Structurally Diverse Polyketides From the Mangrove-Derived Fungus Diaporthe sp. SCSIO 41011 With Their Anti-influenza A Virus Activities

Diaporpyrone E, an undescribed α-pyrone from the endophytic fungus Diaporthe sp. CB10100

An undescribed α-pyrone diaporpyrone E (1), and three known nucleotides, 5'-O-acetyl uridine (2), 5'-O-acetyl thymidine (3), and adenine (4), were identified from Diaporthe sp. CB10100, an endophytic fungus isolated from the medicinal plant Sinomenium acutum. The structure of 1 was determined by extensive analysis of its HRMS, 1D and 2D NMR spectroscopic data, as well as electronic circular dichroism calculations and comparison. The in vitro cytotoxic and antibacterial assays of 1 revealed that it has a 30.2% inhibitory effect on HepG2 cells at 50 μM, while no antibacterial activities against Staphylococcus aureus and Klebsiella pneumoniae at 64 μg/mL.

Two New Isocoumarins Isolated from the Marine-Sponge-Derived Fungus Setosphaeria sp. SCSIO41009

Two new dihydroisocoumarins, exserolides L and M (1 and 2), along with six known compounds (3-8) were isolated from the extract of the marine-sponge-derived fungus Setosphaeria sp. SCSIO41009. Their structures were established by spectroscopic analyses. The absolute configurations of two new compounds were determined by modified Mosher's method and ECD data. Compounds 1 and 4 showed significant antiviral activities against A/Puerto Rico/8/34 H274Y (H1 N1) with IC50 values of 4.07±0.76 μM and 20.06±4.85 μM, respectively.

Screening Marine Microbial Metabolites as Promising Inhibitors of Borrelia garinii: A Structural Docking Approach towards Developing Novel Lyme Disease Treatment

Lyme disease caused by the Borrelia species is a growing health concern in many parts of the world. Current treatments for the disease may have side effects, and there is also a need for new therapies that can selectively target the bacteria. Pathogens responsible for Lyme disease include B. burgdorferi, B. afzelii, and B. garinii. In this study, we employed structural docking-based screening to identify potential lead-like inhibitors against the bacterium. We first identified the core essential genome fraction of the bacterium, using 37 strains. Later, we screened a library of lead-like marine microbial metabolites (n = 4730) against the arginine deiminase (ADI) protein of Borrelia garinii. This protein plays a crucial role in the survival of the bacteria, and inhibiting it can kill the bacterium. The prioritized lead compounds demonstrating favorable binding energies and interactions with the active site of ADI were then evaluated for their drug-like and pharmacokinetic parameters to assess their suitability for development as drugs. Results from molecular dynamics simulation (100 ns) and other scoring parameters suggest that the compound CMNPD18759 (common name: aureobasidin; IUPAC name: 2-[(4R,6R)-4,6-dihydroxydecanoyl]oxypropan-2-yl (3S,5R)-3,5-dihydroxydecanoate) holds promise as a potential drug candidate for the treatment of Lyme disease, caused by B. garinii. However, further experimental studies are needed to validate the efficacy and safety of this compound in vivo.

Comparative metabolomic study of fungal foliar endophytes and their long-lived host Astrocaryum sciophilum: a model for exploring the chemodiversity of host-microbe interactions

Introduction

In contrast to the dynamics observed in plant/pathogen interactions, endophytic fungi have the capacity to establish enduring associations within their hosts, leading to the development of a mutually beneficial relationship that relies on specialized chemical interactions. Research indicates that the presence of endophytic fungi has the ability to significantly modify the chemical makeup of the host organism. Our hypothesis proposes the existence of a reciprocal exchange of chemical signals between plants and fungi, facilitated by specialized chemical processes that could potentially manifest within the tissues of the host. This research aimed to precisely quantify the portion of the cumulative fungal endophytic community's metabolome detectable within host leaves, and tentatively evaluate its relevance to the host-endophyte interplay. The understory palm Astrocaryum sciophilum (Miq.) Pulle was used as a interesting host plant because of its notable resilience and prolonged life cycle, in a tropical ecosystem.

