 represent the first azaphilone examples incorporating a novel rearranged 5/6 bicyclic core and a tetrahydropyran ring on the side chain, respectively. Our bioassays revealed that half of the isolates exhibited neuroprotective potential against H2O2-induced injury on RSC96 cells, while compound 13 displayed the best rescuing capacity toward the cell viability by blocking cellular apoptosis, which was likely achieved by upregulating the PI3K/Akt signaling pathway.

Neuroprotective azaphilones from a deep-sea derived fungus Penicillium sp. SCSIO41030

Ten azaphilones including one pair of new epimers and three new ones, penineulones A-E (1-5) with the same structural core of angular deflectin, were obtained from a deep-sea derived Penicillium sp. SCSIO41030 fermented on a liquid medium. Their structures including absolute configurations were elucidated using chiral-phase HPLC analysis, extensive NMR spectroscopic and HRESIMS data, ECD and NMR calculations, and by comparing NMR data with literature data. Biological assays showed that the azaphilones possessed no antitumor and anti-viral (HSV-1/2) activities at concentrations of 5.0 μM and 20 μM, respectively. In addition, azaphilones 8 and 9 showed neuroprotective effects against Aβ25-35-induced neurotoxicity in primary cultured cortical neurons at a concentration of 10 μM. Azaphilones 8 and 9 dramatically promoted axonal regrowth against Aβ25-35-induced axonal atrophy. Our study indicated that azaphilones could be promising lead compounds for neuroprotection.

Natural Product-Derived Phytochemicals for Influenza A Virus (H1N1) Prevention and Treatment

Influenza A (H1N1) viruses are prone to antigenic mutations and are more variable than other influenza viruses. Therefore, they have caused continuous harm to human public health since the pandemic in 2009 and in recent times. Influenza A (H1N1) can be prevented and treated in various ways, such as direct inhibition of the virus and regulation of human immunity. Among antiviral drugs, the use of natural products in treating influenza has a long history, and natural medicine has been widely considered the focus of development programs for new, safe anti-influenza drugs. In this paper, we focus on influenza A (H1N1) and summarize the natural product-derived phytochemicals for influenza A virus (H1N1) prevention and treatment, including marine natural products, flavonoids, alkaloids, terpenoids and their derivatives, phenols and their derivatives, polysaccharides, and derivatives of natural products for prevention and treatment of influenza A (H1N1) virus. We further discuss the toxicity and antiviral mechanism against influenza A (H1N1) as well as the druggability of natural products. We hope that this review will facilitate the study of the role of natural products against influenza A (H1N1) activity and provide a promising alternative for further anti-influenza A drug development.

Penifuranone A: A Novel Alkaloid from the Mangrove Endophytic Fungus Penicillium crustosum SCNU-F0006

One previously undescribed alkaloid, named penifuranone A (1), and three known compounds (2-4) were isolated from the mangrove endophytic fungus Penicillium crustosum SCNU-F0006. The structure of the new alkaloid (1) was elucidated based on extensive spectroscopic data analysis and single-crystal X-ray diffraction analysis. Four natural isolates and one new synthetic derivative of penifuranone A, compound 1a, were screened for their antimicrobial, antioxidant, and anti-inflammatory activities. Bioassays revealed that penifuranone A (1) exhibited strong anti-inflammatory activity in vitro by inhibiting nitric oxide (NO) production in lipopolysaccharide-activated RAW264.7 cells with an IC50 value of 42.2 μM. The docking study revealed that compound 1 exhibited an ideal fit within the active site of the murine inducible nitric oxide synthase (iNOS), establishing characteristic hydrogen bonds.

Comprehensive Analysis of Penicillium Sclerotiorum: Biology, Secondary Metabolites, and Bioactive Compound Potential─A Review

The filamentous fungus Penicillium sclerotiorum is significant in ecological and industrial domains due to its vast supply of secondary metabolites that have a diverse array of biological functions. We have gathered the metabolic potential and biological activities associated with P. sclerotiorum metabolites of various structures, based on extensive research of the latest literature. The review incorporated literature spanning from 2000 to 2023, drawing from reputable databases including Google Scholar, ScienceDirect, Scopus, and PubMed, among others. Ranging from azaphilones, meroterpenoids, polyketides, and peptides group exhibits fascinating potential pharmacological activities such as antimicrobial, anti-inflammatory, and antitumor effects, holding promise in pharmaceutical and industrial sectors. Additionally, P. sclerotiorum showcases biotechnological potential through the production of enzymes like β-xylosidases, β-d-glucosidase, and xylanases, pivotal in various industrial processes. This review underscores the need for further exploration into its genetic foundations and cultivation conditions to optimize the yield of valuable compounds and enzymes, highlighting the unexplored potential of P. sclerotiorum in diverse applications across industries.

