Chrysamides A–C, Three Dimeric Nitrophenyl trans-Epoxyamides Produced by the Deep-Sea-Derived Fungus Penicillium chrysogenum SCSIO41001

Retrobisabolane A, a Novel Bisabolane-Derived Sesquiterpenoid Isolated from Deep-Sea-Derived Fungus Retroconis fusiformis MCCC 3A00792

One novel bisabolane-derived sesquiterpenoid retrobisabolane A (1), featuring a methyl group location at the C-4 position instead of C-3 in the bisabolanes, and a known ester-substituted eremophilane-type sesquiterpenoid cryptosphaerolide (2), along with three known indole alkaloids (3-5) were discovered from the fermented cultures of a deep-sea-derived fungus Retroconis fusiformis MCCC 3A00792. The planar structure of new compound 1 was determined by extensive analysis of the NMR and HRESIMS spectra. The relative and absolute configurations of 1 were resolved by the coupling constant (J), calculation of ECD and NMR spectra, and the DP4+ probability analysis of the 1H and 13C NMR data. Interestingly, retrobisabolane A was the new subclass of bisabolanes bearing a methyl group linkage at C-4 instead of C-3 position. Three human cancer cell lines (Hela, AGS, and BIU-87) were subjected to evaluate the cytotoxic activities of compounds 1-5. As a result, compound 2 exhibited significant inhibitory activities against three cell lines with IC50 values ranging from 9.95 to 18.77 μM.

Immunomodulatory Compounds from the Sea: From the Origins to a Modern Marine Pharmacopoeia

From sea shores to the abysses of the deep ocean, marine ecosystems have provided humanity with valuable medicinal resources. The use of marine organisms is discussed in ancient pharmacopoeias of different times and geographic regions and is still deeply rooted in traditional medicine. Thanks to present-day, large-scale bioprospecting and rigorous screening for bioactive metabolites, the ocean is coming back as an untapped resource of natural compounds with therapeutic potential. This renewed interest in marine drugs is propelled by a burgeoning research field investigating the molecular mechanisms by which newly identified compounds intervene in the pathophysiology of human diseases. Of great clinical relevance are molecules endowed with anti-inflammatory and immunomodulatory properties with emerging applications in the management of chronic inflammatory disorders, autoimmune diseases, and cancer. Here, we review the historical development of marine pharmacology in the Eastern and Western worlds and describe the status of marine drug discovery. Finally, we discuss the importance of conducting sustainable exploitation of marine resources through biotechnology.

Antitumor aspochalasin and antiviral benzofuran derivatives from a marine-derived fungus Aspergillus sp. SCSIO41032

Chemical investigation of the EtOAc extract of a deep-sea derived fungus Aspergillus sp. SCSIO41032 resulted in the isolation of ten known compounds, including eight aspochalasins. Their structures were elucidated by using extensive NMR spectroscopic, mass spectrometric and single crystal X-ray diffraction analysis. The detailed crystallographic data for structures 1, 2, and 4, along with the relative configurations of aspochalasin E (3) determined by its acetonide derivative were reported for the first time. The results of antitumor and antiviral activities showed that 3 displayed moderate antitumor activities against 22Rv1, PC-3, A549, and HCT-15 cell lines with IC50 values ranged from 5.9 ± 0.8 to 19.0 ± 7.7 μM, and 9 exhibited moderate antiviral activities against HSV-1/2 with EC50 values of 9.5 ± 0.5 and 5.4 ± 0.6 μM, respectively. Plate clone formation assays results indicated that 3 inhibited the 22Rv1, PC-3 cells growth in a dose-dependent manner.