Method

Using advanced metabolome characterization, including UHPLC-HRMS/MS and molecular networking, the study explored enriched metabolomes of both host leaves and 15 endophytic fungi. The intention was to capture a metabolomic "snapshot" of both host and endophytic community, to achieve a thorough and detailed analysis.

Results and discussion

This approach yielded an extended MS-based molecular network, integrating diverse metadata for identifying host- and endophyte-derived metabolites. The exploration of such data (>24000 features in positive ionization mode) enabled effective metabolome comparison, yielding insights into cultivable endophyte chemodiversity and occurrence of common metabolites between the holobiont and its fungal communities. Surprisingly, a minor subset of features overlapped between host leaf and fungal samples despite significant plant metabolome enrichment. This indicated that fungal metabolic signatures produced in vitro remain sparingly detectable in the leaf. Several classes of primary metabolites were possibly shared. Specific fungal metabolites and/or compounds of their chemical classes were only occasionally discernible in the leaf, highlighting endophytes partial contribution to the overall holobiont metabolome. To our knowledge, the metabolomic study of a plant host and its microbiome has rarely been performed in such a comprehensive manner. The general analytical strategy proposed in this paper seems well-adapted for any study in the field of microbial- or microbiome-related MS and can be applied to most host-microbe interactions.

Potential of Secondary Metabolites of Diaporthe Species Associated with Terrestrial and Marine Origins

Diaporthe species produce versatile secondary metabolites (SMs), including terpenoids, fatty acids, polyketides, steroids, and alkaloids. These structurally diverse SMs exhibit a wide range of biological activities, including cytotoxic, antifungal, antibacterial, antiviral, antioxidant, anti-inflammatory, and phytotoxic activities, which could be exploited in the medical, agricultural, and other modern industries. This review comprehensively covers the production and biological potencies of isolated natural products from the genus Diaporthe associated with terrestrial and marine origins. A total of 275 SMs have been summarized from terrestrial (153; 55%) and marine (110; 41%) origins during the last twelve years, and 12 (4%) compounds are common to both environments. All secondary metabolites are categorized predominantly on the basis of their bioactivities (cytotoxic, antibacterial, antifungal, and miscellaneous activity). Overall, 134 bioactive compounds were isolated from terrestrial (92; 55%) and marine (42; 34%) origins, but about half the compounds did not report any kind of activity. The antiSMASH results suggested that Diaporthe strains are capable of encoding a wide range of SMs and have tremendous biosynthetic potential for new SMs. This study will be useful for future research on drug discovery from terrestrial and marine natural products.

Chemical Investigation of Endophytic Diaporthe unshiuensis YSP3 Reveals New Antibacterial and Cytotoxic Agents

Chemical investigation of the plant-derived endophytic fungus Diaporthe unshiuensis YSP3 led to the isolation of four new compounds (1-4), including two new xanthones (phomopthane A and B, 1 and 2), one new alternariol methyl ether derivative (3) and one α-pyrone derivative (phomopyrone B, 4), together with eight known compounds (5-12). The structures of new compounds were interpreted on the basis of spectroscopic data and single-crystal X-ray diffraction analysis. All new compounds were assessed for their antimicrobial and cytotoxic potential. Compound 1 showed cytotoxic activity against HeLa and MCF-7 cells with IC₅₀ values of 5.92 µM and 7.50 µM, respectively, while compound 3 has an antibacterial effect on Bacillus subtilis (MIC value 16 μg/mL).

Antiviral Potential of Natural Resources against Influenza Virus Infections

Influenza is a severe contagious disease caused by influenza A and B viruses. The WHO estimates that annual outbreaks lead to 3-5 million severe infections of which approximately 10% lead to the death of the patient. While vaccination is the cornerstone of prevention, antiviral drugs represent the most important treatment option of acute infections. Only two classes of drugs are currently approved for the treatment of influenza in numerous countries: M2 channel blockers and neuraminidase inhibitors. In some countries, additional compounds such as the recently developed cap-dependent endonuclease inhibitor baloxavir marboxil or the polymerase inhibitor favipiravir are available. However, many of these compounds suffer from poor efficacy, if not applied early after infection. Furthermore, many influenza strains have developed resistances and lost susceptibility to these compounds. As a result, there is an urgent need to develop new anti-influenza drugs against a broad spectrum of subtypes. Natural products have made an important contribution to the development of new lead structures, particularly in the field of infectious diseases. Therefore, this article aims to review the research on the identification of novel lead structures isolated from natural resources suitable to treat influenza infections.