Unveiling the fungal color palette: pigment analysis of Fusarium solani species complex and Curvularia verruculosa clinical isolates

Fungal species in the Nectriaceae, such as Fusarium spp. (Hypocreales: Nectriaceae), are etiologic agents of hyalohyphomycosis capable of producing violaceous or yellowish pigments under certain conditions, while Curvularia spp. (Pleosporales: Pleosporaceae) are agents of phaeohyphomycosis and typically produce melanin in their cell walls. In nectriaceous and pleosporaceous fungi, these pigments are mainly constituted by polyketides (e.g., azaphilones, naphthoquinones, and hydroxyanthraquinones). Considering the importance of pigments synthesized by these genera, this work focused on the selective extraction of pigments produced by eight Fusarium solani species complex and one Curvularia verruculosa isolate recovered from dermatomycosis specimens, their separation, purification, and posterior chemical analysis. The pigments were characterized through spectral and acid-base analysis, and their maximum production time was determined. Moreover, spectral identification of isolates was carried out to approach the taxonomic specificity of pigment production. Herein we describe the isolation and characterization of three acidic pigments, yellowish and pinkish azaphilones (i.e., coaherin A and sclerotiorin), and a purplish xanthone, reported for the first time in the Nectriaceae and Pleosporaceae, which appear to be synthesized in a species-independent manner, in the case of fusaria.

Substrate-Selective Catalysis Enabled Synthesis of Azaphilone Natural Products

Achieving substrate-selectivity is a central element of nature's approach to synthesis. By relying on the ability of a catalyst to discriminate between components in a mixture, control can be exerted over which molecules will move forward in a synthesis. This approach can be powerful when realized but can be challenging to duplicate in the laboratory. In this work, substrate-selective catalysis is leveraged to discriminate between two intermediates that exist in equilibrium, subsequently directing the final cyclization to arrive at either the linear or angular tricyclic core common to subsets of azaphilone natural products. By using a flavin-dependent monooxygenase (FDMO) in sequence with an acyl transferase (AT), the conversion of several orcinaldehyde substrates directly to the corresponding linear tricyclic azaphilones in a single reaction vessel was achieved. Further, mechanistic studies support that a substrate equilibrium together with enzyme substrate selectivity play an import role in the selectivity of the final cyclization step. Using this strategy, five azaphilone natural products were synthesized for the first time as well as a number of unnatural derivatives thereof.

Morphological and phylogenetic analyses reveal two new Penicillium species isolated from the ancient Great Wall loess in Beijing, China

Introduction

Penicillium species exhibit a broad distribution in nature and play a crucial role in human and ecological environments.

Methods

Two Penicillium species isolated from the ancient Great Wall loess in the Mentougou District of Beijing, China, were identified and described as new species, namely, Penicillium acidogenicum and P. floccosum, based on morphological characteristics and phylogenetic analyses of multiple genes including ITS, BenA, CaM, and RPB2 genes.

Results

Phylogenetic analyses showed that both novel species formed a distinctive lineage and that they were most closely related to P. chrzaszczii and P. osmophilum, respectively.

Discussion

Penicillium acidogenicum is characterized by biverticillate conidiophores that produce globose conidia and is distinguished from similar species by its capacity to grow on CYA at 30°C. Penicillium floccosum is typically recognized by its restricted growth and floccose colony texture. The description of these two new species provided additional knowledge and new insights into the ecology and distribution of Penicillium.