The potential of marine-derived piperazine alkaloids: Sources, structures and bioactivities

Marine-derived piperazine alkaloids (MDPAs) constitute a significant group of natural compounds known for their diverse structures and biological activities. Over the past five decades, substantial efforts have been devoted to isolating these alkaloids from marine sources and characterizing their chemical and bioactive profiles. To date, a total of 922 marine-derived piperazine alkaloids have been reported from various marine organisms. These compounds demonstrate a wide range of pharmacological properties, including cytotoxicity, antibacterial, antifungal, antiviral, and various other activities. Notably, among these activities, cytotoxicity emerges as the most prominent characteristic of marine-derived piperazine alkaloids. This review also summarizes the structure-activity relationship (SAR) studies associated with the cytotoxicity of these compounds. In summary, our objective is to provide an overview of the research progress concerning marine-derived piperazine alkaloids, with the aim of fostering their continued development and utilization.

Secondary metabolites from Aspergillus terreus F6-3, a marine fungus associated with Johnius belengerii

Two new terrein derivatives asperterreinones A-B (1-2), one new octahydrocoumarin derivative (±)-asperterreinin A (6), along with seventeen known compounds, were isolated from Aspergillus terreus F6-3, a marine fungus associated with Johnius belengerii. The structures of 1, 2, and 6 were established on the basis of 1D and 2D NMR, mass spectroscopy, comparative electronic circular dichroism (ECD) spectra analysis, density functional theory calculation of 13C NMR, and DP4+ probability analysis. Among all the isolates, eurylene (7), a constituent of the Malaysian medicinal plant Eurycoma longifolia, was obtained from a microbial source for first time. In the in vitro bioassay, 11 and 13 showed potent inhibitory activity against the Escherichia coli β-glucuronidase (EcGUS) with IC50 values of 27.75 ± 0.73 and 17.73 ± 0.81 μM, respectively. It was the first time that questinol (11) and (±)-aspertertone B (13) were reported as potent EcGUS inhibitors.

Discovery, bioactivity and biosynthesis of fungal piperazines

Covering: up to the end of July, 2022Fungi are prolific producers of piperazine alkaloids, which have been shown to exhibit an array of remarkable biological activities. Since the first fungal piperazine, herquline A, was reported from Penicillium herquei Fg-372 in 1979, a plethora of structurally diverse piperazines have been isolated and characterised from various fungal strains. Significant advancements have been made in recent years towards unravelling the biosynthesis of fungal piperazines and numerous synthetic routes have been proposed. This review provides a comprehensive summary of the current knowledge of the discovery, classification, bioactivity and biosynthesis of piperazine alkaloids reported from fungi, and discusses the perspectives for exploring the structural diversity of fungal piperazines via genome mining of the untapped piperazine biosynthetic pathways.

Three unusual hybrid sorbicillinoids with anti-inflammatory activities from the deep-sea derived fungus Penicillium sp. SCSIO06868

Under the guidance of MS/MS based molecular networking, bisorbicillchaetones A-C, three undescribed hybrid sorbicillinoids, were isolated from cultures of the deep-sea derived fungus Penicillium sp. SCSIO06868. The planar structures and absolute configurations of these compounds were determined by extensive spectroscopic analyses. Bisorbicillchaetones are the first examples of hybrid sorbicillinoids containing a coniochaetone unit. Bisorbicillchaetones A and B exhibited moderate inhibitory effect on NO production in LPS activated RAW264.7 cells with the IC₅₀ values of 80.3 ± 3.6 μM and 38.4 ± 3.3 μM, respectively, without cytotoxicity observed.

Immune Repertoire and Advancements in Nanotherapeutics for the Impediment of Severe Steroid Resistant Asthma (SSR)