Microbial Natural Products with Antiviral Activities, Including Anti-SARS-CoV-2: A Review

The SARS-CoV-2 virus, which caused the COVID-19 infection, was discovered two and a half years ago. It caused a global pandemic, resulting in millions of deaths and substantial damage to the worldwide economy. Currently, only a few vaccines and antiviral drugs are available to combat SARS-CoV-2. However, there has been an increase in virus-related research, including exploring new drugs and their repurposing. Since discovering penicillin, natural products, particularly those derived from microbes, have been viewed as an abundant source of lead compounds for drug discovery. These compounds treat bacterial, fungal, parasitic, and viral infections. This review incorporates evidence from the available research publications on isolated and identified natural products derived from microbes with anti-hepatitis, anti-herpes simplex, anti-HIV, anti-influenza, anti-respiratory syncytial virus, and anti-SARS-CoV-2 properties. About 131 compounds with in vitro antiviral activity and 1 compound with both in vitro and in vivo activity have been isolated from microorganisms, and the mechanism of action for some of these compounds has been described. Recent reports have shown that natural products produced by the microbes, such as aurasperone A, neochinulin A and B, and aspulvinone D, M, and R, have potent in vitro anti-SARS-CoV-2 activity, targeting the main protease (Mpro). In the near and distant future, these molecules could be used to develop antiviral drugs for treating infections and preventing the spread of disease.

Endophytic Fungi as a Source of Antiviral Compounds - A Review

Endophytic fungi are a rich source of secondary metabolites. The interactions between endophytes and their hosts lead to the production of several bioactive substances grouped into different classes, each having a wide variety of effects against various pathogens. The metabolites obtained from these organisms include steroids, alkaloids, phenols, isocoumarins, xanthones, quinones, and terpenoids, among others. These substances are known to have antibiotic, antiparasitic, antifungal, and antiviral effects. This review summarizes secondary metabolites with antiviral effects produced by endophytic fungi and highlights the importance of research in developing novel antiviral substances. We demonstrate that endophytic fungi are a rich source of secondary metabolites that combat pathologies caused by viruses. Optimizing practical and biotechnological screening tools for the research of these metabolites will provide promising drugs to combat these infections.

Recent advances in natural phthalides: Distribution, chemistry, and biological activities

Phthalides, an important class of bioactive natural products, are widely distributed in plants, fungi, lichens, and liverworts. Amon them, n-butylphthalide, a phthalide monomer, has been approved to cure ischemic stroke. Owing to their good bioactivities in anti-microbial, anti-inflammatory, anti-tumor, anti-diabetic, and other aspects, a large number of researches have been conducted on phthalides from nature materials. In recent years, hundreds of novel natural phthalides were obtained. This review provides profiles of the advances in the distribution, chemistry, and biological activities of natural phthalides in 2016-2022.

Marine-Derived Xanthone from 2010 to 2021: Isolation, Bioactivities and Total Synthesis

Marine life has proved to be an invaluable source of new compounds with significant bioactivities, such as xanthones. This review summarizes the advances made in the study of marine-derived xanthones from 2010 to 2021, from isolation towards synthesis, highlighting their biological activities. Most of these compounds were isolated from marine-derived fungi, found in marine sediments, and associated with other aquatic organisms (sponge and jellyfish). Once isolated, xanthones have been assessed for different bioactivities, such as antibacterial, antifungal, and cytotoxic properties. In the latter case, promising results have been demonstrated. Considering the significant bioactivities showed by xanthones, efforts have been made to synthesize these compounds, like yicathins B and C and the secalonic acid D, through total synthesis.