Isolation and Characterization of Antimicrobial Metabolites from the Sophora tonkinensis-Associated Fungus Penicillium sp. GDGJ-N37

Chemical investigation of Penicillium sp. GDGJ-N37, a Sophora tonkinensis-associated fungus, yielded two new azaphilone derivatives, N-isoamylsclerotiorinamine (1) and 7-methoxyl-N-isoamylsclerotiorinamine (2), and four known azaphilones (3-6), together with two new chromone derivatives, penithochromones X and Y (7 and 8). Their structures were elucidated based on spectroscopic data, CD spectrum, and semi-synthesis. Sclerotioramine (3) showed significant antibacterial activities against B. subtilis and S. dysentery, and it also showed most potent anti-plant pathogenic fungi activities against P. theae, C. miyabeanus, and E. turcicum.

Secondary Metabolites of Biscogniauxia: Distribution, Chemical Diversity, Bioactivity, and Implications of the Occurrence

The genus Biscogniauxia, a member of the family Xylariaceae, is distributed worldwide with more than 50 recognized taxa. Biscogniauxia species is known as a plant pathogen, typically acting as a parasite on tree bark, although certain members of this genus also function as endophytic microorganisms. Biscogniauxia endophytic strain has received attention in many cases, which includes constituent research leading to the discovery of various bioactive secondary metabolites. Currently, there are a total of 115 chemical compounds belonging to the class of secondary metabolites, and among these compounds, fatty acids have been identified. In addition, the strong pharmacological agents of this genus are (3aS,4aR,8aS,9aR)-3a-hydroxy-8a-methyl-3,5-dimethylenedecahydronaphto [2,3-b]furan-2(3H)-one (HDFO) (antifungal), biscopyran (phytotoxic activity), reticulol (antioxidant), biscogniazaphilone A and B (antimycobacterial), and biscogniauxone (Enzyme GSK3 inhibitor). This comprehensive research contributes significantly to the potential discovery of novel drugs produced by Biscogniauxia and holds promise for future development. Importantly, it represents the first-ever review of natural products originating from the Biscogniauxia genus.

Novel chlorinated and nitrogenated azaphilones with cytotoxic activities from the marine algal-derived fungus Chaetomium globosum 2020HZ23

Two novel chlorinated and nitrogenated azaphilones, namely N-butyl-2-aza-2-deoxychaetoviridin A (1) and N-hexyl-2-aza-2-deoxychaetoviridin A (2), along with a previously identified analogue, chaetoviridin A (3), were successfully obtained from Chaetomium globosum 2020HZ23, a marine algal-sourced endophytic fungus. The planar structures as well as the absolute configurations of these new metabolites were determined utilizing a synergistic approach that involved both spectroscopic techniques (1D/2D NMR and HRESIMS) and Density Functional Theory (DFT) calculations. Each compound was subject to in vitro cytotoxicity evaluation toward the A549 cancer cell line. Both compounds 1 and 2 demonstrated significant cytotoxicity, as evidenced by their respective IC50 values of 13.6 and 17.5 μM. Furthermore, 1 and 2 demonstrated potent cell migration inhibition, which elevated with increasing dose concentration. In contrast, compound 3 exhibited less cytotoxic activity relative to 1 and 2, suggesting that the cytotoxic potency escalates with N-substitution at the C-2 position and the introduction of a side chain. This finding could offer implications for future studies aimed at designing and refining lead compounds within this class.

Inhibitory Effects of the Fungal Pigment Rubiginosin C on Hyphal and Biofilm Formation in Candida albicans and Candida auris

The two fungal human pathogens, Candida auris and Candida albicans, possess a variety of virulence mechanisms. Among them are the formation of biofilms to protect yeast against harsh conditions through the development of (pseudo)hyphae whilst also facilitating the invasion of host tissues. In recent years, increased rates of antifungal resistance have been associated with C. albicans and C. auris, posing a significant challenge for the effective treatment of fungal infections. In the course of our ongoing search for novel anti-infectives, six selected azaphilones were tested for their cytotoxicity and antimicrobial effects as well as for their inhibitory activity against biofilm and hyphal formation. This study revealed that rubiginosin C, derived from stromata of the ascomycete Hypoxylon rubiginosum, effectively inhibited the formation of biofilms, pseudohyphae, and hyphae in both C. auris and C. albicans without lethal effects. Crystal violet staining assays were utilized to assess the inhibition of biofilm formation, while complementary microscopic techniques, such as confocal laser scanning microscopy, scanning electron microscopy, and optical microscopy, were used to investigate the underlying mechanisms. Rubiginosin C is one of the few substances known to effectively target both biofilm formation and the yeast-to-hyphae transition of C. albicans and C. auris within a concentration range not affecting host cells, making it a promising candidate for therapeutic intervention in the future.