Severe steroid-resistant asthma (SSR) patients do not respond to the corticosteroid therapies due to the heterogeneity, and genome-wide variations. However, there are very limited reports pertinent to the molecular signaling underlying SSR and making pharmacologists, and formulation scientists to identify the effective therapeutic targets in order to produce novel therapies using novel drug delivery systems (NDDS). We have substantially searched literature for the peer-reviewed and published reports delineating the role of glucocorticoid-altered gene expression, and the mechanisms responsible for SSR asthma, and NDDS for treating SSR asthma using public databases PubMed, National Library of Medicine (NLM), google scholar, and medline. Subsequently, we described reports underlying the SSR pathophysiology through several immunological and inflammatory phenotypes. Furthermore, various therapeutic strategies and the role of signaling pathways such as mORC1-STAT3-FGFBP1, NLRP3 inflammasomes, miR-21/PI3K/HDAC2 axis, PI3K were delineated and these can be considered as the therapeutic targets for mitigating the pathophysiology of SSR asthma. Finally, the possibility of nanomedicine-based formulation and their applications in order to enhance the long term retention of several antioxidant and anti-asthmatic drug molecules as a significant therapeutic modality against SSR asthma was described vividly.

New Antibacterial Chloro-Containing Polyketides from the Alga-Derived Fungus Asteromyces cruciatus KMM 4696

Six new polyketides acrucipentyns A–F (1–6) were isolated from the alga-derived fungus Asteromyces cruciatus KMM 4696. Their structures were established based on spectroscopic methods. The absolute configurations of acrucipentyn A was assigned by the modified Mosher’s method and ROESY data analysis. Acrucipentyns A–E were identified to be the very first examples of chlorine-containing asperpentyn-like compounds. The cytotoxic and antimicrobial activities of the isolated compounds were examined. Acrucipentyns A–F were found as antimicrobial agents, which inhibited sortase A enzyme activity, bacterial growth and biofilm formation of Staphylococcus aureus and decreased LDH release from human keratinocytes HaCaT in S. aureus skin infection in an in vitro model.

Recent Achievements in Total Synthesis for Integral Structural Revisions of Marine Natural Products

A great effort to discover new therapeutic ingredients is often initiated through the discovery of the existence of novel marine natural products. Since substances produced by the marine environment might be structurally more complex and unique than terrestrial natural products, there have been cases of misassignments of their structures despite the availability of modern spectroscopic and computational chemistry techniques. When it comes to refutation to erroneously or tentatively proposed structures empirical preparations through organic chemical synthesis has the greatest contribution along with close and sophiscated inspection of spectroscopic data. Herein, we analyzed the total synthetic studies that have decisively achieved in revelation of errors, ambiguities, or incompleteness of the isolated structures of marine natural products covering the period from 2018 to 2021.

A Treasure of Bioactive Compounds from the Deep Sea

The deep-sea environment is a unique, challenging extreme habitat where species have had to adapt to the absence of light, low levels of oxygen, high pressure and little food. In order to survive such harsh conditions, these organisms have evolved different biochemical and physiological features that often have no other equivalent in terrestrial habitats. Recent analyses have highlighted how the deep sea is one of the most diverse and species-rich habitats on the planet but less explored compared to more accessible sites. Because of their adaptation to this extreme environment, deep-sea species have the potential to produce novel secondary metabolites with potent biological activities. Recent advances in sampling and novel techniques in microorganism culturing and chemical isolation have promoted the discovery of bioactive agents from deep-sea organisms. However, reports of natural products derived from deep-sea species are still scarce, probably because of the difficulty in accessing deep-sea samples, sampling costs and the difficulty in culturing deep-sea organisms. In this review, we give an overview of the potential treasure represented by metabolites produced by deep marine species and their bioactivities for the treatment and prevention of various human pathologies.

Marine-Derived Compounds for the Potential Treatment of Glucocorticoid Resistance in Severe Asthma

One of the challenges to the management of severe asthma is the poor therapeutic response to treatment with glucocorticosteroids. Compounds derived from marine sources have received increasing interest in recent years due to their prominent biologically active properties for biomedical applications, as well as their sustainability and safety for drug development. Based on the pathobiological features associated with glucocorticoid resistance in severe asthma, many studies have already described many glucocorticoid resistance mechanisms as potential therapeutic targets. On the other hand, in the last decade, many studies described the potentially anti-inflammatory effects of marine-derived biologically active compounds. Analyzing the underlying anti-inflammatory mechanisms of action for these marine-derived biologically active compounds, we observed some of the targeted pathogenic molecular mechanisms similar to those described in glucocorticoid (GC) resistant asthma. This article gathers the marine-derived compounds targeting pathogenic molecular mechanism involved in GC resistant asthma and provides a basis for the development of effective marine-derived drugs.

