Isolation and X-ray structure analysis of citreohybridonol from marine-derived Penicillium atrovenetum

Secondary Metabolites from Marine-Derived Fungus Penicillium rubens BTBU20213035

Two new polyketide derivatives, penirubenones A and B (1 and 2), and two naturally rare amino-bis-tetrahydrofuran derivatives, penirubenamides A and B (3 and 4), together with nine known compounds (5-13) were isolated from the marine-derived fungus Penicillium rubens BTBU20213035. The structures were identified by HRESIMS and 1D and 2D NMR analyses, and their absolute configurations were determined by a comparison of experimental and calculated electronic circular dichroism (ECD) spectroscopy and 13C NMR data. We found that 6 exhibited antibacterial activity against Staphylococcus aureus, with an MIC value of 3.125 μg/mL, and 1 and 2 showed synergistic antifungal activity against Candida albicans at 12.5 and 50 μg/mL with 0.0625 μg/mL rapamycin.

Anti-neuroinflammatory andrastin-type meroterpenoids from the marine-derived fungus Penicillium chrysogenum HNNU w0032

A new andrastin-type meroterpenoid penimerodione A (1), and three known analogues (2-4), were isolated from the culture of a marine-derived fungus Penicillium chrysogenum HNNU w0032 by the guidance of MS/MS-based molecular networking. The planar structure of 1 was established by extensive NMR spectroscopic and HRESIMS analyses, and the absolute configuration was elucidated by a single-crystal X-ray diffraction. Compound 1 showed significant inhibitory effect on NO production in LPS-stimulated BV-2 macrophages with an IC50 value of 5.9 ± 0.3 μM. The Western blot result revealed that compound 1 exerted an anti-neuroinflammatory effect via the MAPK signalling pathway.

New Hydroxyphenylacetic Acids and α-Pyrone Derivative from the Deep-Sea Cold Seep Sediment-Derived Fungus Penicillium corylophilum CS-682

Two pairs of new enantiomeric hydroxyphenylacetic acid derivatives, (±)-corylophenols A and B ((±)-1 and (±)-2), a new α-pyrone analogue, corylopyrone A (3), and six andrastin-type meroterpenoids (4-9) were isolated and identified from the deep-sea cold-seep sediment-derived fungus Penicillium corylophilum CS-682. Their structures and stereo configurations were determined by detailed spectroscopic analysis of NMR and MS data, chiral HPLC analysis, J-based configuration analysis, and quantum chemical calculations of ECD, specific rotation, and NMR (with DP4+ probability analysis). Compound 3 showed inhibitory activity against some strains of pathogenic bacteria.

Peniandrastins A-H: Andrastin-type meroterpenoids with immunosuppressive activity from a Penicillium sp

Eight unreported andrastin-type meroterpenoids, namely peniandrastins A-H (1-8), along with six known analogues (9-14), were isolated from the fermentation of a soil-derived fungus Penicillium sp.sb62. Their structures with absolute configurations were elucidated by detailed analyses of the spectroscopic data and single-crystal X-ray diffraction. Compounds 1-4 belong to a rare class of 21-nor-andrastin meroterpenoids, of which 1 bears a 10-hydroperoxyl group, and 2 and 3 feature a 6/6/6/5/5 and a 6/6/6/5/6 pentacyclic systems, respectively. Compounds 5-8 are C25 andrastin-type meroterpenoids, wherein 5 features an unprecedented cyclopentan-1-keton-3-hemiacetal moiety. Additionally, the absolute configuration of compound 9 was corroborated by single-crystal X-ray crystallography for the first time. All isolates were evaluated for their immunosuppressive activities. As a result, compounds 1, 3, 4, 7-9 and 12-14 inhibited concanavalin A-induced T cell proliferation with IC50 values ranging from 7.49 to 36.52 μM, and 1-4, 6-9 and 12-14 inhibited lipopolysaccharide-induced B cell proliferation with IC50 values ranging from 6.73 to 26.27 μM. The preliminary structure-activity relationships (SARs) of those isolates were also discussed.

