Antibacterial Diphenyl Ethers from Fungi Aspergillus versicolor YC-27

Microbial metabolites serve as a vital source for drug discovery, with diphenyl ether derivatives from Aspergillus sp. garnering significant attention due to their antimicrobial activities. This work focused on the antibacterial compounds from the fungi Aspergillus versicolor YC-27, which led to the isolation of one new diphenyl ether derivative, aspesicol (1), together with eight known compounds (2-9). The structure of the new compound was elucidated by spectroscopic methods, high-resolution electrospray ionization mass spectrometry, and nuclear magnetic resonance calculations with DP4+ methods. In the in vitro bioassays, compounds 4, 5, and 9 exhibited good inhibitory activity against Staphylococcus aureus with minimum inhibitory concentration (MIC) values of 8 µg/mL, and compound 6 showed potent inhibitory activity against S. aureus with MIC value of 4 µg/mL. These diphenyl ether derivatives demonstrating significant antimicrobial activity, particularly compound 6, represent highly promising lead candidates for the development of therapeutic agents against multidrug-resistant bacterial infections.

A New Antifungal 3,4-Dimethoxybenzoate Dimer Artefact Formed During Isolation of Aconitum georgei Comber Constituents

A new 3,4-dimethoxybenzoate dimer, georgedimer (1), was obtained from the roots of Aconitum georgei Comber, along with 12 known compounds (2-13) isolated from this species. Their structures were established on the basis of extensive spectroscopic analyses. The results of the antifungal activities indicated that compounds 1, 5, 6, 7, and 8 exhibited antifungal activity against several plant pathogens, including Fusarium solani, F. oxysporum, Plectosphaerella cucumerina, and Alternaria panax, with minimum inhibitory concentration values ranging from 8 to 64 µg/mL.

Five Unreported Ketone Compounds-Penicrustones A-E-From the Endophytic Fungus Penicillium crustosum

Five unreported ketone compounds-penicrustones A-E-were isolated from the solid fermentation of the endophytic fungus Penicillium crustosum. Their structures were elucidated on the basis of extensive spectroscopic analysis. Their absolute configurations were determined via ECD calculations and single-crystal X-Ray crystallography. All compounds were evaluated for their antimicrobial and antitumor activities. Compounds 4 and 5 showed moderate inhibitory effects on Micrococcus luteus, with MIC values of 12.5 and 25.0 μg/mL, respectively. In addition to this, compound 4 also showed cytotoxicity on tumor cell lines KTC-1 and Hela, with IC50 values of 4.28 and 4.64 μg/mL, respectively.

A Paternò-Büchi Reaction of Aromatics with Quinones under Visible Light Irradiation

Reported herein is a Paternò-Büchi reaction of aromatic double bonds with quinones under visible light irradiation. The reactions of aromatics with quinones exposed to blue LED irradiation yielded oxetanes at -78 °C, which was attributed to both the activation of double bonds in aromatics and the stabilization of oxetanes by thiadiazole, oxadiazole, or selenadiazole groups. The addition of Cu(OTf)2 to the reaction system at room temperature resulted in the formation of diaryl ethers via the copper-catalyzed ring opening of oxetanes in situ. Notably, the substrate scope was extended to general aromatics.

A new sesquiterpenoid from the aconitum-derived fungus Aspergillus fumigatus M1

A new bergamotane sesquiterpenoid, fumigatanol (1), along with nine known compounds (2-10) were isolated from the Aconitum-derived fungus Aspergillus fumigatus M1. Their structures were established on the basis of extensive spectroscopic analyses, ECD experiment and NMR computational method. Antibacterial and cytotoxic activities of compound 1 were evaluated and no obvious antibacterial and cytotoxic activities were observed at concentrations of 256 μg/mL and 40.00 μM, respectively.

Bioactive Steroids Bearing Oxirane Ring

This review explores the biological activity and structural diversity of steroids and related isoprenoid lipids, with a particular focus on compounds containing an oxirane ring. These natural compounds are derived from fungi, fungal endophytes, as well as extracts of plants, algae, and marine invertebrates. To evaluate their biological activity, an extensive examination of refereed literature sources was conducted, including in vivo and in vitro studies and the utilization of the QSAR method. Notable properties observed among these compounds include strong anti-inflammatory, antineoplastic, antiproliferative, anti-hypercholesterolemic, antiparkinsonian, diuretic, anti-eczematic, anti-psoriatic, and various other activities. Throughout this review, 3D graphs illustrating the activity of individual steroids are presented, accompanied by images of selected terrestrial or marine organisms. Furthermore, this review provides explanations for specific types of biological activity associated with these compounds. The data presented in this review are of scientific interest to the academic community and carry practical implications in the fields of pharmacology and medicine. By analyzing the biological activity and structural diversity of steroids and related isoprenoid lipids, this review offers valuable insights that contribute to both theoretical understanding and applied research. This review draws upon data from various authors to compile information on the biological activity of natural steroids containing an oxirane ring.