New Tetramic Acid Derivatives From the Deep-Sea-Derived Fungus Penicillium sp. SCSIO06868 With SARS-CoV-2 Mpro Inhibitory Activity Evaluation

Three new tetramic acid derivatives (1–3) and a new polyketide (4) along with eight known compounds (5–12) were isolated from cultures of the deep-sea-derived fungus Penicillium sp. SCSIO06868. Four new structures were elucidated by analysis of one-dimensional/two-dimensional nuclear magnetic resonance (NMR) data and high-resolution electrospray ionization mass spectrometry. Their absolute configurations were established by X-ray crystallography analysis and comparison of the experimental and reported electronic circular dichroism (ECD) values or specific optical rotation. Compound 3 exhibited potent, selective inhibitory activities against Staphylococcus aureus and methicillin-resistant S. aureus with minimum inhibitory concentration values of both 2.5 μg/ml. Also, compound 3 showed weak antiviral activity against severe acute respiratory syndrome coronavirus 2 main protease, which was responsible for the coronavirus disease 2019 pandemic.

Discovery of a novel inhibitor of nitric oxide production with potential therapeutic effect on acute inflammation

Inflammation as a host's excessive immune response to stimulation, is involved in the development of numerous diseases. To discover novel anti-inflammatory agents and based on our previous synthetic work on marine natural product Chrysamide B, it and a series of derivatives were synthesized and evaluated for their anti-inflammatory activity on inhibition of LPS-induced NO production. Then the preliminary structure-activity relationships were conducted. Among them, Chrysamide B is the most potent anti-inflammatory agent with low cytotoxicity and strong inhibition on the production of NO (IC₅₀ = 0.010 μM) and the activity of iNOS (IC₅₀ = 0.082 μM) in LPS-stimulated RAW 264.7 cells. Primary studies suggested that the mechanism of action may be that it interfered the formation of active dimeric iNOS but not affected transcription and translation. Furthermore, its good performance of anti-inflammatory effect on LPS-induced multiple inflammatory cytokines production, carrageenan-induced paw edema, and endotoxin-induced septic mice, was observed. We believe that these findings would provide an idea for the further modification and research of these analogs in the future.

Design, synthesis and antitumor activity evaluation of Chrysamide B derivatives

Marine natural products derived from special or extreme environment provide an important source for the development of anti-tumor drugs due to their special skeletons and functional groups. In this study, based on our previous work on the total synthesis and structure revision of the novel marine natural product Chrysamide B, a group of its derivatives were designed, synthesized, and subsequently of which the anti-cancer activity, structure-activity relationships and cellular mechanism were explored for the first time. Compared with Chrysamide B, better anti-cancer performance of some derivatives against five human cancer cell lines (SGC-7901, MGC-803, HepG2, HCT-116, MCF-7) was observed, especially for compound b-9 on MGC-803 and SGC-7901 cells with the IC ₅₀ values of 7.88 ± 0.81 and 10.08 ± 1.08 μM, respectively. Subsequently, cellular mechanism study suggested that compound b-9 treatment could inhibit the cellular proliferation, reduce the migration and invasion ability of cells, and induce mitochondrial-dependent apoptosis in gastric cancer MGC-803 and SGC-7901 cells. Furthermore, the mitochondrial-dependent apoptosis induced by compound b-9 is related with the JAK2/STAT3/Bcl-2 signaling pathway. To conclude, our results offer a new structure for the discovery of anti-tumor lead compounds from marine natural products.