Chemoselective cycloisomerization of O-alkenylbenzamides via concomitant 1,2-aryl migration/elimination mediated by hypervalent iodine reagents

As an ambident nucleophile, controlling the reaction selectivities of nitrogen and oxygen atoms in amide moiety is a challenging issue in organic synthesis. Herein, we present a chemodivergent cycloisomerization approach to construct isoquinolinone and iminoisocoumarin skeletons from o-alkenylbenzamide derivatives. The chemo-controllable strategy employed an exclusive 1,2-aryl migration/elimination cascade, enabled by different hypervalent iodine species generated in situ from the reaction of iodosobenzene (PhIO) with MeOH or 2,4,6-tris-isopropylbenzene sulfonic acid. DFT studies revealed that the nitrogen and oxygen atoms of the intermediates in the two reaction systems have different nucleophilicities and thus produce the selectivity of N or O-attack modes.

Asymmetric Total Synthesis of Chaetoglobin A

An asymmetric total synthesis of chaetoglobin A was achieved. Atroposelective oxidative coupling of a phenol incorporating all but one carbon of the final product was used as a key step to generate axial chirality. The stereochemical outcome of the catalytic oxidative phenolic with the highly substituted phenol used herein was found to be opposite that of the simpler congeners reported previously, providing a cautionary tale about extrapolating asymmetric processes from simple to more complex substrates. Optimization of the postphenolic coupling steps including formylation, oxidative dearomatization, and selective deprotection steps are outlined. The tertiary acetates of chaetoglobin A were exceptionally labile due to activation by the adjacent keto groups, which complicated each of these steps. In contrast, the final oxygen to nitrogen exchange proceeded readily and the spectroscopic data from the synthetic material matches that of the isolated natural product in all respects.

Aniline-induced production of aniline-containing polyketides and related bicyclic polyketides by the Yellow River wetland-derived fungus Talaromyces funiculosus

Introduction and Methods

Silencing gene activation can effectively enrich the diversity of fungal secondary metabolites.

Results and Discussion

Cultivation of the Yellow River wetland-derived fungus Talaromyces funiculosus HPU-Y01 with aniline led to the isolation of one new aniline-containing polyketide tanicutone A (1), two new bicyclic polyketides tanicutones B-C (2-3), a new related trienoic acid 8-methyldeca-2,4,6-trienoic acid (5), and a known compound 4. The planar structures and configurations of 1-5 were determined by NMR, MS, and ECD calculations. Compound 2 featured a key aldehyde group and showed promising inhibitory activity against Vibrio parahaemolyticus with a minimum inhibitory concentration (MIC) value of 0.17 μg/mL. This is a rare report of aniline-induced fungal production of tetrahydronaphthone polyketides.

Terminal carboxylation of branched carbon chain contributing to acidic stability of azaphilone pigments from a new isolate of Talaromyces amestolkiae

Red Monascus pigments, a series of natural azaphilone alkaloids, have been utilized in China as a traditional food colorant for over 1000 years. However, instability under an acidic condition is its drawback. A new strain of Talaromyces amestolkiae was isolated in the present work, which produced the azaphilone talaromycorubrin and the corresponding azaphilone alkaloid (N-MSG-talaromycorubramine) exhibiting good stability even at pH below 3. The azaphilone alkaloid with acidic stability, an alternative of Chinese traditional red Monascus pigments, is potential for application as natural food colorant in acidic foods. The acidic stability of azaphilone alkaloid also benefits for direct fermentation of N-MSG-talaromycorubramine under a low pH condition. More importantly, correlation relationship between the terminal carboxylation of branched carbon chain of azaphilone and the stability of azaphilone alkaloids under an acidic condition is set up for the first time, which makes designing other acidic stable azaphilone alkaloids via genetic engineering become possible.