Macrostines A and B: Tetracyclic fisicoccane from the fungus Periconia macrospinosa WTG-10

Two previous unreported fusicoccane diterpenoids macrostines A and B, together with seven known compounds were isolated from an extract of the fungus Periconia macrospinosa WTG-10. Their structures were elucidated by detailed analysis of spectroscopic data, NMR calculations with DP4+, and their absolute configurations were further determined by quantum chemical calculations of ECD spectra or X-crystallography. Macrostines A and B showed no cytotoxicity, antimicrobial activity and inhibitory effect on nitric oxide production in LPS-activated RAW264.7 macrophages. Compound 9 showed moderate activity against Bacillus subtilis.

Polyketides with antimicrobial activities from Penicillium canescens DJJ-1

Two undescribed polyketides canecines A-B, one unreported cyclopentenone canecine C, together with 12 known compounds were isolated from an extract of the fungus Penicillium canescens DJJ-1. Their structures were elucidated by detailed analysis of spectroscopic data, NMR calculations with dJ-DP4 or DP4+, and their absolute configurations were further determined by quantum chemical calculations of ECD spectra or X-crystallography. Canecine A was a grisan polyketide featuring a dimethyltetrahydro-4H-furo[2,3-b]pyran. Canecine A exhibited significant inhibitory activity against Candida albicans with an MIC value of 1 μg/mL and showed inhibitory effect on nitric oxide production in LPS-activated RAW264.7 macrophages. These results enrich the structural diversities of polyketides from endophytic fungi.

A new cycloheptane derivative from the fungus Penicillium crustosum JT-8

A new highly oxygenated cycloheptane derivative crustane (1), along with fourteen known compounds (2-15) were isolated from Penicillium crustosum JT-8. The structure of compound 1 was determined by extensive spectroscopic data, DP4+ probability analyses and dimolybdenum CD method. Compound 1 exhibited moderate antibacterial activity against Staphylococcus aureus with MIC of 4.0 μg/mL.

Investigations of specialised metabolites of endophyte Diaporthe destruens hosted in Illigera orbiculata C. Y. Wu

A chemical investigation of the endophytic fungus Diaporthe destruens from the Hernandiaceae plant Illigera orbiculata C. Y. Wu collected from southern Yunnan Province, China, led to the isolation of six undescribed compounds, including two azaphilone analogs, which are a pair of epimers (13R-hydroxy-chermesinone A and 13S-hydroxy-chermesinone A); a pyrrole derivative (1-(4-(methoxymethyl)-1H-pyrrol-3-yl)ethan-1-one); an isoindolone derivative (4-hydroxy-6-methoxyisoindolin-1-one); a benzylbenzene derivative (destruensine A) and a conjectural fragment of polyketide ((2R,4R)-2-(methoxymethyl)pentane-1,4-diol) along with nine known compounds. Their structures were elucidated by spectroscopic methods and HRESIMS, and the absolute configurations were further confirmed by electronic circular dichroism (ECD) and chemical derivatization. The antimicrobial activities, anti-acetylcholinesterase activities, antiproliferation, and NO production inhibitory effects of compounds 1-15 were evaluated.

Grandiflolines A–F, new anti-inflammatory diterpenoid alkaloids isolated from Delphinium grandiflorum

Delphinium grandiflorum L. (family Ranunculaceae), one of the most important and widely distributed Delphinium species, has received considerable interest due to its extremely high medicinal value. The discovery of novel metabolites from D. grandiflorum supported and broadened its application as an herbal medicine. In this study, the whole herb of D. grandiflorum was phytochemically investigated to obtain fourteen C₁₉-lycaconitine-type diterpenoid alkaloids (1–14), including six undescribed alkaloids, grandiflolines A–F (1–6). The structural elucidation of them was accomplished by detailed spectroscopic analyses, mainly including HR-MS, 1D and 2D NMR (¹H–¹H COSY, NOESY, HMBC and HSQC), and IR spectra. New alkaloids 1–3 and 5 possess a characteristic △^2,3 functional group in the A ring, while compounds 5 and 6 feature a rare OH-16 substituent. In addition, known compounds 7–12 were isolated from D. grandiflorum for the first time. Moreover, according to its medicinal use, new alkaloids 1–6 were estimated for their potential in vitro anti-inflammatory effects, and some of them exhibited inhibitory effects on NO production in LPS-activated RAW 264.7 macrophages. Our work enriched the chemical diversity of D. grandiflorum and the genus Delphinium and presented beneficial information for further investigations.

Bioactive cytochalasans from the fungus Arthrinium arundinis DJ-13

The investigation of the metabolites from Arthrinium arundinis DJ-13 grown in solid medium revealed six undescribed cytochalasans, arundisins A-F and twelve known compounds. Their structures were initially investigated in detail by spectroscopic analyses and were further confirmed by X-crystallography and ECD experiments. In the in vitro bioassays, arundisins A and B showed cytotoxic activity against the MCF-7 breast cancer cell line with IC₅₀ values of 18.82 ± 0.36 and 15.20 ± 0.42 μM, respectively. Arundisin F exhibited potent antibacterial activity against Escherichia coli with MIC of 8.00 μg/mL (kanamycin, 2.00 μg/mL), and arundisin D displayed gently antibacterial activity against Candida albicans with MIC of 32.00 μg/mL (Nystatin, 1.00 μg/mL).

