Mansouramycins E-G, Cytotoxic Isoquinolinequinones from Marine Streptomycetes.

Chemical investigation of the ethyl acetate extract from the marine-derived sp. isolate B1848 resulted in three new isoquinolinequinone derivatives, the mansouramycins E-G (-), in addition to the previously reported mansouramycins A () and D (). Their structures were elucidated by computer-assisted interpretation of 1D and 2D NMR spectra, high-resolution mass spectrometry, and by comparison with related compounds.

Sulochrins and alkaloids from a fennel endophyte sp. FVL2.

The fungal endophyte sp. strain FVL2, isolated from the traditional medicinal fennel plant, , was investigated for secondary metabolites. Fermentation on rice medium followed by chromatographic separation delivered three new natural products, 7-demethyl-neosulochrin (), fumigaclavine I () and -benzoyl-tryptophan () together with further 14 known metabolites, 1--methyl-sulochrin-4'-sulfate, questin, laccaic acid, isorhodoptilometrin, fumigaclavine A, fumigaclavine C, fumitremorgin C, fumigaquinazoline C, tryptoquivaline J, trypacidin, 3'--demethyl-sulochrin, 1--methyl-sulochrin, protocatechuic acid, and vermelone.

New Haloterpenes from the Marine Red Alga : Structure Elucidation and Biological Activity.

Analysis of the air-dried marine red alga , collected near Ras-Bakr at the Suez gulf (Red Sea) in Egypt delivered five new halogenated terpene derivatives: aplysiolic acid (), 7-acetyl-aplysiol (), aplysiol-7-one (), 11,14-dihydroaplysia-5,11,14,15-tetrol (), and a new maneonene derivative , named 5--maneolactone. The chemical structures of these metabolites were characterized employing spectroscopic methods, and the relative and absolute configurations were determined by comparison of experimental and ab initio-calculated NMR, NOE, ECD, and ORD data, and by X-ray diffraction of and . The antimicrobial activities of the crude extract and compounds -, and were studied.

Boshramycinones A-C: New anthracyclinones produced by a marine-derived sp.: isolation, structure elucidation and biological activities.

Boshramycinones A-C (), three new anthracyclinones, were isolated from the culture broth of the marine-derived sp. Mei 16-1,2 together with 2-acetyl-1,8-dihydroxy-3-methyl-anthraquinone () and bafilomycins B1, B2, and C1-amide. The isolated compounds were identified by NMR spectroscopy and mass spectrometry, the absolute configuration of was determined by comparison of experimental and calculated chiroptical data.

Isolation, Synthesis And Structure Determination Of Cannabidiol Derivatives And Their Cytotoxic Activities.

In a continuing effort to explore the structural diversity and pharmacological activities of natural products based scaffolds, herein, we report the isolation, synthesis, and structure determination of cannabidiol and its derivatives along with their cytotoxic activities. Treatment of cannabidiol () with acid catalyst POCl afforded a new derivative along with six known molecules -, and, . The structure of was elucidated by extensive spectroscopic analyses and DFT calculations of the NMR and ECD data.

Karamomycins A-C: 2-Naphthalen-2-yl-thiazoles from Nonomuraea endophytica.

Karamomycins A-C (2-4), the first natural 2-naphthalen-2-yl-thiazole derivatives, were isolated along with a plausible precursor molecule, 1-hydroxy-4-methoxy-2-naphthoic acid (1), uracil, 1-acetyl-β-carboline, and actinomycin C2 from the culture broth of the terrestrial actinomycete strain GW58/450, identified as Nonomuraea endophytica. These compounds were characterized by analysis of their NMR and mass spectrometry (MS) data; the absolute configurations of 2 and 4 were determined by comparison of C NMR, NOESY, and circular dichroism (CD) spectra with density functional theory (DFT)-calculated data. In karamomycin C (4), the thiazole of 2 is connected to an unusual iminothiazolo[4,3- c][1,4]thiazepinone, for which we proposed a biosynthetic origin from two cysteine residues.

Rubescins F-H, new vilasinin-type limonoids from the leaves of Trichilia rubescens (Meliaceae).

Three new limonoids, designated as rubescins F (1), G (2), and H (3), together with two known compounds of this type, TS1 (4) and trichirubine A (5), were isolated from methylene chloride/methanol extracts of Trichilia rubescens leaves. The structures of these compounds were elucidated based on 1D and 2D nuclear magnetic resonance (NMR) analysis and complemented by electrospray ionization high-resolution mass spectrometry results and by comparison to data of related compounds described in the literature and ab initio calculations. Rubescin F (1) is the first limonoid from Trichilia spp.