Recent Advances in the Use of the Dimerization Strategy as a Means to Increase the Biological Potential of Natural or Synthetic Molecules

The design of C₂-symmetric biologically active molecules is a subject of interest to the scientific community. It provides the possibility of discovering medicine with higher biological potential than the parent drugs. Such molecules are generally produced by classic chemistry, considering the shortness of reaction sequence and the efficacy for each step. This review describes and analyzes recent advances in the field and emphasizes selected C₂-symmetric molecules (or axial symmetric molecules) made during the last 10 years. However, the description of the dimers is contextualized by prior work allowing its development, and they are categorized by their structure and/or by their properties. Hence, this review presents dimers composed of steroids, sugars, and nucleosides; known and synthetic anticancer agents; polyphenol compounds; terpenes, known and synthetic antibacterial agents; and natural products. A special focus on the anticancer potential of the dimers transpires throughout the review, notwithstanding their structure and/or primary biological properties.

Cellular Signal Transductions and Their Inhibitors Derived from Deep-Sea Organisms

Not only physiological phenomena but also pathological phenomena can now be explained by the change of signal transduction in the cells of specific tissues. Commonly used cellular signal transductions are limited. They consist of the protein-tyrosine kinase dependent or independent Ras-ERK pathway, and the PI3K-Akt, JAK-STAT, SMAD, and NF-κB-activation pathways. In addition, biodegradation systems, such as the ubiquitin-proteasome pathway and autophagy, are also important for physiological and pathological conditions. If we can control signaling for each by a low-molecular-weight agent, it would be possible to treat diseases in new ways. At present, such cell signaling inhibitors are mainly looked for in plants, soil microorganisms, and the chemical library. The screening of bioactive metabolites from deep-sea organisms should be valuable because of the high incidence of finding novel compounds. Although it is still an emerging field, there are many successful examples, with new cell signaling inhibitors. In this review, we would like to explain the current view of the cell signaling systems important in diseases, and show the inhibitors found from deep-sea organisms, with their structures and biological activities. These inhibitors are possible candidates for anti-inflammatory agents, modulators of metabolic syndromes, antimicrobial agents, and anticancer agents.

Metabolites of Marine Sediment-Derived Fungi: Actual Trends of Biological Activity Studies

Marine sediments are characterized by intense degradation of sedimenting organic matter in the water column and near surface sediments, combined with characteristically low temperatures and elevated pressures. Fungi are less represented in the microbial communities of sediments than bacteria and archaea and their relationships are competitive. This results in wide variety of secondary metabolites produced by marine sediment-derived fungi both for environmental adaptation and for interspecies interactions. Earlier marine fungal metabolites were investigated mainly for their antibacterial and antifungal activities, but now also as anticancer and cytoprotective drug candidates. This review aims to describe low-molecular-weight secondary metabolites of marine sediment-derived fungi in the context of their biological activity and covers research articles published between January 2016 and November 2020.

Marine Pharmacology in 2016-2017: Marine Compounds with Antibacterial, Antidiabetic, Antifungal, Anti-Inflammatory, Antiprotozoal, Antituberculosis and Antiviral Activities; Affecting the Immune and Nervous Systems, and Other Miscellaneous Mechanisms of Action

The review of the 2016-2017 marine pharmacology literature was prepared in a manner similar as the 10 prior reviews of this series. Preclinical marine pharmacology research during 2016-2017 assessed 313 marine compounds with novel pharmacology reported by a growing number of investigators from 54 countries. The peer-reviewed literature reported antibacterial, antifungal, antiprotozoal, antituberculosis, and antiviral activities for 123 marine natural products, 111 marine compounds with antidiabetic and anti-inflammatory activities as well as affecting the immune and nervous system, while in contrast 79 marine compounds displayed miscellaneous mechanisms of action which upon further investigation may contribute to several pharmacological classes. Therefore, in 2016-2017, the preclinical marine natural product pharmacology pipeline generated both novel pharmacology as well as potentially new lead compounds for the growing clinical marine pharmaceutical pipeline, and thus sustained with its contributions the global research for novel and effective therapeutic strategies for multiple disease categories.