Oxandrastins: Antibacterial Meroterpenes from an Australian Mud Dauber Wasp Nest-Associated Fungus, Penicillium sp. CMB-MD14

The ethyl acetate extract of an ISP-2 agar cultivation of the wasp nest-associated fungus Penicillium sp. CMB-MD14 exhibited promising antibacterial activity against vancomycin-resistant enterococci (VRE), with a bioassay guided chemical investigation yielding the new meroterpene, oxandrastin A (1), the first andrastin-like metabolite with an extra oxygenation at C-2. A culture media optimisation strategy informed a scaled-up rice cultivation that yielded 1, together with three new oxandrastins B-D (2-4), two known andrastins C (5) and F (6), and a new meroterpene of the austalide family, isoaustalide F (7). Structures of 1-7 were assigned based on detailed spectroscopic analysis and chemical interconversion. A GNPS molecular networking analysis of the rice cultivation extract detected the known austalides B (8), H (9), and H acid (10), tentatively identified based on molecular formulae and co-clustering with 7. That the anti-VRE properties of the CMB-MD14 extract were exclusively attributed to 1 (IC₅₀ 6.0 µM, MIC₉₉ 13.9 µM), highlights the importance of the 2-OAc and 3-OAc moieties to the oxandrastin anti-VRE pharmacophore.

Marine Sponge-Associated Fungi as Potential Novel Bioactive Natural Product Sources for Drug Discovery: A Review

Marine sponge-associated fungi are promising sources of structurally interesting and bioactive secondary metabolites. Great plenty of natural products have been discovered from spongeassociated fungi in recent years. Here reviewed are 571 new compounds isolated from marine fungi associated with sponges in 2010-2018. These molecules comprised eight different structural classes, including alkaloids, polyketides, terpenoids, meroterpenoids, etc. Moreover, most of these compounds demonstrated profoundly biological activities, such as antimicrobial, antiviral, cytotoxic, etc. This review systematically summarized the structural diversity, biological function, and future potential of these novel bioactive natural products for drug discovery.

New Andrastin-Type Meroterpenoids from the Marine-Derived Fungus Penicillium sp

Three new andrastin-type meroterpenoids penimeroterpenoids A-C (1-3) together with two known analogs (4 and 5) were isolated from the cultures of the marine-derived Penicillium species (sp.). The structures of the new compounds were elucidated on the basis of 1- and 2-dimensional (1D/2D) Nuclear Magnetic Resonance (NMR) spectroscopic and mass spectrometric analysis. The absolute configurations of 1-3 were determined by comparison of experimental and calculated electronic circular dichroism (ECD) spectra. Compound 1 showed moderate cytotoxicity against A549, HCT116, and SW480 cell lines.

Tyrosine and terezine derivatives from the marine-sponge-derived fungus Phoma herbarum YG5839

A new tyrosine derivative (1), and two new terezine derivatives (2 and 3) were discovered from a marine-sponge-derived fungus Phoma herbarum YG5839. Those compounds were identified by comprehensive spectroscopic analysis, and antifungal activities were conducted against Fusarium oxysporum, Fusarium graminearum, Penicillium italicum, Colletotrictum gloeosporioides and Colletotrichum musae.

Marine natural products

This review covers the literature published between January and December in 2018 for marine natural products (MNPs), with 717 citations (706 for the period January to December 2018) referring to compounds isolated from marine microorganisms and phytoplankton, green, brown and red algae, sponges, cnidarians, bryozoans, molluscs, tunicates, echinoderms, mangroves and other intertidal plants and microorganisms. The emphasis is on new compounds (1554 in 469 papers for 2018), together with the relevant biological activities, source organisms and country of origin. Reviews, biosynthetic studies, first syntheses, and syntheses that led to the revision of structures or stereochemistries, have been included. The proportion of MNPs assigned absolute configuration over the last decade is also surveyed.