Penaloidines A and B: two unprecedented pyridine alkaloids from Penicillium sp. KYJ-6

Penaloidines A (1) and B (2), a pair of epimers, unprecedented meroterpenoid pyridine alkaloids possessing a tetrahydrofuro[3,2-c][2,7]naphthyridinyl scaffold, were characterized from Penicillium sp. KYJ-6. Their structures were elucidated by spectroscopic...

The chemistry and biology of fungal meroterpenoids (2009-2019)

Fungal meroterpenoids are secondary metabolites from mixed terpene-biosynthetic origins. Their intriguing chemical structural diversification and complexity, potential bioactivities, and pharmacological significance make them attractive targets in natural product chemistry, organic synthesis, and biosynthesis. This review provides a systematic overview of the isolation, chemical structural features, biological activities, and fungal biodiversity of 1585 novel meroterpenoids from 79 genera terrestrial and marine-derived fungi including macrofungi, Basidiomycetes, in 441 research papers in 2009-2019. Based on the nonterpenoid starting moiety in their biosynthesis pathway, meroterpenoids were classified into four categories (polyketide-terpenoid, indole-, shikimate-, and miscellaneous-) with polyketide-terpenoids (mainly tetraketide-) and shikimate-terpenoids as the primary source. Basidiomycota produced 37.5% of meroterpenoids, mostly shikimate-terpenoids. The genera of Ganoderma, Penicillium, Aspergillus, and Stachybotrys are the four dominant producers. Moreover, about 56% of meroterpenoids display various pronounced bioactivities, including cytotoxicity, enzyme inhibition, antibacterial, anti-inflammatory, antiviral, antifungal activities. It's exciting that several meroterpenoids including antroquinonol and 4-acetyl antroquinonol B were developed into phase II clinically used drugs. We assume that the chemical diversity and therapeutic potential of these fungal meroterpenoids will provide biologists and medicinal chemists with a large promising sustainable treasure-trove for drug discovery.

Bioactive sesterterpenoids from the fungus Penicillium roqueforti YJ-14

Seven previously undescribed sesterterpenes were characterized from Penicillium roqueforti YJ-14 by solid fermentation. Their structures were initially investigated in detail by spectroscopic analyses and HR-ESI-MS and were further confirmed by X-crystallography. In in vitro bioassays, compounds 1, 5 and 7 showed cytotoxic activity against the MCF-7 breast cancer cell line with IC₅₀ values of 7.98 ± 0.93, 6.42 ± 0.41 and 7.32 ± 0.18 μM, respectively. Compounds 5 and 7 displayed significant cytotoxicity against the A549 lung cancer cell line (IC₅₀ values of 4.83 ± 0.22 μM and 4.58 ± 0.85 μM, respectively). In addition, compound 5 showed an obvious inhibitory effect on nitric oxide production in LPS-activated RAW264.7 macrophages with an IC₅₀ value of 9.53 ± 0.16 μM.

A new cytotoxic indole alkaloid from the fungus Penicillium polonicum TY12

A new dimeric monoterpene indole alkaloid polonidine A (1), along with five known compounds, cyclopenol (2), verrucosidin (3), fructigenine A (4), 3-O-methylviridicatin (5) and aurantiomides C (6), were isolated from Penicillium polonicum TY12. Their structures were established on the basis of extensive spectroscopic analyses. Compound 1 exhibited moderate cytotoxic activities and moderate antibacterial activity against Bacillus subtilis with MIC of 4.0 μg/mL.

New cytotoxic secondary metabolites against human pancreatic cancer cells from the Hypericum perforatum endophytic fungus Aspergillus terreus

Four new compounds, including two lovastatin analogues, terrstatins A and B (1 and 2), and a pair of butenolide derivatives, (±)-asperteretone F (3a/3b), along with eleven known compounds (4-14), were isolated from the Hypericum perforatum endophytic fungus Aspergillus terreus. Their structures and absolute configurations were determined based on extensive spectroscopic analysis, experimental and calculated electronic circular dichroism (ECD) analysis. All isolates were evaluated for cytotoxic activities against five human cancer cell lines, and compounds 3a/3b and 6 showed potential cytotoxic activities against human pancreatic cancer cells, including AsPC-1, SW1990 and PANC-1 cells, with IC₅₀ values ranging from 1.2 to 15.6 μM.

Roquefornine A, a sesterterpenoid with a 5/6/5/5/6-fused ring system from the fungus Penicillium roqueforti YJ-14

Roquefornine A, a sesterterpenoid with an unprecedented 5/6/5/5/6-membered pentacyclic system, was characterized from Penicillium roqueforti YJ-14.