Structurally various sorbicillinoids from the deep-sea sediment derived fungus Penicillium sp. SCSIO06871

Two new hybrid sorbicillinoids (1 and 5), three new bisorbicillinoids (2-4), and three monomeric sorbicillinoids (6-8), along with eighteen known sorbicillinoids (9-26) were isolated from cultures of the deep-sea sediment derived fungus Penicillium sp. SCSIO06871. Their structures and absolute configurations were elucidated based upon the extensive spectroscopic analysis, X-ray crystallography analysis and the comparison of the experimental and calculated ECD data. Bisorbicillpyrone A (4) is the first example of bisorbicillinoid containing an α-pyrone derivative unit. All of the isolated compounds were evaluated for their antibacterial, antifungal and enzyme inhibitory activities against α-glycosidase and acetylcholinesterase (AChE) in vitro. Compound 6 displayed more potent inhibitory activity against α-glycosidase than acarbose with IC₅₀ value of 36.0 μM and compounds 4, 12, 18, 22, 23 exhibited moderate inhibitory activity with IC₅₀ values ranging from 115.8 to 208.5 μM. Compounds 10 and 22 showed weak enzyme inhibitory activities against AChE with 55.1% and 51.1% inhibitions at concentration of 50 μg/mL, respectively. Besides, compounds 11 and 12 exhibited significant antibacterial activities against Staphylococcus aureus with MIC values of 10.0 and 5.0 μg/mL, respectively. The hypothetical biosynthetic pathway of the isolated sorbicillinoids with three different structural types was discussed.

Molecules derived from the extremes of life: a decade later

Covering: Early 2008 until the end of 2019Microorganisms which survive (extreme-tolerant) or even prefer (extremophilic) living at the limits of pH, temperature, salinity and pressure found on earth have proven to be a rich source of novel structures. In this update we summarise the wide variety of new molecules which have been isolated from extremophilic and extreme-tolerant microorganisms since our original 2009 review, highlighting the range of bioactivities these molecules have been reported to possess.

Fungi: outstanding source of novel chemical scaffolds

A large number of remarkable studies on the secondary metabolites of fungi have been conducted in recent years. This review gives an overview of one hundred and sixty-seven molecules with novel skeletons and their bioactivities that have been reported in seventy-nine articles published from 2013 to 2017. Our statistical data showed that endophytic fungi and marine-derived fungi are the major sources of novel bioactive secondary metabolites.

Novel 3,4-seco-3,19-dinorspongian and 5,17-epoxy-19-norspongian diterpenes from the marine sponge Spongia sp

Twelve new norspongian diterpenes, dinorspongians A-F (1–6) and epoxynorspongians A–F (7–12), were isolated from the marine sponge Spongia sp.

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.

(+)- and (-)-Spongiterpene, a pair of new valerenane sesquiterpene enantiomers from the marine sponge Spongia Sp

(+)- and (-)-Spongiterpene [(+)-1 and (-)-1], a pair of new valerenane sesquiterpene enantiomers, along with four known compounds (2-5) were isolated from the marine sponge Spongia sp. The structures of (+)-1 and (-)-1 including absolute configurations were determined by spectroscopic analysis, quantum chemical calculation and X-ray diffraction. Compounds (+)-1 and (-)-1 were the first examples of valerenane sesquiterpenes isolated from the marine sponges. The cytotoxic activities of (+)-1 and (-)-1 were also evaluated.

Griseofulvin Derivatives: Synthesis, Molecular Docking and Biological Evaluation

Background:

Griseofulvin - a mold metabolite produced by Penisilium griseofulvum is known as an antifungal drug.

Objective:

Thus, the goal of this paper is the design and synthesis of new griseofulvin derivatives and evaluation of their antifungal activity.

Methods:

Forty-two new compounds were synthesized using classical methods of organic synthesis and evaluated for their antimicrobial activity by microdilution method.

