Synthesis and Bioactivity of Ancorinoside B, a Marine Diglycosyl Tetramic Acid.

The sponge metabolite ancorinoside B was prepared for the first time in 16 steps and 4% yield. It features a β-d-galactopyranosyl-(1→4)-β-d-glucuronic acid tethered to a d-aspartic acid-derived tetramic acid. Key steps were the synthesis of a fully protected d-lactose derived thioglycoside, its attachment to a C-aldehyde spacer, functionalization of the latter with a terminal -(β-ketoacyl)-d-aspartate, and a basic Dieckmann cyclization to close the pyrrolidin-2,4-dione ring with concomitant global deprotection.

Synthesis and Bioactivity of a Macrocidin B Stereoisomer.

A stereoisomer of macrocidin B, a presumed metabolite of the fungus , was synthesized in 18 steps and 2.7% yield from protected l-tyrosine that was -β-ketoacylated with a fully functionalized octanoyl Meldrum's acid. Dieckmann condensation gave a 3-acyltetramic acid, which was macrocyclized via Williamson etherification between the phenol and -bromohydrin termini.

The Lytic Siphophage vB_StyS-LmqsSP1 Reduces the Number of Salmonella enterica Serovar Typhimurium Isolates on Chicken Skin.

Phage-based biocontrol of bacteria is considered a natural approach to combat foodborne pathogens. Salmonella spp. are notifiable and highly prevalent pathogens that cause foodborne diseases worldwide.

: more than a node or a foot-shaped basal cell.

Recent publications have argued that there are potentially serious consequences for researchers in recognising distinct genera in the terminal fusarioid clade of the family . Thus, an alternate hypothesis, namely a very broad concept of the genus was proposed. In doing so, however, a significant body of data that supports distinct genera in based on morphology, biology, and phylogeny is disregarded.

Dual Agents: Fungal Macrocidins and Synthetic Analogues with Herbicidal and Antibiofilm Activities.

Eight analogues of the bioherbicides macrocidin A () and Z () with structural variance in the size of the macrocycle, its - or -cyclophane character, and its functional groups were synthesized on two modular routes and tested for herbicidal, antibiotic, and antibiofilm activities. Apart from the lead compounds and , the structurally simplified dihydromacrocidin Z () and normacrocidin Z () showed high herbicidal activity in either thistles, dandelions or in both. The derivatives , , and dibromide also inhibited the growth of biofilms by ca 70% when applied at subtoxic concentrations as low as ca 20 µM, which are unlikely to induce bacterial resistance.

Five Tetramic Acid Derivatives Isolated from the Iranian Fungus CCTU A372.

Submerged mycelial cultures of the ascomycete   CCTU A372 were found to produce five previously undescribed tetramic acids, for which we propose the trivial names colposetins A-C (-) and colpomenoic acids A and B ( and ), along with the known compounds penicillide () and monodictyphenone (). The planar structures of - were determined by high-resolution electrospray ionization mass spectrometry (HR-ESIMS) and extensive 1D and 2D nuclear magnetic resonance (NMR) spectroscopy. Their absolute configurations were determined by the combination of electronic circular dischroism (ECD) analysis, -based configurational analysis, and a rotating-frame Overhauser effect spectroscopy (ROESY) experiment.

Synthesis of the fungal macrolide berkeleylactone A and its inhibition of microbial biofilm formation.

The fungal macrolide berkeleylactone A was synthesised in 13 steps and 24% yield using (R)-propylene oxide and an asymmetric Noyori hydrogenation of a β-ketoester to install the stereogenic centres. A domino addition-Wittig olefination of a 13-hydroxytetradecanal intermediate with the cumulated ylide Ph3PCCO closed the macrocyle by establishing the α,β-unsaturated ester group, necessary for the attachment of the sidechain thiol via a thia-Michael reaction. The synthetic berkeleylactone A inhibited the formation of Staphylococcus aureus biofilms and showed significant dispersive effects on preformed biofilms of Candida albicans by at least 45% relative to untreated controls at concentrations as low as 1.

Amycolatomycins A and B, Cyclic Hexapeptides Isolated from an sp. 195334CR.

The rare actinobacterium sp. strain 195334CR was found to produce previously undescribed cyclic hexapeptides, which we named amycolatomycin A and B ( and ). Their planar structures were determined by high-resolution mass spectrometry as well as extensive 1D and 2D NMR spectroscopy, while the absolute stereochemistry of its amino acids were determined by Marfey's method.

