Hemiacetalmeroterpenoids A-C and Astellolide Q with Antimicrobial Activity from the Marine-Derived Fungus Penicillium sp. N-5

Andrastin-type meroterpenoids, α-pyrone polyketides, and sesquicarane derivatives from Penicillium sp., a fungus isolated from Pinus koraiensis seed

The genus Penicillium has provided us with the household antibiotic penicillin and the well-known lipid-lowering agent mevastatin. The strain Penicillium sp. SZ-1 was found to grow vigorously in an intact Pinus koraiensis seed, it is inferred that the strain may develop unique mechanisms associated with the biosynthesis of rare metabolites. Further fermentation of the strain on solid rice medium yielded thirteen undescribed compounds, including three andrastin-type meroterpenoids (1-3), two α-pyrone polyketides (4 and 5), and eight sesquicarane derivatives (6-13), along with seven known compounds (14-20). Their structures were determined by detailed analysis of the spectroscopic and spectrometric data (NMR and HRESIMS), in addition to comparisons of the experimental and calculated ECD data for absolute configurational assignments. The hemiacetal moiety in compounds 1 and 2 and the 3α-hydroxy group in compound 3 were rarely found in the andrastin-type meroterpenoid family. The sesquicaranes belong to a small group of sesquiterpenoid that are rarely reported. Bioassay study showed that compound 1 exhibited inhibitory effects against Staphylococcus aureus ATCC 29213 and Escherichia coli ATCC 25922 with MIC values of 64 and 32 μg/mL, respectively. In addition, compounds 1 and 3 displayed weak DPPH radical scavenging activities. The andrastins and sesquicaranes in this study enriched the structural diversity of these classes of terpenoids. Of note, this study is the first report on the metabolites of a fungus isolated from P. koraiensis seed.

Antibacterial properties of natural products from marine fungi reported between 2012 and 2023: a review

The oceans are rich in diverse microorganisms, animals, and plants. This vast biological complexity is a major source of unique secondary metabolites. In particular, marine fungi are a promising source of compounds with unique structures and potent antibacterial properties. Over the last decade, substantial progress has been made to identify these valuable antibacterial agents. This review summarizes the chemical structures and antibacterial activities of 223 compounds identified between 2012 and 2023. These compounds, effective against various bacteria including drug-resistant strains such as methicillin-resistant Staphylococcus aureus, exhibit strong potential as antibacterial therapeutics. The review also highlights the relevant challenges in transitioning from drug discovery to product commercialization. Emerging technologies such as metagenomics and synthetic biology are proposed as viable solutions. This paper sets the stage for further research on antibacterial compounds derived from marine fungi and advocates a multidisciplinary approach to combat drug-resistant bacteria.

Novel Bioactive Natural Products from Marine-Derived Penicillium Fungi: A Review (2021-2023)

Marine-derived Penicillium fungi are productive sources of structurally unique and diverse bioactive secondary metabolites, representing a hot topic in natural product research. This review describes structural diversity, bioactivities and statistical research of 452 new natural products from marine-derived Penicillium fungi covering 2021 to 2023. Sediments are the main sources of marine-derived Penicillium fungi for producing nearly 56% new natural products. Polyketides, alkaloids, and terpenoids displayed diverse biological activities and are the major contributors to antibacterial activity, cytotoxicity, anti-inflammatory and enzyme inhibitory capacities. Polyketides had higher proportions of new bioactive compounds in new compounds than other chemical classes. The characteristics of studies in recent years are presented.

Bialorastins A-F, highly oxygenated and polycyclic andrastin-type meroterpenoids with proangiogenic activity from the deep-sea cold-seep-derived fungus Penicillium bialowiezense CS-283

Six new highly oxygenated and polycyclic andrastin-type meroterpenoids, namely, bialorastins A-F (1-6), were discovered from the culture of Penicillium bialowiezense CS-283, a fungus isolated from the deep-sea cold seep squat lobster Shinkaia crosnieri. The planar structures and absolute configurations of these compounds were determined by detailed analysis of spectroscopic data, single crystal X-ray diffraction, and TDDFT-ECD calculations. Structurally, bialorastin A (1) represents a rare 17-nor-andrastin that possesses an unusual 2-oxaspiro[4.5]decane-1,4-dione moiety with a unique 6/6/6/6/5 polycyclic system, while bialorastin B (2) is also a 17-nor-andrastin featuring a gem-propane-1,2-dione moiety. Additionally, bialorastins C-E (3-5) possess a 6/6/6/6/5/5 fused hexacyclic skeleton, characterized by distinctive 3,23-acetal/lactone-bridged functionalities. All isolated compounds were evaluated for their proangiogenic activities in transgenic zebrafish. Compound 3 exhibited significant proangiogenic activity, which notably increased the number and length of intersegmental blood vessels in model zebrafish in a dose-dependent manner at concentrations of 20 and 40 μM. On a molecular scale, the tested compounds were modeled through molecular docking to have insight into the interactions with the possible target VEGFR2. Mechanistically, RT-qPCR results revealed that compound 3 could promote angiogenesis via activating VEGFR2 and subsequently activating the downstream PI3K/AKT and MAPK signaling pathways. These findings indicate that 3 could be a potential lead compound for developing angiogenesis agents.