Results:

All forty-two new compounds exhibited very good activity against eight tested micromycetes with MIC ranging from 0.0075-0.055 mg/ml and MFC from 0.02-024 mg/ml. All compounds exhibited better activity than reference drugs ketoconazole (7-42 times) and bifonazole (3-16 fold). The most promising was compound 15. The most sensitive fungal was found to be T. viride, while the most resistant, as was expected, was A. fumigatus. It should be mentioned that most of compounds exhibited better activity than griseofulvin.

:

The molecular docking studies revealed that the most active compound have the same hydrophobic and H-bonding interactions with Thr276 residue observed for griseofulvin forming 3 hydrogen bonds while griseofulvin only one. In general, the molecular docking results coincide with experimental.

Conclusion:

Forty-two giseofulvin derivatives were designed, synthesized and evaluated for antimicrobial activity. These derivatives revealed good antifungal activity, better than reference drugs ketoconazole, bifonazole, and griseofulvin as well.

Dimeric 1,4-benzoquinone Derivatives with Cytotoxic Activities from the Marine-Derived Fungus Penicillium sp. L129

Two new dimeric 1,4-benzoquinone derivatives, peniquinone A (1) and peniquinone B (2), a new dibenzofuran penizofuran A (3), and a new pyrazinoquinazoline derivative quinadoline D (4), together with 13 known compounds (5-17), were isolated from a marine-derived fungus Penicillium sp. L129. Their structures, including absolute configurations, were elucidated by extensive spectroscopic data and electronic circular dichroism calculations. Compound 1 exhibited cytotoxicity against the MCF-7, U87 and PC3 cell lines with IC₅₀ values of 12.39 µM, 9.01 µM and 14.59 µM, respectively, while compound 2 displayed relatively weak cytotoxicity activities against MCF-7, U87 and PC3 cell lines with IC₅₀ values of 25.32 µM, 13.45 µM and 19.93 µM, respectively. Furthermore, compound 2 showed weak quorum sensing inhibitory activity against Chromobacterium violaceum CV026 with an MIC value of 20 μg/well.

(±) Cochlearoids N-P: three pairs of phenolic meroterpenoids from the fungus Ganoderma cochlear and their bioactivities

Three pairs of meroterpenoids (±) cochlearoids N-P (1-3) were isolated from the fruiting bodies of Ganoderma cochlear. Their structures including absolute configurations were assigned by spectroscopic techniques. All the isolated compounds were tested for their inhibitory activities toward BRD4, human cancer cells, and micro-organisms. The results show that the enantiomers of (±)-1 are BRD4 inhibitors, (-)-1 and (+)-3 are cytotoxic against human cancer cells (K562) with IC₅₀ values of 7.68 and 6.68 μM, respectively. Besides compounds (±)-2 and (±)-3 exhibit potent inhibitory activity against Staphylococcus aureus with IC₅₀ values in the range of 5.43-17.99 μM.

Phylogenomics Reveal the Dynamic Evolution of Fungal Nitric Oxide Reductases and Their Relationship to Secondary Metabolism

Fungi expressing P450nor, an unconventional nitric oxide (NO) reducing cytochrome P450, are considered significant contributors to environmental nitrous oxide (N₂O) emissions. Despite extensive efforts, fungal contributions to N₂O emissions remain uncertain. For example, the majority of N₂O emitted from antibiotic-amended soil microcosms is attributed to fungal activity, yet axenic fungal cultures do not couple N-oxyanion respiration to growth and these fungi produce only minor quantities of N₂O. To assist in reconciling these conflicting observations and produce a benchmark genomic analysis of fungal denitrifiers, genes underlying denitrification were examined in >700 fungal genomes. Of 167 p450nor—containing genomes identified, 0, 30, and 48 also harbored the denitrification genes narG, napA, or nirK, respectively. Compared with napA and nirK, p450nor was twice as abundant and exhibited 2–5-fold more gene duplications, losses, and transfers, indicating a disconnect between p450nor presence and denitrification potential. Furthermore, cooccurrence of p450nor with genes encoding NO-detoxifying flavohemoglobins (Spearman r = 0.87, p = 1.6e⁻¹⁰) confounds hypotheses regarding P450nor’s primary role in NO detoxification. Instead, ancestral state reconstruction united P450nor with actinobacterial cytochrome P450s (CYP105) involved in secondary metabolism (SM) and 19 (11%) p450nor-containing genomic regions were predicted to be SM clusters. Another 40 (24%) genomes harbored genes nearby p450nor predicted to encode hallmark SM functions, providing additional contextual evidence linking p450nor to SM. These findings underscore the potential physiological implications of widespread p450nor gene transfer, support the undiscovered affiliation of p450nor with fungal SM, and challenge the hypothesis of p450nor’s primary role in denitrification.