Three New Derivatives of Zopfinol from gen. et comb. nov.

was analyzed for the production of secondary metabolites, resulting in the isolation of known zopfinol () and its new derivatives zopfinol B-C (), the 10-membered lactones 7-O-acetylmultiplolide A () and 8-O-acetylmultiplolide A (), together with sordarin (), sordarin B (), and hypoxysordarin (). The absolute configuration of was elucidated by the synthesis of MPTA-esters. Compound showed antimicrobial activity against the Gram-positive bacteria and and the fungus .

Resolution of the Complex (Hypoxylaceae, Xylariales) and Discovery and Biological Characterization of Two of Its Prominent Secondary Metabolites.

a large, cosmopolitan genus of Ascomycota is in the focus of our current poly-thetic taxonomic studies, and served as an excellent source for bioactive secondary metabolites at the same time. The present work concerns a survey of the species complex based on specimens from Iran and Europe by morphological studies and high performance liquid chromatography coupled to mass spectrometry and diode array detection (HPLC-MS-DAD). Apart from known chemotaxonomic markers like binaphthalene tetrol (BNT) and daldinin F, two unprece-dented molecules were detected and subsequently isolated to purity by semi preparative HPLC.

Diversity of Isolated from Date Palms Rhizosphere and Saline Environments: Isolation, Identification and Biological Activity Evaluation.

The diversity of cultural in two types of Algerian Sahara environments, including saline environments and date palms rhizosphere, was investigated. In this study, a total of 40 strains of actinomycetes was isolated from different soil samples, using a rehydration and centrifugation method. Molecular identification, based on 16S rRNA gene sequence analysis, revealed that these isolates were affiliated to six clusters corresponding to eight genera, including , and .

Macrooxazoles A-D, New 2,5-Disubstituted Oxazole-4-Carboxylic Acid Derivatives from the Plant Pathogenic Fungus .

In our ongoing search for new bioactive fungal metabolites, four previously undescribed oxazole carboxylic acid derivatives (-) for which we proposed the trivial names macrooxazoles A-D together with two known tetramic acids (-) were isolated from the plant pathogenic fungus . Their structures were elucidated based on high-resolution mass spectrometry (HR-MS) and nuclear magnetic resonance (NMR) spectroscopy. The hitherto unclear structure of macrocidin Z () was also confirmed by its first total synthesis.

Recent progress in biodiversity research on the Xylariales and their secondary metabolism.

The families Xylariaceae and Hypoxylaceae (Xylariales, Ascomycota) represent one of the most prolific lineages of secondary metabolite producers. Like many other fungal taxa, they exhibit their highest diversity in the tropics. The stromata as well as the mycelial cultures of these fungi (the latter of which are frequently being isolated as endophytes of seed plants) have given rise to the discovery of many unprecedented secondary metabolites.

Erinacine C Activates Transcription from a Consensus ETS DNA Binding Site in Astrocytic Cells in Addition to NGF Induction.

Medicinal mushrooms of the genus are known to produce secondary metabolites with homeostatic properties for the central nervous system. We and others have recently demonstrated that among these metabolites cyathane diterpenoids and in particular erinacine C possess potent neurotrophin inducing properties in astrocytic cells. Yet, the signaling events downstream of erinacine C induced neurotrophin acitivity in neural-like adrenal phaeochromocytoma cells (PC12) cells have remained elusive.

Isolation and identification of Streptomyces sp. Act4Zk, a good producer of Staurosporine and some derivatives.

In this study, strain Streptomyces sp. Act4Zk was isolated based on a method developed for the isolation of myxobacteria. Due to the low efficiency of the majority of conventional DNA extraction techniques, for molecular identification of the strain Streptomyces sp.

Special Issue: "Actinobacteria and Myxobacteria-Important Resources for Novel Antibiotics".

The history of our antibiotics is inseparably connected to microorganisms as producers [...

Phylogenetic Assignment of the Fungicolous (Ascomycota, Xylariales) and Investigation of its Secondary Metabolites.

The ascomycete was described in 2014 as a fungicolous species growing on a member of its own genus, , which is considered a rare lifestyle in the Hypoxylaceae. This renders an interesting target in our efforts to find new bioactive secondary metabolites from members of the Xylariales. So far, only volatile organic compounds have been reported from , but no investigation of non-volatile compounds had been conducted.