Recent Updates on the Antimicrobial Compounds from Marine-Derived Penicillium fungi

In this review, 72 compounds isolated from marine-derived Penicillium fungi and their antimicrobial activities are reviewed from 2020 to 2023. According to their structures, these compounds can be divided into terpenoids, polyketides, alkaloids and other structural compounds, among which terpenoids and polyketides are relatively large in number. Some compounds have powerful inhibitory effects against different pathogenic bacteria and fungi. This review aims to provide more useful information and enlightenment for further efficient utilization of Penicillium spp. and their secondary metabolites.

Cyclohexenoneterpenes A-J: Cytotoxic meroterpenoids from mangrove-associated fungus Penicillium sp. N-5

Ten previously undescribed meroterpenoids, cyclohexenoneterpenes A-J (1-7, 18-20), together with 10 known analogues (8-17) were isolated from the mangrove-associated fungus Penicillium sp. N-5. Their structures were elucidated on the basis of extensive spectroscopic and mass spectrometric data. The absolute configurations of the undescribed compounds were assigned by electronic circular dichroism calculations, the modified Mosher's method, NMR calculations and DP4+ analysis. In the bioassay, compounds 10, 11, 15, and 20 exhibited cytotoxicities against SNB-19, MDA-MB-231, MDA-MB-435 and HCT-116 cell lines with IC50 values ranging from 1.4 to 19.1 μM.

ent-Herqueidiketal and epi-Peniciherqueinone Isolated from a Mushroom Derived Fungus Penicillium herquei YNJ-35

A new polyaromatic metabolite, ent-herqueidiketal (1), and a new phenalenone derivative, epi-peniciherqueinone (2), along with twelve known compounds 3-14, were isolated from the fungus Penicillium herquei YNJ-35, a symbiotic fungus of Pulveroboletus brunneopunctatus collected from Nangunhe Nature Reserve, Yunnan Province, China. The structures of 1-14 and the absolute configurations of 1 and 2 were determined by their spectroscopic data or by their single-crystal X-ray diffraction analysis or optical rotation values. Compound 1 showed strong antibacterial activity against Staphylococcus aureus (ATCC 29213) with minimum inhibitory concentration (MIC) of 8 μg/mL. In the cytotoxicity assays, compound 1 showed weak inhibitory activity against breast cancer MCF-7 and mice microglial BV2 cells with half maximal inhibitory concentration (IC50 ) of 17.58 and 29.56 μM; compound 14 showed stronger cytotoxicity against BV2 and MCF-7 cells with IC50 values of 6.57 and 10.26 μM.

Natural products from marine fungi as a source against agricultural pathogenic fungi

There are many kinds of agricultural pathogenic fungi, which may belong to pathogenic fungi in different species, such as Fusarium, Alternaria, Colletotrichum, Phytophthora, and other agricultural pathogens. Pathogenic fungi from different sources are widely distributed in agriculture, which threaten the lives of crops around the world and caused great damage to agricultural production and economic benefits. Due to the particularity of the marine environment, marine-derived fungi could produce natural compounds with unique structures, rich diversities, and significant bioactivities. Since marine natural products with different structural characteristics could inhibit different kinds of agricultural pathogenic fungi, secondary metabolites with antifungal activity could be used as lead compounds against agricultural pathogenic fungi. In order to summarize the structural characteristics of marine natural products against agricultural pathogenic fungi, this review systematically overview the activities against agricultural pathogenic fungi of 198 secondary metabolites from different marine fungal sources. A total of 92 references published from 1998 to 2022 were cited. KEY POINTS: • Pathogenic fungi, which could cause damage to agriculture, were classified. • Structurally diverse antifungal compounds from marine-derived fungi were summarized. • The sources and distributions of these bioactive metabolites were analyzed.

Antioxidative Indenone and Benzophenone Derivatives from the Mangrove-Derived Fungus Cytospora heveae NSHSJ-2

Seven new polyketides, including four indenone derivatives, cytoindenones A–C (1, 3–4), 3′-methoxycytoindenone A (2), a benzophenone derivative, cytorhizophin J (6), and a pair of tetralone enantiomers, (±)-4,6-dihydroxy-5-methoxy-α-tetralone (7), together with a known compound (5) were obtained from the endophytic fungus Cytospora heveae NSHSJ-2 isolated from the fresh stem of the mangrove plant Sonneratia caseolaris. Compound 3 represented the first natural indenone monomer substituted by two benzene moieties at C-2 and C-3. Their structures were determined by the analysis of 1D and 2D NMR, as well as mass spectroscopic data, and the absolute configurations of (±)-7 were determined on the basis of the observed specific rotation value compared with those of the tetralone derivatives previously reported. In bioactivity assays, compounds 1, 4–6 showed potent DPPH· scavenging activities, with EC50 values ranging from 9.5 to 16.6 µM, better than the positive control ascorbic acid (21.9 µM); compounds 2–3 also exhibited DPPH· scavenging activities comparable to ascorbic acid.