Bioactive Marine Xanthones: A Review

The marine environment is an important source of specialized metabolites with valuable biological activities. Xanthones are a relevant chemical class of specialized metabolites found in this environment due to their structural variety and their biological activities. In this work, a comprehensive literature review of marine xanthones reported up to now was performed. A large number of bioactive xanthone derivatives (169) were identified, and their structures, biological activities, and natural sources were described. To characterize the chemical space occupied by marine-derived xanthones, molecular descriptors were calculated. For the analysis of the molecular descriptors, the xanthone derivatives were grouped into five structural categories (simple, prenylated, O-heterocyclic, complex, and hydroxanthones) and six biological activities (antitumor, antibacterial, antidiabetic, antifungal, antiviral, and miscellaneous). Moreover, the natural product-likeness and the drug-likeness of marine xanthones were also assessed. Marine xanthone derivatives are rewarding bioactive compounds and constitute a promising starting point for the design of other novel bioactive molecules.

Secondary metabolites from mangrove-associated fungi: source, chemistry and bioactivities

Covering 1989 to 2020The mangrove forests are a complex ecosystem occurring at tropical and subtropical intertidal estuarine zones and nourish a diverse group of microorganisms including fungi, actinomycetes, bacteria, cyanobacteria, algae, and protozoa. Among the mangrove microbial community, mangrove associated fungi, as the second-largest ecological group of the marine fungi, not only play an essential role in creating and maintaining this biosphere but also represent a rich source of structurally unique and diverse bioactive secondary metabolites, attracting significant attention of organic chemists and pharmacologists. This review summarizes the discovery relating to the source and characteristics of metabolic products isolated from mangrove-associated fungi over the past thirty years (1989-2020). Its emphasis included 1387 new metabolites from 451 papers, focusing on bioactivity and the unique chemical diversity of these natural products.

Chromone Derivatives with α-Glucosidase Inhibitory Activity from the Marine Fungus Penicillium thomii Maire

The fungal strain YPGA3 was isolated from the sediments of the Yap Trench and identified as Penicillium thomii. Eight new chromone derivatives, named penithochromones M-T (1-8), along with two known analogues, 9 and 10, were isolated from the strain. The structures were established by detailed analyses of the spectroscopic data. The absolute configuration of the only chiral center in compound 1 was tentatively determined by comparing the experimental and the calculated specific rotations. Compounds 7 and 8 represent the first examples of chromone derivatives featuring a 5,7-dioxygenated chromone moiety with a 9-carbon side chain. Bioassay study revealed that compounds 6-10 exhibited remarkable inhibition against α-glucosidase with IC₅₀ values ranging from 268 to 1017 μM, which are more active than the positive control acarbose (1.3 mmol).

Marine Natural Products as a Source of Drug Leads against Respiratory Viruses: Structural and Bioactive Diversity

Respiratory viruses, including influenza virus, respiratory syncytial virus, coronavirus, etc., have seriously threatened the human health. For example, the outbreak of severe acute respiratory syndrome coronavirus, SARS, affected a large number of countries around the world. Marine organisms, which could produce secondary metabolites with novel structures and abundant biological activities, are an important source for seeking effective drugs against respiratory viruses. This report reviews marine natural products with activities against respiratory viruses, the emphasis of which was put on structures and antiviral activities of these natural products. This review has described 167 marinederived secondary metabolites with activities against respiratory viruses published from 1981 to 2019. Altogether 102 references are cited in this review article.

Bioactive Compounds from Mangrove Endophytic Fungus and Their Uses for Microorganism Control

Mangroves are ecosystems with unique characteristics due to the high salinity and amount of organic matter that house a rich biodiversity. Fungi have aroused much interest as they are an important natural source for the discovery of new bioactive compounds, with potential biotechnological and pharmacological interest. This review aims to highlight endophytic fungi isolated from mangrove plant species and the isolated bioactive compounds and their bioactivity against protozoa, bacteria and pathogenic viruses. Knowledge about this type of ecosystem is of great relevance for its preservation and as a source of new molecules for the control of pathogens that may be of importance for human, animal and environmental health.