Carbazole-, Aspidofractinine-, and Aspidocarpamine-Type Alkaloids from Pleiocarpa pycnantha.

Three new alkaloids, janetinine (1a), pleiokomenine A (2), and huncaniterine B (3a), and 13 known compounds, pleiomutinine (3b), huncaniterine A (3c), 1-carbomethoxy-β-carboline (4), evoxanthine (5), deformyltalbotine acid lactone (6), pleiocarpamine (7), N-methyl-10-hydroxygeissoschizol (8), spegatrine (9), neosarpagine (10), aspidofractinine (11), N-methylkopsinin (12), pleiocarpine (13), and N-methylkopsinin- N-oxide (14), were isolated from the stem bark of Pleiocarpa pycnantha. Janetinine (1a) is a carbazole alkaloid; in pleiokomenine A (2), two aspidofractinine-type alkaloids are bridged by a methylene unit in an unprecedented way, and huncaniterine B (3a) is a pleiocarpamine-aspidofractinine-type dimer. The structures and relative configurations of these compounds were elucidated on the basis of NMR and MS analyses.

Terretonin M: A new meroterpenoid from the thermophilic Aspergillus terreus TM8 and revision of the absolute configuration of penisimplicins.

Terretonin M (1), a new highly oxygenated tetracyclic meroterpenoid, was isolated from the thermophilic fungus Aspergillus terreus TM8 together with 10 known metabolites: terrelumamide A, asterrelenin, 7-prenyl-indolyl-3-carbaldehyde, (3β,5α,6β)-3,5,6-trihydroxy-ergosta-7,22-diene, sitostenone, linoleic acid, ergosterol, uracil, p-hydroxy-benzoic acid, and indole-3-carboxylic acid. The chemical structure of the new compound was elucidated by extensive 1D, 2D NMR, and ESI HR mass measurements, and by comparison with literature data. The absolute configuration of 1 was resolved by analysis of its NOESY spectrum and comparison of its experimental ECD spectrum with DFT calculations.

seco-Tiaminic acids B and C: Identification of two novel 3,4-seco-tirucallane triterpenoids isolated from the root of Entandrophragma congoënse (Meliaceae).

Chemical investigation of the roots of Entandrophragma congoënse (Meliaceae) led to the isolation of two new 3,4-seco-tirucallane triterpenes, namely seco-tiaminic acids B and C (1 and 2) together with nine known compounds: 3,4-secotirucalla-21-formyl-23-oxo-4(28),7,24-trien-3-oic acid (3), methyl angolensate (4), molucensin N (5), molucensin O (6), piscidinol A (7), 7α,20(S)-dihydroxy-4,24(28)-ergostadien-3-one (8), 24-methylene-cholest-5-en-3β,7α-diol (9), entilin A (10), and entilin B (11). Their structures were determined using extensive spectroscopic methods including 1D and 2D NMR, HRMS, and CD analyses; new results were compared to existing data in the literature. The two newly identified seco-tiaminic acids showed moderate antiplasmodial and cytotoxic activities against a chloroquine-sensitive strain of the malaria parasite (Plasmodium falciparum NF54) and were cytotoxic toward an L6 rat skeletal myoblast cell line, respectively.

Indoline alkaloids from Tabernaemontana contorta with cancer chemopreventive activity.

Two bisindoline alkaloids, contortarine A, 16-epi-pleiomutinine and a reaction product of pleiomutinine, namely N-chloromethyl-pleiomutinine, were isolated from the roots of Tabernaemontana contorta Stapf. together with five known compounds: pleiomutinine, 1-carbomethoxy-β-carboline, strictosidine lactam, pleiocarpamine, and pleiocarpine. The structures and relative configuration of these alkaloids were determined by extensive 1D and 2D NMR, and MS measurements.

New Azulene-Type Sesquiterpenoids from the Fruiting Bodies of Lactarius deliciosus.

