Two new compounds from marine-derived fungus Penicillium sp. F11

Cytotoxic Compounds from Marine Fungi: Sources, Structures, and Bioactivity

Marine fungi, such as species from the Penicillium and Aspergillus genera, are prolific producers of a diversity of natural products with cytotoxic properties. These fungi have been successfully isolated and identified from various marine sources, including sponges, coral, algae, mangroves, sediment, and seawater. The cytotoxic compounds derived from marine fungi can be categorized into five distinct classes: polyketides, peptides, terpenoids and sterols, hybrids, and other miscellaneous compounds. Notably, the pre-eminent group among these compounds comprises polyketides, accounting for 307 out of 642 identified compounds. Particularly, within this collection, 23 out of the 642 compounds exhibit remarkable cytotoxic potency, with IC50 values measured at the nanomolar (nM) or nanogram per milliliter (ng/mL) levels. This review elucidates the originating fungal strains, the sources of isolation, chemical structures, and the noteworthy antitumor activity of the 642 novel natural products isolated from marine fungi. The scope of this review encompasses the period from 1991 to 2023.

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.

Asperbenzophenone A and Versicolamide C, New Fungal Metabolites from the Soft Coral Derived Aspergillus sp. SCSIO 41036

Two new compounds, asperbenzophenone A (1) and versicolamide C (5), together with fifteen known compounds were isolated from a soft coral derived fungus Aspergillus sp. SCSIO 41036. Their structures were elucidated by spectroscopic methods, ECD analysis, and by a comparison with data from the literature. In bioassay, compound 8 showed significant inhibitory activity against lipopolysaccharide-inducted nitric oxide (NO) in RAW264.7 cells at the concentration of 10 μM. Additionally, the anti-acetylcholinesterase activity assay showed that 14 exhibited weak inhibition with an IC₅₀ value of 157.8 μM.

Marine natural products as source of new drugs: an updated patent review (July 2018-July 2021)

INTRODUCTION

Marine natural products have aided as rich sources of new bioactive agents. The multiplicity of marine habitations and exclusive ecological conditions of the sea offer mostly unexploited sources of unique biological and chemical entities. In continuation with the authors' previous publication, the present study reviews recently published patents in correlation to the efforts in finding new therapeutically potent chemical and biological entities from marine organisms.

AREAS COVERED

This review summarizes the progress in the field of marine natural products as therapeutic agents based on an analysis of the patents published after June 2018. We have identified 68 unique patent families related to novel marine natural products for this time period. Patent information pertaining to therapeutic applications and clinical studies has been analysed and reported.

EXPERT OPINION

Marine organisms are excellent producers of secondary metabolites with diverse structures and pharmacological activities. Cumulative increase in the number of patents published during the last few years justifies the importance of this study for spotting new entities as sources of therapeutic agents. The new compounds have been claimed to show a range of activities predominantly anticancer, antimicrobial, anti-inflammatory, and neuroprotection. Majority of the recent patents have been filed by Chinese inventors and a number of these patents are still in the prosecution stage.

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.

Two new compounds from a mangrove sediment-derived fungus Penicillium polonicum H175

Two new compounds, 6-acetyl-4-methoxy-3,5-dimethyl-2H-pyran-2-one (1) and (2E,4E)-5-((2S,3S,4R,5R)-3,4-dihydroxy-2,4,5-trimethyltetrahydrofuran-2-yl)-2,4-dimethylpenta-2,4-dienal (2), and 22 known compounds were identified from the mangrove-forest-derived fungus Penicillium polonicum H175. The structures of these compounds were elucidated by analysis of the high-resolution electrospray ionisation mass spectroscopy (HR-ESI-MS), 1 D and 2 D nuclear magnetic resonance (NMR) data. The hypoglycaemic effect of compounds was evaluated by the Tg (Ins: htBidTE-ON; LR) zebrafish model. Compound 3 (aspterric acid) exhibited a significant hypoglycaemic effect equivalent to the positive drug rosiglitazone (RSG) at 10 μmol/L.

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.