Marine endophytic fungi associated with Halopteris scoparia (Linnaeus) Sauvageau as producers of bioactive secondary metabolites with potential dermocosmetic application

Marine fungi and, particularly, endophytic species have been recognised as one of the most prolific sources of structurally new and diverse bioactive secondary metabolites with multiple biotechnological applications. Despite the increasing number of bioprospecting studies, very few have already evaluated the cosmeceutical potential of marine fungal compounds. Thus, this study focused on a frequent seaweed in the Portuguese coast, Halopteris scoparia, to identify the endophytic marine fungi associated with this host, and assess their ability to biosynthesise secondary metabolites with antioxidative, enzymatic inhibitory (hyaluronidase, collagenase, elastase and tyrosinase), anti-inflammatory, photoprotective, and antimicrobial (Cutibacterium acnes, Staphylococcus epidermidis and Malassezia furfur) activities. The results revealed eight fungal taxa included in the Ascomycota, and in the most representative taxonomic classes in marine ecosystems (Eurotiomycetes, Sordariomycetes and Dothideomycetes). These fungi were reported for the first time in Portugal and in association with H. scoparia, as far as it is known. The screening analyses showed that most of these endophytic fungi were producers of compounds with relevant biological activities, though those biosynthesised by Penicillium sect. Exilicaulis and Aspergillus chevalieri proved to be the most promising ones for being further exploited by dermocosmetic industry. The chemical analysis of the crude extract from an isolate of A. chevalieri revealed the presence of two bioactive compounds, echinulin and neoechinulin A, which might explain the high antioxidant and UV photoprotective capacities exhibited by the extract. These noteworthy results emphasised the importance of screening the secondary metabolites produced by these marine endophytic fungal strains for other potential bioactivities, and the relevance of investing more efforts in understanding the ecology of halo/osmotolerant fungi.

Intestinal mycobiota in health and diseases: from a disrupted equilibrium to clinical opportunities

Bacteria, viruses, protozoa, and fungi establish a complex ecosystem in the gut. Like other microbiota, gut mycobiota plays an indispensable role in modulating intestinal physiology. Notably, the most striking characteristics of intestinal fungi are their extraintestinal functions. Here, we provide a comprehensive review of the importance of gut fungi in the regulation of intestinal, pulmonary, hepatic, renal, pancreatic, and brain functions, and we present possible opportunities for the application of gut mycobiota to alleviate/treat human diseases. Video Abstract.

Marine natural products

This review covers the literature published between January and December in 2018 for marine natural products (MNPs), with 717 citations (706 for the period January to December 2018) 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 (1554 in 469 papers for 2018), 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. The proportion of MNPs assigned absolute configuration over the last decade is also surveyed.

Bioactive Secondary Metabolites of the Genus Diaporthe and Anamorph Phomopsis from Terrestrial and Marine Habitats and Endophytes: 2010-2019

The genus Diaporthe and its anamorph Phomopsis are distributed worldwide in many ecosystems. They are regarded as potential sources for producing diverse bioactive metabolites. Most species are attributed to plant pathogens, non-pathogenic endophytes, or saprobes in terrestrial host plants. They colonize in the early parasitic tissue of plants, provide a variety of nutrients in the cycle of parasitism and saprophytism, and participate in the basic metabolic process of plants. In the past ten years, many studies have been focused on the discovery of new species and biological secondary metabolites from this genus. In this review, we summarize a total of 335 bioactive secondary metabolites isolated from 26 known species and various unidentified species of Diaporthe and Phomopsis during 2010-2019. Overall, there are 106 bioactive compounds derived from Diaporthe and 246 from Phomopsis, while 17 compounds are found in both of them. They are classified into polyketides, terpenoids, steroids, macrolides, ten-membered lactones, alkaloids, flavonoids, and fatty acids. Polyketides constitute the main chemical population, accounting for 64%. Meanwhile, their bioactivities mainly involve cytotoxic, antifungal, antibacterial, antiviral, antioxidant, anti-inflammatory, anti-algae, phytotoxic, and enzyme inhibitory activities. Diaporthe and Phomopsis exhibit their potent talents in the discovery of small molecules for drug candidates.

Marine microorganisms as an untapped source of bioactive compounds

The search for novel biologically active molecules has extended to the screening of organisms associated with less explored environments. In this sense, Oceans, which cover nearly the 67% of the globe, are interesting ecosystems characterized by a high biodiversity that is worth being explored. As such, marine microorganisms are highly interesting as promising sources of new bioactive compounds of potential value to humans. Some of these microorganisms are able to survive in extreme marine environments and, as a result, they produce complex molecules with unique biological interesting properties for a wide variety of industrial and biotechnological applications. Thus, different marine microorganisms (fungi, myxomycetes, bacteria, and microalgae) producing compounds with antioxidant, antibacterial, apoptotic, antitumoral and antiviral activities have been already isolated. This review compiles and discusses the discovery of bioactive molecules from marine microorganisms reported from 2018 onwards. Moreover, it highlights the huge potential of marine microorganisms for obtaining highly valuable bioactive compounds.