New Ansamycins from the Deep-Sea-Derived Bacterium Ochrobactrum sp. OUCMDZ-2164

Two new ansamycins, trienomycins H (1) and I (2), together with the known trienomycinol (3), were isolated from the fermentation broth of the deep-sea-derived bacterium Ochrobactrum sp. OUCMDZ-2164. Their structures, including their absolute configurations, were elucidated based on spectroscopic analyses, ECD spectra, and Marfey’s method. Compound 1 exhibited cytotoxic effects on A549 and K562 cell lines with IC₅₀ values of 15 and 23 μM, respectively.

Natural Products Research in China From 2015 to 2016

This review covers the literature published by chemists from China during the 2015-2016 on natural products (NPs), with 1,985 citations referring to 6,944 new compounds isolated from marine or terrestrial microorganisms, plants, and animals. The emphasis is on 730 new compounds with a novel skeleton or/and significant bioactivity, together with their source organism and country of origin.

Cochlearoids L and M: Two New Meroterpenoids from the Fungus Ganoderma cochlear

Cochlearoids L (1) and M (2), two new meroterpenoids and three known ones, were isolated from the fruiting bodies of Ganoderma cochlear. The new structures were elucidated by spectroscopic and chemical methods. Biological evaluation showed that 1 could inhibit bromodomain-containing protein 4 (BRD4) with IC50 value of 68.7 μM. Besides, 1 was found to have weak cytotoxic activities against three human cell lines (A549, K562, Huh-7) with IC50 values in the range of 39.6–190.0 μM.

Marine natural products

Covering: 2016. Previous review: Nat. Prod. Rep., 2017, 34, 235-294This review covers the literature published in 2016 for marine natural products (MNPs), with 757 citations (643 for the period January to December 2016) 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 (1277 in 432 papers for 2016), 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.

Total synthesis and structure revision of chrysamide B

Total synthesis and structure revision of chrysamide B are described, the strategy features a convergent assembly of the chiral piperazine core and epoxy-acid.

Survey of natural products reported by Asian research groups in 2016

The new natural products reported in peer-reviewed articles in 2016 in journals with good reputations were reviewed and analyzed. The advances that Asian research groups made in the field of natural products chemistry in 2016 were summarized. Compounds with unique structural features and/or promising bioactivities originating from Asian natural sources were discussed based on structural classification.

Isobenzofuranones and Isochromenones from the Deep-Sea Derived Fungus Leptosphaeria sp. SCSIO 41005

Four new isobenzofuranones, leptosphaerins J–M (1–4), including an unusual naturally-occurring centrosymmetric dimer skeleton (1), and two new isochromenones, clearanols I–J (9–10), were obtained from a culture of a deep-sea sediment-derived fungus Leptosphaeria sp. SCSIO 41005, together with four known isobenzofuranones (5–8) and six known isochromenones (11–16). These structures were elucidated by extensive spectroscopic analyses, and absolute configurations were assigned on the basis of electronic circular dichroism and optical rotations data comparison. Additionally, the absolute configurations of the new compounds 1 and 9, together with the known one 7 with stereochemistry undetermined, were further confirmed by single crystal X-ray diffraction experiments. A plausible biosynthetic pathway of these isobenzofuranones and isochromenones was also proposed.