Two New Cytotoxic Compounds from a Deep-Sea Penicillum citreonigrum XT20-134

Penicillum citreonigrum XT20-134 (MCCC 3A00956) is a fungus with cytotoxic activity, derived from deep-sea sediment. Five new compounds, adeninylpyrenocine (1), 2-hydroxyl-3-pyrenocine-thio propanoic acid (2), ozazino-cyclo-(2,3-dihydroxyl-trp-tyr) (3), 5,5-dichloro-1-(3,5-dimethoxyphenyl)-1,4-dihydroxypentan-2-one (4), and 2,3,4-trihydroxybutyl cinnamate (5), together with 19 known compounds (6-24), were isolated from an ethyl acetate (EtOAc) extract of its fermentation. The structures of the new compounds were comprehensively characterized by high-resolution electrospray ionization-mass spectrometry (HR-ESI-MS), 1D and 2D nuclear magnetic resonance (NMR). All isolates were evaluated for their cytotoxic activities. The heteroatom-containing new compounds 2 and 4 showed potent cytotoxicity to the human hepatoma tumor cell Bel7402 with IC₅₀ values of 7.63 ± 1.46, 13.14 ± 1.41 μM and the human fibrosarcoma tumor cell HT1080 with IC₅₀ values of 10.22 ± 1.32, 16.53 ± 1.67 μM, respectively.

Xanthone-derived polyketides from the Thai mangrove endophytic fungus Phomopsis sp. xy21

Six new xanthone-derived polyketides, named phomoxanthones F-K (1-6), along with three known ones, were isolated from Phomopsis sp. xy21, which was isolated as an endophytic fungus from the Thai mangrove Xylocarpus granatum. Phomoxanthone F (1) represents the first xanthone-derived polyketide containing a 10a-decarboxylated benzopyranone nucleus that was substituted by a 4-methyldihydrofuran-2(3H)-one moiety at C10a. Phomoxanthones G (2) and H (3) are highly oxidized xanthone-derived polyketides containing a novel 5-methyl-6-oxabicyclo[3.2.1]octane motif. This is the first report of a C6-O-C12 bridge in xanthone-derived polyketides. Additionally, a plausible biogenetic pathway for these xanthone-derived polyketides is proposed.

Peniginsengins B⁻E, New Farnesylcyclohexenones from the Deep Sea-Derived Fungus Penicillium sp. YPGA11

Chemical examination of the EtOAc extract of the deep sea-derived fungus Penicillium sp. YPGA11 resulted in the isolation of four new farnesylcyclohexenones, peniginsengins B–E (1–4), and a known analog peniginsengin A (5). The structures of compounds 1–4 were determined on the basis of comprehensive analyses of the nuclear magnetic resonance (NMR) and mass spectroscopy (MS) data, and the absolute configurations of 1, 2, and 4 were determined by comparisons of experimental electronic circular dichroism (ECD) with calculated ECD spectra. Compounds 1–5, characterized by a highly oxygenated 1-methylcyclohexene unit and a (4E,8E)-4,8-dimethyldeca-4,8-dienoic acid side chain, are rarely found in nature. Compounds 2–4 exhibited antibacterial activity against Staphylococcus aureus.

Marine-Derived Penicillium Species as Producers of Cytotoxic Metabolites

Since the discovery of penicillin, Penicillium has become one of the most attractive fungal genera for the production of bioactive molecules. Marine-derived Penicillium has provided numerous excellent pharmaceutical leads over the past decades. In this review, we focused on the cytotoxic metabolites * (* Cytotoxic potency was referred to five different levels in this review, extraordinary (IC₅₀/LD₅₀: <1 μM or 0.5 μg/mL); significant (IC₅₀/LD₅₀: 1~10 μM or 0.5~5 μg/mL); moderate (IC₅₀/LD₅₀: 10~30 μM or 5~15 μg/mL); mild (IC₅₀/LD₅₀: 30~50 μM or 15~25 μg/mL); weak (IC₅₀/LD₅₀: 50~100 μM or 25~50 μg/mL). The comparative potencies of positive controls were referred when they were available). produced by marine-derived Penicillium species, and on their cytotoxicity mechanisms, biosyntheses, and chemical syntheses.

Asperspiropene A, a novel fungal metabolite as an inhibitor of cancer-associated mutant isocitrate dehydrogenase 1

In silico screening of an in-house natural product database and confirmatory bioassays led to the identification of asperspiropene A (1) as an inhibitor of cancer-associated mutant IDH1.

Marine natural products sourced from marine-derived Penicillium fungi

Marine micro-organisms have been proven to be a major source of marine natural products (MNPs) in recent years, in which filamentous fungi are a vital source of bioactive natural products for their large metagenomes and more complex genetic backgrounds. This review highlights the 390 new MNPs from marine-derived Penicillium fungi during 1991 to 2014. These new MNPs are categorized based on the environment sources of the fungal hosts and their bioactivities are summarized.