In the H NMR-guided fractionation of extracts from the edible mushroom Lactarius deliciosus, two new azulene-type sesquiterpenoids, 7-isopropenyl-4-methyl-azulene-1-carboxylic acid (1) and 15-hydroxy-3,6-dihydrolactarazulene (2), together with seven known compounds were characterized. Their structures were determined on basis of spectroscopic evidence, as well as by comparing with literature data. Amongst the known metabolites, the C NMR assignment of 15-hydroxy-6,7-dihydrolactarazulene (3) is reported here for the first time.

Epigenetic Modulation of Endophytic Eupenicillium sp. LG41 by a Histone Deacetylase Inhibitor for Production of Decalin-Containing Compounds.

An endophytic fungus, Eupenicillium sp. LG41, isolated from the Chinese medicinal plant Xanthium sibiricum, was subjected to epigenetic modulation using an NAD-dependent histone deacetylase (HDAC) inhibitor, nicotinamide. Epigenetic stimulation of the endophyte led to enhanced production of two new decalin-containing compounds, eupenicinicols C and D (3 and 4), along with two biosynthetically related known compounds, eujavanicol A (1) and eupenicinicol A (2).

Isolation and Structural Elucidation of Nitrogenous Secondary vetabolites from Terrestrial and Marine Streptomyces spp.

Screening and chromatography of extracts from a terrestrial and a marine-derived streptomycete yielded two new nitrogenous benzene derivatives, namely (S)-N-[3-hydroxy--(4-hydroxyphenyl)-propyl]-acetamide (1a), and (R)-2-(l-methyl-2-oxopropylamino)-benzoic acid (2). Additionally, eight known compounds were. isolated, 2-acetamidophenol, phenazine-l-carboxylic acid, phenazine-l-carboxylic acid methyl ester, perlolyrin, tyrosol, uracil, and anthranilic acid.

Metabolites from the Endophytic Fungus Curvularia sp. M12 Act as Motility Inhibitors against Phytophthora capsici Zoospores.

The endophytic fungus Curvularia sp., strain M12, was isolated from a leaf of the medicinal plant Murraya koenigii and cultured on rice medium followed by chemical screening of the culture extract. Chromatographic analysis led to the isolation of four new compounds, murranofuran A (1), murranolide A (2), murranopyrone (3a), and murranoic acid A (4a), along with six known metabolites, N-(2-hydroxy-6-methoxyphenyl)acetamide (5), curvularin (6), (S)-dehydrocurvularin (7), pyrenolide A (8), modiolide A (9), and 8-hydroxy-6-methoxy-3-methylisocoumarin (10).

The structure of antrocarine E, an ergostane isolated from Antrocaryon klaineanum Pierre (Anacardiaceae).

Eight compounds were isolated from the stem bark of Antrocaryon klaineanum, and their structures determined by chemical and spectroscopic methods. Among these compounds, the ergostane-type antrocarine E (1a) is a new compound, although the structure had already been published by mismatching the spectroscopic data with those of 2. In this paper, we are reporting the valid spectroscopic values for antrocarine E and X-ray diffraction results.

Inhibitory Effects of Macrotetrolides from spp. On Zoosporogenesis and Motility of Peronosporomycete Zoospores Are Likely Linked with Enhanced ATPase Activity in Mitochondria.

The release of zoospores from sporangia and motility of the released zoospores are critical in the disease cycle of the Peronosporomycetes that cause devastating diseases in plants, fishes, animals and humans. Disruption of any of these asexual life stages eliminates the possibility of pathogenesis. In the course of screening novel bioactive secondary metabolites, we found that extracts of some strains of marine spp.

A New Lactone from Chaetomium globosum Strain M65 that Inhibits the Motility of Zoospores.

In a search for endophytes from medicinal plants of Bangladesh, we isolated the M65 fungal strain from the fruit of Azadirachta indica. Following chemical screening, chromatographic purification of the culture extract of strain M65 led to the isolation of the previously reported lasiodiplodin (2), the known derivative 1, and the new derivative 3a, along with two further known compounds (4 and 5). The new (3R,5R)-5-hydroxylasiodiplodin (3a), the enantiomer of the known (3S,5S)-5-hydroxylasiodiplodin (3b), inhibited the motility of zoospores of a devastating late blight phytopathogen Phytophthora capsici by 100% at a concentration of 10 μg/mL.

1-Acyl-3-0-[β-glucopyranosyl-(1"-+ 6')-β-glucopyranosyl]-glycerols and Cordycedipeptides B and C, New Metabolites from Bacillus pumilus.