Deciphering the evolution of flavin-dependent monooxygenase stereoselectivity using ancestral sequence reconstruction

Controlling the selectivity of a reaction is critical for target-oriented synthesis. Accessing complementary selectivity profiles enables divergent synthetic strategies, but is challenging to achieve in biocatalytic reactions given enzymes' innate preferences of a single selectivity. Thus, it is critical to understand the structural features that control selectivity in biocatalytic reactions to achieve tunable selectivity. Here, we investigate the structural features that control the stereoselectivity in an oxidative dearomatization reaction that is key to making azaphilone natural products. Crystal structures of enantiocomplementary biocatalysts guided the development of multiple hypotheses centered on the structural features that control the stereochemical outcome of the reaction; however, in many cases, direct substitutions of active site residues in natural proteins led to inactive enzymes. Ancestral sequence reconstruction (ASR) and resurrection were employed as an alternative strategy to probe the impact of each residue on the stereochemical outcome of the dearomatization reaction. These studies suggest that two mechanisms are active in controlling the stereochemical outcome of the oxidative dearomatization reaction: one involving multiple active site residues in AzaH and the other dominated by a single Phe to Tyr switch in TropB and AfoD. Moreover, this study suggests that the flavin-dependent monooxygenases (FDMOs) adopt simple and flexible strategies to control stereoselectivity, which has led to stereocomplementary azaphilone natural products produced by fungi. This paradigm of combining ASR and resurrection with mutational and computational studies showcases sets of tools for understanding enzyme mechanisms and provides a solid foundation for future protein engineering efforts.

Penazaphilones J–L, Three New Hydrophilic Azaphilone Pigments from Penicillium sclerotiorum cib-411 and Their Anti-Inflammatory Activity

Penazaphilones J–L (1–3), three new hydrophilic azaphilone pigments, as well as six known compounds, were discovered from the filamentous fungus Penicillium sclerotiorum cib-411. Compounds 1–3 were structurally elucidated by the detailed interpretation of their 1D and 2D NMR spectroscopic data. Compound 1 is an unprecedented hybrid of an azaphilone and a glycerophosphate choline. Compounds 2 and 3 each contain an intact amino acid moiety. The bioassay showed that compound 3 exhibited significant anti-inflammatory activity. Concretely, compound 3 significantly suppressed the NO production, the expression levels of COX-2, IL-6, IL-1β, and iNOS mRNA in LPS-stimulated RAW264.7 cells. Moreover, treatment of compound 3 prevented the translocation of NF-κB through inhibiting the phosphorylation of PI3K, PDK1, Akt, and GSK-3β. Thus, the inhibition of compound 3 against LPS-induced inflammation should rely on its inactivation on NF-κB.

Antimicrobial polyketides and sesquiterpene lactones from the deep-sea cold-seep-derived fungus Talaromyces minioluteus CS-113 triggered by the histone deacetylase inhibitor SAHA

Seven new highly oxygenated natural products with diverse chemical structural types, including three new glucosidic polyketides, talaminiosides A-C (1-3), a pair of racemic aromatic polyketides, (±)-talaminone A (4a and 4b), two new azaphilone polyketides, (+)-5-chloromitorubrinic acid (5) and 7-epi-purpurquinone C (7), and one new drimane sesquiterpene lactone, 11-hydroxyminioluteumide B (8), together with a pinazaphilone B sodium salt (6) and 10 known compounds (9-18), were isolated and identified from the culture extract of Talaromyces minioluteus CS-113, a fungus obtained from deep-sea cold-seep sediments collected from the South China Sea. LCMS results indicated that compounds 3 and 4 might be produced by the real activation of silent BGCs triggered by the histone deacetylase inhibitor SAHA, and some of the other compounds were enhanced minor components. Their structures were elucidated by the detailed interpretation of NMR spectroscopic and mass spectrometric data, X-ray crystallographic analysis, ECD and specific rotation (SR) calculations, and DP4+ probability analysis. Compound 7, an azaphilone derivative, exhibited potent activities against several agricultural pathogenic fungi with MIC values equivalent or comparable to amphotericin B. The structure-activity relationship of the isolated azaphilones is briefly discussed. This is the first report of the chemical diversity study of deep-sea cold-seep-derived fungi triggered by SAHA, providing a useful strategy for the activation of cryptic fungal metabolites from deep-sea-derived fungi.

Spirocitrinols A and B, citrinin derivatives with a spiro[chromane-2,3'-isochromane] skeleton from Penicillium citrinum

Spirocitrinols A (1) and B (2), two new citrinin-derived metabolites possessing a spiro[chromane-2,3'-isochromane] skeleton, were isolated from cultures of Penicillium citrinum. Their structures were elucidated primarily by NMR experiments. The absolute configurations of 1 and 2 were assigned by electronic circular dichroism calculations. Compound 2 is the first naturally occurring trimeric citrinin derivative with a spiro[chromane-2,3'-isochromane] core. Compound 1 showed modest cytotoxicity against A549 human tumor cells.