Phylogenetic and Chemotaxonomic Studies Confirm the Affinities of to the Coprophilous Xylariaceae.

The genus was erected in 1973 by Jong and Davis to accommodate the pyrophilic pyrenomycete and has traditionally been placed in the family Xylariaceae based on morphological features. However, no living culture of this genus has so far been available in the public domain. Molecular data were restricted to an internal transcribed spacer (ITS) sequence that only confirmed the familial position, and was generated from a strain that is not deposited in a public culture collection.

Hybridorubrins A-D: Azaphilone Heterodimers from Stromata of Hypoxylon fragiforme and Insights into the Biosynthetic Machinery for Azaphilone Diversification.

The diversity of azaphilones in stromatal extracts of the fungus Hypoxylon fragiforme was investigated and linked to their biosynthetic machineries by using bioinformatics. Nineteen azaphilone-type compounds were isolated and characterized by NMR spectroscopy and mass spectrometry, and their absolute stereoconfigurations were assigned by using Mosher ester analysis and electronic circular dichroism spectroscopy. Four unprecedented bis-azaphilones, named hybridorubrins A-D, were elucidated, in addition to new fragirubrins F and G and various known mitorubrin derivatives.

Viridistratins A-C, Antimicrobial and Cytotoxic Benzo[]fluoranthenes from Stromata of (Hypoxylaceae, Ascomycota).

During the course of our search for novel biologically active metabolites from tropical fungi, we are using chemotaxonomic and taxonomic methodology for the preselection of interesting materials. Recently, three previously undescribed benzo[]fluoranthenes (-) together with the known derivatives truncatones A and C (, ) were isolated from the stromata of the recently described species collected in Thailand. Their chemical structures were elucidated by means of spectral methods, including nuclear magnetic resonance (NMR) spectroscopy and high-resolution mass spectrometry (HR-MS).

Nonocarbolines A-E, -Carboline Antibiotics Produced by the Rare Actinobacterium sp. from Indonesia.

During the course of our ongoing screening for novel biologically active secondary metabolites, the rare Actinobacterium, sp. 1808210CR was found to produce five unprecedented -carboline derivatives, nonocarbolines A-E (). Their structures were elucidated from high-resolution mass spectrometry, 1D and 2D nuclear magnetic resonance spectroscopy, and the absolute configuration of was determined by using the modified Mosher method.

Haprolid Inhibits Tumor Growth of Hepatocellular Carcinoma through Rb/E2F and Akt/mTOR Inhibition.

Background: Hepatocellular carcinoma (HCC) represents a major health burden with limited curative treatment options. There is a substantial unmet need to develop innovative approaches to impact the progression of advanced HCC. Haprolid is a novel natural component isolated from myxobacteria.

Diversity and Bioactive Potential of Actinobacteria from Unexplored Regions of Western Ghats, India.

The search for novel bioactive metabolites continues to be of much importance around the world for pharmaceutical, agricultural, and industrial applications. Actinobacteria constitute one of the extremely interesting groups of microorganisms widely used as important biological contributors for a wide range of novel secondary metabolites. This study focused on the assessment of antimicrobial and antioxidant activity of crude extracts of actinobacterial strains.

Pigmentosins from sp. as antibiofilm agents and a new glycosylated asperfuran from .

In the course of our exploration of the Thai invertebrate-pathogenic fungi for biologically active metabolites, pigmentosin A () and a new bis(naphtho-α-pyrone) derivative, pigmentosin B (), were isolated from the spider-associated fungus sp. Furthermore, a new glycosylated asperfuran , together with one new () and two known ( and ) cyclodepsipeptides, was isolated from . The pigmentosins and showed to be active against biofilm formation of DSM1104.

Antifungal Sesquiterpenoids, Rhodocoranes, from Submerged Cultures of the Wrinkled Peach Mushroom, .

Seven previously unknown sesquiterpenoids and norsesquiterpenoids, rhodocoranes F-L (-), were isolated from the fermentation broth of the basidiomycete . Their structures were elucidated utilizing 1D and 2D NMR techniques as well as HRESIMS; they are unusual noracorane, spiro[4.4]nonene, and acorane-type sesquiterpenoids.