Ultrathin interfacial modification of Li-rich layered oxide electrode/sulfide solid electrolyte via atomic layer deposition for high electrochemical performance batteries

Herein, Li-rich layered oxides (LLOs) are modified by sulfide solid electrolyte Li₁₀GeP₂S₁₂ (LGPS) with high ionic conductivity to enhance the diffusion of Li⁺ and an ultrathin Al₂O₃ layer is interposed between LLOs and LGPS through the atomic layer deposition (ALD) technique to inhibit the development of the highly resistive space-charge layer, the side reactions and structure transition of the composites, thus excellently promoting the electrochemical properties of the composites in liquid electrolyte. Among the different ALD cycles of Al₂O₃, 10 cycles of ultrathin Al₂O₃ layer achieves the greatest electrochemical performance. The beginning discharge capacity of LLOs@Al₂O₃/LGPS composites comes up to 233.4 mA h g^-1 with a capacity retention of 90.6% and a voltage retention of 97.3% after 100 cycles at 0.2 C. The composites also exhibit the optimal rate capability and a high energy density of 581 Wh kg^-1 at 1 C. The galvanostatic intermittent titration technique test indicates that the composites (LLOs@Al₂O₃/LGPS) possess the greatest Li⁺ diffusion coefficient (1.58 × 10^-10 cm² s^-1) compared to LLOs (0.85 × 10^-10 cm² s^-1) and LLOs/LGPS (1.10 × 10^-10 cm² s^-1). More importantly, charge curves at the beginning of the initial charge and electrochemical impedance spectroscopy curves clearly reveal the inhibition of the development of the highly resistive space-charge layer.

Cytotoxic benzopyranone and xanthone derivatives from a coral symbiotic fungus Cladosporium halotolerans GXIMD 02502

Coral-derived microorganisms have been historically proven to be prolific sources of bioactive secondary metabolites. Twelve benzopyranone and/or xanthone derivatives, including a new benzopyranone with an uncommon carboxyl group at C-8, coniochaetone K (1), were obtained from the Beibu Gulf-derived coral symbiotic fungus Cladosporium halotolerans GXIMD 02502. Their structures were determined by extensive spectroscopic data interpretation and comparison with literature values. The absolute configuration of 1 was accomplished by comparison of specific optical rotation as well as quantum chemical ECD calculations. The in vitro cytotoxicity of compounds 1-12 against two human prostatic cancer cell lines, C4-2B and 22RV1, were evaluated. And compounds 1, 3, 6-8, and 10-11 demonstrated significant cytotoxicity with inhibitions ranging from 55.8% to 82.1% at the concentration of 10 μM.

Antimicrobial drimane - phthalide derivatives from Hypoxylon fendleri BCC32408

Fourteen new compounds including thirteen drimane - phthalide derivatives (fendlerals A - C, fendlerins A - D, fendlerols A - B, fendleric acids A - C, fendlerinine G) and one terphenyl derivative (fendleryl E) along with eight known compounds, fendlerinine A, rickenyls C - D, fendleryls C - D, atromentin, tetramethyl atromentin, and (±)-microsphaerophthalide F, were isolated from the wood fungus Hypoxylon fendleri BCC32408. Compared with the prior work, the results indicated the agitation effect on the production of bioactive drimane - phthalides. The chemical structures were determined based upon spectroscopic analyses and the absolute configurations were verified by comparison of the ECD spectral data with the calculated ECD spectra of the related compounds. Compounds 1-3 exhibited antimicrobial activity against Plasmodium falciparum (IC₅₀ 4.15-4.39 μM), Colletotrichum capsici (MIC 6.25-12.5 μg/mL), and Bacillus cereus (MIC 1.56-3.13 μg/mL). All tested compounds displayed broad cytotoxicity against cancerous (MCF-7, KB, and NCI-H187) and non-cancerous (Vero) cells.