Four 1-monoacyl-3-0-[β-glucopyranosyl-( ->6)-β-glucopyranosyl]-glycerols (1) and four 1,2-diacyl-3-0-[p-glucopyranosyl-(1->6)-p-glucopyranosyl]- glycerols (2a) with acyl residues consisting of 1:1 mixtures of 1-iso-pentadecanoyl- and 1 -anteiso-pentadecanoyl residues and the respective heptadecanoic acid isomers s as main components, have been characterized in the extracts of Bacillus pumilus strain DKS 1. Twenty-seven further metabolites, among them the diketopiperazines cordycedipeptide A (3), B (4), and C (5), were obtained. All compounds were elucidated by NMR and MS techniques and fully characterized and tested for antimicrobial activity against Legionella pneumophila.

Oligomycins and pamamycin homologs impair motility and induce lysis of zoospores of the grapevine downy mildew pathogen, Plasmopara viticola.

Four antibiotics (pamamycin, oligomycin A, oligomycin B and echinosporin) were isolated and characterized from the fermentation broth of the marine Streptomyces strains B8496 and B8739. Bioassays revealed that each of these compounds impaired motility and caused subsequent lysis of P. viticola zoospores in a dose- and time-dependent manner.

Marine Bacteria, XLVII - Psychrotolerant Bacteria from Extreme Antarctic Habitats as Producers of Rare Bis- and Trisindole Alkaloids.

From the gastrointestinal tract of a fish dredged near the South Orkney Islands in Antarctica, we isolated the psychrotolerant bacterial strain T262, which belongs to the species Vibrio splendidus. Investigation of this strain led to the isolation of a series of 15 bis- and trisindole derivatives. Among them, six new indole alkaloids, namely, turbomycin C [4'-n-butoxyphenyl-bis(1H-indol-3-yl)methane, 1a], turbomycin D [4'-n-propoxyphenyl-bis(1H-indol-3-yl)methane, 1b], turbomycin E [4'-ethoxyphenyl-bis(1H-indol-3-yl)methane, 1c], turbomycin F [4'-methoxy-3',5'-dinitrophenyl-bis(1H-indol-3-yl)methane, 2], trisindolal (3a), and 4-(1H-indol-3-yl-sulfanyl)phenol (4).

Antibacterial Azaphilones from an Endophytic Fungus, Colletotrichum sp. BS4.

Three new compounds, colletotrichones A-C (1-3), and one known compound, chermesinone B (4a), were isolated from an endophytic fungus, Colletotrichum sp. BS4, harbored in the leaves of Buxus sinica, a well-known boxwood plant used in traditional Chinese medicine (TCM). Their structures were determined by extensive spectroscopic analyses including 1D and 2D NMR, HRMS, ECD spectra, UV, and IR, as well as single-crystal X-ray diffraction, and shown to be azaphilones sharing a 3,6a-dimethyl-9-(2-methylbutanoyl)-9H-furo[2,3-h]isochromene-6,8-dione scaffold.

Xylactam B, A New Isobenzofuranone from an Endophytic Xylaria sp.

A new nitrogen containing compound named xylactam B (2), along with a further eight known compounds, ceramide 2a, cerebroside B, cyclo(prolyl,valyl), marmesin, 5-methoxycarbonylmellein, 5-methylmellein, polypropylene glycol and p-hydroxybenzoic acid, were isolated from an endophytic Xylaria sp. The structure elucidation of the new compound and the other isolates was carried out with the help of spectroscopic analyses and databases.

Macrocyclic Trichothecenes from Myrothecium roridum Strain M10 with Motility Inhibitory and Zoosporicidal Activities against Phytophthora nicotianae.

The cytotoxicity of the extract obtained from Myrothecium roridum M10 and a characteristic (1)H signal at δH ∼8 led to the assumption that verrucarin/roridin-type compounds were present. Upscaling on rice medium led to the isolation of four new metabolites: verrucarins Y (1) and Z (6) (macrocyclic trichothecenes), bilain D (12) (a diketopiperazine derivative), and hamavellone C (14) (an unusual cyclopropyl diketone). In addition, nine known trichothecenes [verrucarin A (3), 16-hydroxyverrucarin A (5), verrucarin B (7), 16-hydroxyverrucarin B (8), verrucarin J (2), verrucarin X (4), roridin A (9), roridin L-2 (10), and trichoverritone (11)] and a bicyclic lactone [myrotheciumone A (15)] were identified.