New compound with DNA Topo I inhibitory activity purified from Penicillium oxalicum HSY05

Strain HSY05 was isolated from sea sediment collected from the South China Sea and was later identified as Penicillium oxalicum by 16S rDNA sequence analysis. Various chromatographic processes led to the isolation and purification of two metabolites from the fermentation culture of HSY05, including one new compound, 2,2',4,4'-tetrahyoxy-8'-methyl-6-methoxy-acyl-ethyl-diphenylmethanone (1), and a known compound secalonic acid D (SAD, 2), as characterised by UV, IR, 1D, 2D-NMR and MS data. The inhibitory activities against topoisomerase I of these two compounds were evaluated. The result showed that in addition to the known topo I inhibitor SAD (2), compound 1 also exhibited a moderate inhibitory effect.

Acetylcholinesterase inhibition effects of marine fungi

CONTEXT

To this day, there are no reports that marine compounds isolated from microorganisms of the Lianyungang area of China have been used for the treatment of Alzheimer's disease.

OBJECTIVE

The present study was to isolate fungi from the sea sediment of the Lianyungang area and screen for acetylcholineseterase inhibition activities of ethyl acetate extracts.

MATERIALS AND METHODS

Fungi were isolated from the sea sediment and fermented. After centrifugation, the supernate was extracted with ethyl acetate. The ethyl acetate extract was then fractionated into five fractions. Acetylcholinesterase inhibition activities of the ethyl acetate extracts and five sub-fractions were tested at a concentration of 500 μg/mL with the Ellman's method.

RESULTS

Forty-three marine fungi were isolated; 15 extracts inhibited acetylcholinestrease >50% and 3 extracts inhibited the acetylcholinesterase >80% at the concentration of 500 μg/mL. The 3 extracts (L1705, S1101, SH0701) inhibited AChE dose-dependently with IC₅₀ values of 11.3 ± 1.2, 72.1 ± 2.3, and 7.8 ± 2.8 μg/mL, respectively. After the extract of SH0701 was fractionated into five fractions, the ethyl acetate fraction possessed the highest acetylcholinesterase inhibitory activity with an inhibition rate of 71.55% at the concentration of 10 μg/mL. The fungus SH0701 was identified as Aspergillus ochraceus SH0701 according to morphology and molecular identification.

DISCUSSION AND CONCLUSION

The present results indicates that some ethyl acetate extracts of marine fungi isolated from Lianyungang area of China could inhibit AChE potently. Therefore, some novel AChE inhibitors might exist in those extracts.

Two new cytotoxic indole alkaloids from a deep-sea sediment derived metagenomic clone

Two new indole alkaloids, metagenetriindole A (1) and metagenebiindole A (2), were identified from deep-sea sediment metagenomic clone derived Escherichia coli fermentation broth. The structures of new compounds were elucidated by spectroscopic methods. The two new indole alkaloids demonstrated moderately cytotoxic activity against CNE2, Bel7402 and HT1080 cancer cell lines in vitro.

Marine natural products

This review covers the literature published in 2012 for marine natural products, with 1035 citations (673 for the period January to December 2012) 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 (1241 for 2012), together with the relevant biological activities, source organisms and country of origin. Biosynthetic studies, first syntheses, and syntheses that lead to the revision of structures or stereochemistries, have been included.

Differential proteomic analysis of HL60 cells treated with secalonic acid F reveals caspase 3-induced cleavage of Rho GDP dissociation inhibitor 2

Secalonic acid F (SAF) has been previously identified, however, little is known about its cytotoxic activity and related cytotoxic mechanism. The aim of this study was to evaluate the cytotoxic activity of SAF isolated from a deep sea originated fungus Penicillium sp. F11 in HL60 cells and to analyze the differences in protein expression of HL60 cells treated with SAF. The CCK-8 assay and Annexin V-FLUOS/PI assay indicated that SAF displayed dose- and time-dependent inhibition of HL60 cell proliferation and induced apoptosis. Two-dimensional gel electrophoresis (2-DE) analysis of HL60 cells treated with SAF (4 µg/ml) revealed 10 differentially expressed protein spots (P<0.05), 5 upregulated and 5 downregulated. Three spots (1 downregulated and 2 upregulated) were identified as Rho GDP dissociation inhibitor 2 (RhoGDI 2) proteins by MALDI-TOF MS. Western blotting further demonstrated the decreased abundance of full-length RhoGDI 2 together with the increased abundance of caspase 3-cleaved product of RhoGDI 2. The caspase 3 inhibitor Ac-DEVD-CHO could suppress the cytotoxic effect of SAF and significantly block the cleavage of RhoGDI 2. RhoGDI 2 is a cytosolic regulator of Rho GTPase and the caspase 3-cleaved product of RhoGDI 2 can advance progression of the apoptotic process. Our data showed that SAF may modulate RhoGDI 2 levels in HL60 cells, thereby potentially disrupting cell signaling pathways important for HL60 cell function.