Overexpression of MrEsa1 accelerated growth, increased ascospores yield, and the polyketide production in Monascus ruber

Esa1 has been proven to be an important histone acetyltransferase involved in the regulation of growth and metabolism. Monascus spp. with nearly 2000 years of edible history in East Asian countries can produce a variety of polyketides. It is unknown whether Esa1 plays a regulatory role in Monascus spp. In this study, we isolated the homology of histone acetyltransferase Esa1 (named MrEsa1) and constructed a mresa1-overexpressed strain. Western blot experiments showed that MrEsa1 hyperacetylated at K4 and K9 of the H3 subunit in Monascus ruber. Overexpression of mresa1 led to the larger colony diameter and increased dry cell mass; meanwhile, the conidia germination rate was significantly accelerated in the mresa1-overexpressed strain before 4 h, and the number of ascospores in the mresa1-overexpressed strain was significantly higher than that in WT. In addition, the Monascus azaphilone pigments (MonAzPs) and citrinin production of the mresa1-overexpressed strain were 1.7 and 2.4 times more than those of WT, respectively. Reverse transcription-quantitative polymerase chain reaction experiment suggested that mrpigB, mrpigH, mrpigJ, and mrpigK, involved in MonAzPs synthesis, and pksCT, mrl3, and mrl7, involved in citrinin synthesis, were upregulated in mresa1-overexpressed strain. This study provides important insights into the effect of MrEsa1 on the developmental process and the production of secondary metabolites in Monascus spp.

Discovery of dual PKS involved in sclerotiorin biosynthesis in Penicillium meliponae using genome mining and gene knockout

Fungi of the genus Penicillium section Sclerotiora have as their main characteristic the presence of orange-pigmented mycelium, which is associated with sclerotiorin, a chlorinated secondary metabolite of the azaphilone subclass of polyketides. Sclerotiorin presents anti-diabetes, antioxidant, anti-inflammatory, anti-Alzheimer, antiviral, and antimicrobial activities, which has always attracted the attention of researchers worldwide. During our ongoing search for azaphilone-producing Amazonian fungi, the strain of Penicillium MMSRG-058 was isolated as an endophyte from the roots of Duguetia stelechantha and showed great capacity for producing sclerotiorin-like metabolites. Using multilocus phylogeny, this strain was identified as Penicillium meliponae. Moreover, based on the genome mining of this strain through the reverse approach, a cluster of putative biosynthetic genes (BGC) responsible for the biosynthesis of sclerotiorin-like metabolites (scl cluster) was identified. The knockout of the sclA (highly reducing PKS) and sclI (non-reducing PKS) genes resulted in mutants with loss of mycelial pigmentation and terminated the biosynthesis of sclerotiorin-like metabolites: geumsanol B, chlorogeumsanol B, 7-deacetylisochromophilone VI, isochromophilone VI, ochrephilone, isorotiorin, and sclerotiorin. Based on these results, a biosynthetic pathway was proposed considering the homology of BGC scl genes with the azaphilone BGCs that have already been functionally characterized.

Isolation and Identification of Novel Antioxidant Polyketides from an Endophytic Fungus Ophiobolus cirsii LZU-1509

Sixteen new polyketides, ophicirsins A-P (1-16), including four novel carbon skeletons (5-9, 14, 15, and 16), were isolated from the extract of an endophytic fungus Ophiobolus cirsii LZU-1509. The unique frameworks of ophicirsin N (14) and O (15) feature a different cyclic ether connected with an aromatic ring system. Ophicirsin P (16) is characterized by the unprecedented heterozygote of a polyketide and an alkaloid. The absolute stereochemistries of those polyketides were characterized via single-crystal X-ray diffraction analysis and the experimental and computational electric circular dichroism spectra comparison. Theoretical reaction pathways in the fermentation to generate different novel skeletons starting from acetyl CoA and malonyl CoA helped to assign their structures. Compounds 1-16 appear almost nontoxic in HepG2 and HT-1080 tumor cells. Their antioxidant effects were further evaluated, and 15 exhibits an excellent protection activity in hydrogen peroxide-stimulated oxidative damage in neuron-like PC12 cells via screening all compounds. Moreover, 15 displays a greater ability to scavenge the 2,2-diphenyl-1-picrylhydrazyl free radicals than resveratrol. Taken together, these findings suggest that the novel polyketides could serve as potential antioxidant agents for neuroprotection.