Cytotoxic Polyketides from a Deep-Sea Sediment Derived Fungus Diaporthe phaseolorum FS431

Two new chromone-derived polyketides phaseolorins, G and H (1 and 2), and one new anthraquinone derivative, phaseolorin I (3), together with three known compounds (4-6), were isolated from the deep-sea sediment-derived fungus Diaporthe phaseolorum FS431. The structures of the new compounds were determined by comprehensive analysis of their spectroscopic data, and the absolute configuration of 1 was established by quantum chemical calculations of electron capture detection (ECD). All the isolated compounds (1-6) were tested for their in vitro cytotoxic activities against four human tumor cell lines, of which compound 4 exhibited significant effect against MCF-7, HepG-2, and A549 tumor cell lines with IC50 values of 2.60, 2.55, and 4.64 µM, respectively.

Chromone derivatives, R- and S- taeniolin, from the marine-derived fungus Taeniolella sp. BCC31839

Two unknown enantiomeric compounds, named (R)- and (S)-taeniolin, along with six known compounds, were isolated from the marine-associated fungus Taeniolella sp. BCC31839. Chemical structures were determined by NMR spectroscopic techniques, and the absolute configurations were confirmed by Mosher application together with CD spectral analyses. Both were inactive for antimicrobial activity against multidrug-resistant malaria parasite (Plasmodium falciparum) and bacteria (Mycobacerium tuberculosis and Bacillus cereus) at maximum tested concentration.

Sesquiterpenoids and meroterpenoids from a mangrove derived fungus Diaporthe sp. SCSIO 41011

One new sesquiterpenoid, 1-methoxypestabacillin B (1), along with one known sesquiterpenoid (2) and six known chrodrimanin-type meroterpenoids (3‒8) were obtained from the solid cultures of a mangrove endophytic fungus Diaporthe sp. SCSIO 41011. Their structures including the absolute configuration at C-6 of compound 1, were determined by extensive spectroscopic analyses and ECD calculations. Meanwhile, the X-ray crystal structures and absolute configurations of two previously reported chrodrimanins E (3) and H (6), are described for the first time. All the compounds were examined for HIV latency-reversal and anti-influenza A virus activities.

Investigational antiviral therapies for the treatment of influenza

INTRODUCTION

Influenza viral ribonucleoprotein complexes (vRNPs) play a key role in viral transcription and replication; hence, the recent development of novel anti-influenza drugs targeting vRNPs has garnered widespread interest.

AREAS COVERED

We discuss the function of the constituents of vRNPs and summarize those vRNPs-targeted synthetic drugs that are in preclinical and early clinical development.

EXPERT OPINION

vRNPs contain high-value drug targets; such targets include the subunits PA, PB1, PB2, and NP. Developing a new generation of antiviral therapies with strategies that utilize existing drugs, natural compounds originated from new resources and novel drug combinations may open up new therapeutic approaches to influenza.

Structures, Activities and Drug-Likeness of Anti-Infective Xanthone Derivatives Isolated from the Marine Environment: A Review

Marine organisms represent almost half of total biodiversity and are a very important source of new bioactive substances. Within the varied biological activities found in marine products, their antimicrobial activity is one of the most relevant. Infectious diseases are responsible for high levels of morbidity and mortality and many antimicrobials lose their effectiveness with time due to the development of resistance. These facts justify the high importance of finding new, effective and safe anti-infective agents. Among the variety of biological activities of marine xanthone derivatives, one that must be highlighted is their anti-infective properties. In this work, a literature review of marine xanthones with anti-infective activity, namely antibacterial, antifungal, antiparasitic and antiviral, is presented. Their structures, biological activity, sources and the methods used for bioactivity evaluation are described. The xanthone derivatives are grouped in three sets: xanthones, hydroxanthones and glycosylated derivatives. Moreover, molecular descriptors, biophysico-chemical properties, and pharmacokinetic parameters were calculated, and the chemical space occupied by marine xanthone derivatives is recognized. The chemical space was compared with marketed drugs and framed accordingly to the drug-likeness concept in order to profile the pharmacokinetic of anti-infective marine xanthone derivatives.