Discovery of andrastones from the deep-sea-derived Penicillium allii-sativi MCCC 3A00580 by OSMAC strategy

Andrastones are unusual 6,6,6,5-tetracyclic meroterpenoids that are rarely found in nature. Previously, three andrastones were obtained from the rice static fermentation extract of the deep-sea-derived fungus Penicillium allii-sativi MCCC 3A00580. Inspired by one strain many compounds (OSMAC) approach, the oat static fermentation on P. allii-sativi was conducted. As a result, 14 andrastones were isolated by UV-guided isolation. The chemical structures of the nine new compounds (1-9) was established by comprehensive analysis of the NMR, MS, ECD, and X-ray crystallography and the five known ones (10-14) were assigned by comparing their NMR, MS, and OR data with those reported in literature. Compound 1 bears a novel hemiketal moiety while 2 is the first example to possess a novel tetrahydrofuran moiety via C-7 and C-15. All isolates were tested for anti-allergic bioactivity. Compound 10, 3-deacetylcitreohybridonol, significantly decreased degranulation with the IC₅₀ value of 14.8 μM, compared to that of 92.5 μM for the positive control, loratadine. Mechanism study indicated 10 could decrease the generation of histamine and TNF-α by reducing the accumulation of Ca²⁺ in RBL-2H3 cells. These findings indicate andrastones could be potential to discover new anti-allergic candidate drugs.

Three new andrastin derivatives from the endophytic fungus Penicillium vulpinum

Three new andrastin derivatives, 10-formyl andrastone A (1), 10-demethylated andrastone A (2) and andrastin G (3), together with four known andrastin analogues (4-7) were isolated from an endophytic fungus Penicillium vulpinum. Their structures were determined by 1 D, 2 D NMR, and the absolute configurations were further determined by experimental and calculated ECD spectra. Compound 5 exhibited significant antibacterial activity against Bacillus paratyphosus B with an MIC value of 6.25 µg·mL^-1. Compounds 2 and 6 showed remarkable inhibitory activities against Bacillus megaterium with the MIC value of 6.25 µg·mL^-1, respectively.

Meroterpenoids produced by fungi: Occurrence, structural diversity, biological activities, and their molecular targets

Meroterpenoids are partially derived from the terpenoids, distributing widely in the plants, animals and fungi. The complex structures and diverse bioactivities of meroterpenoids have attracted more attention for chemists and pharmacologists. Since the first review summarized by Geris in 2009, there are absent of systematic reviews reported about meroterpenoids from the higher and lower fungi up to now. In the past decades, myriads of meroterpenoids were discovered, and it is necessary to summarize these meroterpenoids about their unique structures and promising bioactivities. In this review, we use a new classification method based on the non-terpene precursors, and also highlight the structural features, bioactivity of natural meroterpenoids from the higher and lower fungi covering the period of September 2008 to February 2020. A total of 709 compounds were discussed and cited the 182 references. Meanwhile, we also primarily summarize their occurrence, structural diversity, biological activities, and molecular targets.

Penicimeroterpenoids A-C, Meroterpenoids with Rearrangement Skeletons from the Marine-Derived Fungus Penicillium sp. SCSIO 41512

Three novel andrastin-type meroterpenoids, penicimeroterpenoids A-C (1-3), possessing two unprecedented skeletons consisting of fused 6/5/6/6/7 and 6/5/6/6/4 polycyclic systems, were obtained from the marine-derived fungus Penicillium sp. SCSIO 41512. Their structures were determined by spectroscopic methods, and the absolute configurations were further determined by single-crystal X-ray diffraction analysis for 1 and quantum chemical calculations of ECD spectra for 2 and 3, respectively. A plausible biosynthetic pathway for 1-3 was proposed.