Nitrogen Enriched Solid-State Cultivation for the Overproduction of Azaphilone Red Pigments by Penicillium sclerotiorum SNB-CN111

Azaphilones are microbial specialized metabolites employed as yellow, orange, red or purple pigments. In particular, yellow azaphilones react spontaneously with functionalized nitrogen groups, leading to red azaphilones. In this study, a new two-step solid-state cultivation process to produce specific red azaphilones pigments was implemented, and their chemical diversity was explored based on liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) and a molecular network. This two-step procedure first implies a cellophane membrane allowing accumulating yellow and orange azaphilones from a Penicillium sclerotiorum SNB-CN111 strain, and second involves the incorporation of the desired functionalized nitrogen by shifting the culture medium. The potential of this solid-state cultivation method was finally demonstrated by overproducing an azaphilone with a propargylamine side chain, representing 16% of the metabolic crude extract mass.

New Azaphilones from the Marine-Derived Fungus Penicillium sclerotiorum E23Y-1A with Their Anti-Inflammatory and Antitumor Activities

Nine new azaphilones, including penicilazaphilones I-N (1, 2 and 6-9), epi-geumsanol D (3) and penidioxolanes C (4) and D (5) were isolated from the culture of the marine-derived fungus Penicillium sclerotiorum E23Y-1A. The structures of the isolates were deduced from extensive spectroscopic data (1D and 2D NMR), high-resolution electrospray ionization mass spectrometry (HRESIMS), and electronic circular dichroism (ECD) calculations. All the azaphilones from P. sclerotiorum E23Y-1A were tested for their anti-inflammatory and antitumor activities. Penicilazaphilone N (9) showed moderate anti-inflammatory activity with an IC₅₀ value of 22.63 ± 2.95 μM, whereas penidioxolane C (4) exhibited moderate inhibition against human myeloid leukemia cells (K562), human liver cancer cells (BEL-7402), human gastric cancer cells (SGC-7901), human non-small cell lung cancer cells (A549), and human hela cervical cancer cells, with IC₅₀ values of 23.94 ± 0.11, 60.66 ± 0.13, 46.17 ± 0.17, 60.16 ± 0.26, and 59.30 ± 0.60 μM, respectively.

Naturally Occurring Organohalogen Compounds-A Comprehensive Review

The present volume is the third in a trilogy that documents naturally occurring organohalogen compounds, bringing the total number-from fewer than 25 in 1968-to approximately 8000 compounds to date. Nearly all of these natural products contain chlorine or bromine, with a few containing iodine and, fewer still, fluorine. Produced by ubiquitous marine (algae, sponges, corals, bryozoa, nudibranchs, fungi, bacteria) and terrestrial organisms (plants, fungi, bacteria, insects, higher animals) and universal abiotic processes (volcanos, forest fires, geothermal events), organohalogens pervade the global ecosystem. Newly identified extraterrestrial sources are also documented. In addition to chemical structures, biological activity, biohalogenation, biodegradation, natural function, and future outlook are presented.

New azaphilones from mangrove endophytic fungus Penicillium sclerotiorin SCNU-F0040

Two new sclerotioramines (1 and 2) and a new natural product of sclerotioramine analog (3), together with seven known compounds have been isolated from the mangrove endophytic fungus Penicillium sclerotiorin SCNU-F0040. Their structures were identified based on the 1 D, 2 D NMR and HRESIM spectra. The absolute configurations of new compounds were deduced by specific rotation data and electronic circular dichroism spectra. All the isolated new compounds were tested on anti-diabetes activity by using a-glucosidase inhibition assay and anti-inflammatory activity by using cyclooxygenase inhibition assay, respectively. Compounds 1 and 2 have a-glucosidase inhibition activity with IC₅₀ values of 102.3 and 217.5 μM. Compound 2 shows a moderate cyclooxygenase-2 inhibitory activity with an IC₅₀ value of 47.8 μM.