Cytotoxic Secondary Metabolites Isolated from the Marine Alga-Associated Fungus Penicillium chrysogenum LD-201810

Granulathiazole A protects 6-OHDA-induced Parkinson's disease from ferroptosis via activating Nrf2/HO-1 pathway

Two pairs of enantiomers (1a-2b), namely (±)-alterpyrone F and (±)-alterpyrone G, along with a rare benzothiazole meroterpenoid granulathiazole A (3, GA), and two undescribed compounds called respectively granulahydeoate (4) and granulaone (5), were obtained from the co-cultivation of Alternaria brassicicola and Penicillium sp. HUBU0120. Exhaustive analyses of NMR, single crystal XRD, Mo2(OAc)4-induced circular dichroism data, and a modified Mosher's method distinguished the absolute configurations of isolates. Bioactive evaluations exhibited that GA possessed promising anti-PD activity in both in vitro and in vivo PD models viz. 6-OHDA-induced SH-SY5Y cells and 6-OHDA-induced zebrafish, respectively. Moreover, our research demonstrated that ferroptosis activated by 6-OHDA was mitigated in PD models after treated with GA. Extensive molecular mechanism studies in PD-modelled cells manifested that GA attenuated the decreased expressions of SLC7A11, GPX4, and FSP-1, and the increased level of ACSL4 via activating Nrf2/HO-1 pathway as well as ameliorated the accumulation of α-synuclein.

A comprehensive review on the medicinally valuable endosymbiotic fungi Penicillium chrysogenum

Recently, it has been shown that metabolites derived from endosymbiotic fungi attracted high attention, since plenty of them have promising pharmaceutical applications. The variation of metabolic pathways in fungi is considered an optimistic source for lead compounds. Among these classes are terpenoids, alkaloids, polyketides, and steroids, which have proved several pharmacological activities, including antitumor, antimicrobial, anti-inflammatory, and antiviral actions. This review concludes the major isolated compounds from different strains of Penicillium chrysogenum during the period 2013-2023, together with their reported pharmacological activities. From literature surveys, 277 compounds have been identified from P. chrysogenum, which has been isolated as an endosymbiotic fungus from different host organisms, with specific attention paid to those showing marked biological activities that could be useful in the pharmaceutical industry in the future. This review represents documentation for a valuable reference for promising pharmaceutical applications or further needed studies on P. chrysogenum.

Structure Revisions of Phenolic Bisabolane Sesquiterpenes and a Ferroptosis Inhibitor from the Marine-Derived Fungus Aspergillus versicolor YPH93

Seven new phenolic bisabolane sesquiterpenoids (1-7), along with 10 biogenetically related analogues (8-17), were obtained from the deep-sea-derived fungus Aspergillus versicolor YPH93. The structures were elucidated based on extensive analyses of the spectroscopic data. Compounds 1-3 are the first examples of phenolic bisabolanes that contain two hydroxy groups attached to the pyran ring. The structures of sydowic acid derivatives (1-6 and 8-10) were carefully studied, leading to the structure revisions of six known analogues, including a revision of the absolute configuration for sydowic acid (10). All metabolites were evaluated for their effects on ferroptosis. Compound 7 exerted inhibition on erastin/RSL3-induced ferroptosis with EC50 values ranging from 2 to 4 μM, while it exhibited no effects on TNFα-induced necroptosis or H2O2-induced cell necrosis.

Cytotoxic indole alkaloids and polyketides produced by a marine-derived fungus Aspergillus flavipes DS720

Marine-derived microorganisms possess the unique metabolic pathways to produce structurally novel secondary metabolites with potent biological activities. In this study, bioactivity-guided isolation of the marine deep-sea-derived fungus Aspergillus flavipes DS720 led to the characterization of four indole alkaloids (compounds 1–4) and four polyketides (compounds 5–8), such as two new indoles, flavonoids A (1) and B (2) with a C-6 reversed prenylation, and a new azaphilone, flaviazaphilone A (5). Their chemical structures were unambiguously established by an extensive interpretation of spectroscopic data, such as 1D/2D NMR and HRESIMS data. The absolute configurations of the new compound 5 were solved by comparing the experimental and calculated Electronic Circular Dichroism (ECD) spectra. Since sufficient amount of flavonoids A (1) was obtained, 1 was subjected to a large-scale cytotoxic activity screening against 20 different human tumor cell lines. The results revealed that 1 showed broad-spectrum cytotoxicities against HeLa, 5637, CAL-62, PATU8988T, A-375, and A-673 cell lines, with the inhibition rates of more than 90%. This study indicated that the newly discovered indole alkaloid 1 may possess certain potential for the development of lead compounds in the future.

Natural bioactive compounds from marine fungi (2017-2020)

Secondary metabolites generated by marine fungi have relatively small molecular weights and excellent activities and have become an important source for developing drug lead compounds. The review summarizes the structures of novel small-molecule compounds derived from marine fungi in recent years; introduces representative monomers in antimicrobial, antitumor, anti-viral, and anti-neuritis aspects; and discusses their biological activities and molecular mechanisms. This review will act as a guide for further discovering marine-derived drugs with novel chemical structures and specific targeting mechanisms.

Marine natural products

Covering: 2020This review covers the literature published in 2020 for marine natural products (MNPs), with 757 citations (747 for the period January to December 2020) 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 (1407 in 420 papers for 2020), together with the relevant biological activities, source organisms and country of origin. Pertinent reviews, biosynthetic studies, first syntheses, and syntheses that led to the revision of structures or stereochemistries, have been included. A meta analysis of bioactivity data relating to new MNPs reported over the last five years is also presented.

New Enantiomers of a Nor-Bisabolane Derivative and Two New Phthalides Produced by the Marine-Derived Fungus Penicillium chrysogenum LD-201810

Marine-derived fungi are a treasure house for the discovery of structurally novel secondary metabolites with potential pharmaceutical value. In this study, a pair of new nor-bisabolane derivative enantiomers (±)−1 and two new phthalides (4 and 5), as well as four known metabolites, were isolated from the culture filtrate of the marine algal-derived endophytic fungus Penicillium chrysogenum LD-201810. Their structures were established by detailed interpretation of spectroscopic data (1D/2D NMR and ESI-MS). The optical resolution of compound (±)−1 by chiral HPLC successfully afforded individual enantiomers (+)−1 and (−)−1, and their absolute configurations were determined by TDDFT-ECD calculations. Compound (±)−1 represents the first example of bisabolane analogs with a methylsulfinyl substituent group, which is rare in natural products. All of the isolated compounds 1–7 were evaluated for their cytotoxic activity against A549, BT-549, HeLa, HepG2, MCF-7, and THP-1 cell lines, as well as for antifungal activity against four plant pathogenetic fungi (Alternaria solani, Botrytis cinerea, Fusarium oxysporum, and Valsa mali). Compound 2, a bisabolane-type sesquiterpenoid, was shown to possess excellent activity for control of B. cinerea with half-maximal inhibitory concentration (IC₅₀) of 13.6 μg/mL, whereas the remaining investigated compounds showed either weak or no cytotoxic/antifungal activity in this study.

Marine Natural Products as Anticancer Agents

Cancer remains one of the major threats to human health and one of the deadliest diseases worldwide [...].