A Review of Terpenes from Marine-Derived Fungi: 2015-2019

Marine-derived fungi are a significant source of pharmacologically active metabolites with interesting structural properties, especially terpenoids with biological and chemical diversity. In the past five years, there has been a tremendous increase in the rate of new terpenoids from marine-derived fungi being discovered. In this updated review, we examine the chemical structures and bioactive properties of new terpenes from marine-derived fungi, and the biodiversity of these fungi from 2015 to 2019. A total of 140 research papers describing 471 new terpenoids of six groups (monoterpenes, sesquiterpenes, diterpenes, sesterterpenes, triterpenes, and meroterpenes) from 133 marine fungal strains belonging to 34 genera were included. Among them, sesquiterpenes, meroterpenes, and diterpenes comprise the largest proportions of terpenes, and the fungi genera of Penicillium, Aspergillus, and Trichoderma are the dominant producers of terpenoids. The majority of the marine-derived fungi are isolated from live marine matter: marine animals and aquatic plants (including mangrove plants and algae). Moreover, many terpenoids display various bioactivities, including cytotoxicity, antibacterial activity, lethal toxicity, anti-inflammatory activity, enzyme inhibitor activity, etc. In our opinion, the chemical diversity and biological activities of these novel terpenoids will provide medical and chemical researchers with a plenty variety of promising lead compounds for the development of marine drugs.

A Review of Anti-Inflammatory Compounds from Marine Fungi, 2000-2018

Inflammation is a generalized, nonspecific, and beneficial host response of foreign challenge or tissue injury. However, prolonged inflammation is undesirable. It will cause loss function of involve organs, such as heat, pain redness, and swelling. Marine natural products have gained more and more attention due to their unique mechanism of anti-inflammatory action, and have considered a hotspot for anti-inflammatory drug development. Marine-derived fungi are promising sources of structurally unprecedented bioactive natural products. So far, a plethora of new secondary metabolites with anti-inflammatory activities from marine-derived fungi had been widely reported. This review covers 133 fungal metabolites described in the period of 2000 to 2018, including the structures and origins of these secondary metabolites.

Andrastone A From the Deep-Sea-Derived Fungus Penicillium allii-sativi Acts as an Inducer of Caspase and RXRα-Dependent Apoptosis

Two new (1, 2) and one known (3) meroterpenoids were isolated from the deep-sea-derived fungus Penicillium allii-sativi. The relative structures of new compounds were determined on the basis of an extensive analysis of the NMR and MS data, and the absolute configurations were established by ECD calculations. Andrastone A (1) is a rare andrastin bearing an unusual cyclopentan-1,3-dione. It shows a selectively antiproliferative effect against HepG2 tumor cells with an IC50 value of 7.8 μM. Mechanism study showed that apoptosis via Caspase and RXRα pathways are responsible for the inhibitory effect.

Penicamide A, A Unique N,N'-Ketal Quinazolinone Alkaloid from Ascidian-Derived Fungus Penicillium sp. 4829

Previously unreported N,N′-ketal quinazolinone enantiomers [(−)-1 and (+)-1] and a new biogenetically related compound (2), along with six known compounds, 2-pyrovoylaminobenzamide (3), N-(2-hydroxypropanoyl)-2 amino benzoic acid amide (4), pseurotin A (5), niacinamide (6), citreohybridonol (7), citreohybridone C (8) were isolated from the ascidian-derived fungus Penicillium sp. 4829 in wheat solid-substrate medium culture. Their structures were elucidated by a combination of spectroscopic analyses (1D and 2D NMR and Electron Circular Dichroism data) and X-ray crystallography. The enantiomeric pair of 1 is the first example of naturally occurring N,N′-ketal quinazolinone possessing a unique tetracyclic system having 4-quinazolinone fused with tetrahydroisoquinoline moiety. The enantiomeric mixtures of 1 displayed an inhibitory effect on NO production in lipopolysaccharide-activated RAW264.7 cells, while the optically pure (–)-1 showed better inhibitory effect than (+)-1.