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The 5,4’-dihydroxy-3,7,8,3’-tetramethoxyflavone (ternatin, 1) was isolated from Egletes postrata (Plantae: Asteracea), and the structure was elucidated by interpretation of spectroscopic data and by comparison with reports of models structure in the literature. The flavone exhibits strong antioxidant properties as determined by inhibition of the oxidation of luminol by H 2 O 2 . The determined degree of inhibition of the oxidation of luminol was from 85 to 41% at concentrations of 53.5 and 1.07 μM of ternatin, respectively.

In a cultivation experiment 18 different Amaranthus genotypes were cultivated in parallel in Argentina, Mexico, Spain and two different locations in the Czech Republic. The ripe seeds were analysed for their content of 11 polyphenols and the variations among genotype, species and location were analysed by principal component analysis (PCA). The flavonoid, rutin, exhibited large variations with varying environmental conditions whereas the flavonoid, nicotiflorin, was affected less. Amaranthus hypochondriacus displayed the most stable content of polyphenols with a high end content of flavonoids. The variations between location/environmental condition were primarily described by the variations in the content of p-coumaric acid and protocatechuic acid in the seed samples.

Dogger Bank Itch is an allergic contact dermatitis representing a severe occupational hazard among trawlermen of the Dogger Bank Area in the North Sea. Allergic sensitivity is acquired following exposure to the marine bryozoan Alcyonidium gelatinosum. The allergen has been identified as (2-hydroxyethyl) dimethylsulfoxonium ion. The isolation, structure determination and synthesis of the allergen is discussed.

To deduce the structure of the large array of compounds arising from the transformation pathway of 6-methoxybenzoxazolin-2-one (MBOA), the combination of isotopic substitution and liquid chromatography analysis with mass spectrometry detection was used as a powerful tool. MBOA is formed in soil when the cereal allelochemical 2,4-dihydroxy-7-methoxy-1,4-benzoxazin-3-one (DIMBOA) is exuded from plant material to soil. Degradation experiments were performed in concentrations of 400 microg of benzoxazolinone/g of soil for MBOA and its isotopomer 6-trideuteriomethoxybenzoxazolin-2-one ([D3]-MBOA). Previously identified metabolites 2-amino-7-methoxyphenoxazin-3-one (AMPO) and 2-acetylamino-7-methoxyphenoxazin-3-one (AAMPO) were detected. Furthermore, several novel compounds were detected and provisionally characterized. The environmental impact of these compounds and their long-range effects are yet to be discovered. This is imperative due to the enhanced interest in exploiting the allelopathic properties of cereals as a means of reducing the use of synthetic pesticides.

Crude extracts of Haplopappus sonorensis (A. Gray) S.F. Blake (Asteraceae), showed activity against Mycobacterium tuberculosis H 37 Rv. By assay-guided fractionation, 5-hydroxy-3,7,4′-trimethoxyflavone ( 1 ), 5,7-dihydroxy-3,4′-dimethoxyflavone ( 2 ) and 5,4′-dihydroxy-3,7-dimethoxyflavone ( 3 ) were identified as the antimycobacterial principles. Compound 2 was the most active compound.

Pseudomonas sp. DSS73 was isolated from the rhizoplane of sugar beet seedlings. This strain exhibits antagonism towards the root-pathogenic microfungi Pythium ultimum and Rhizoctonia solani. Production of the cyclic lipopeptide amphisin in combination with expression of flagella enables the growing bacterial culture to move readily over the surface of laboratory media. Amphisin is a new member of a group of dual-functioning compounds such as tensin, viscosin and viscosinamid that display both biosurfactant and antifungal properties. The ability of DSS73 to efficiently contain root-pathogenic microfungi is shown to arise from amphisin-dependent surface translocation and growth by which the bacterium can lay siege to the fungi. The synergistic effects of surface motility and synthesis of a battery of antifungal compounds efficiently contain and terminate growth of the microfungi.

From a marine-derived strain of the fungus Emericella variecolor, varitriol (1), varioxirane (2), dihydroterrein (3), and varixanthone (4), besides the known mold metabolites ergosterol, terrein, shamixanthone, and tajixanthone hydrate, were identified. The chemical structures of 1-4 were established by means of spectroscopic techniques and some chemical transformations. In the NCI's 60-cell panel, varitriol (1) displayed increased potency toward selected renal, CNS, and breast cancer cell lines. Varixanthone (4) showed antimicrobial activity.

La 5,4’-dihidroxi-3,7,8,3’-tetrametoxiflavona (ternatina, 1) fue aislada de Egletes prostrata (Plantae: Asteracea) y la estructura fue elucidada por interpretación de datos espectroscópicos y por comparación con datos reportados para estructuras modelos. Esta flavona exhibió un fuerte efecto antioxidante determinado mediante inhibición de la oxidación del luminol inducida por H2O2. El grado de inhibición de la oxidación del luminol determinado fue de 85 a 41% a las concentraciones de 53,5 y 1,07 μM de ternatina, respectivamente, es considerado fuerte. The 5,4’-dihydroxy-3,7,8,3’-tetramethoxyflavone (ternatin, 1) was isolated from Egletes postrata (Plantae: Asteracea), and the structure was elucidated by interpretation of spectroscopic data and by comparison with reports of models structure in the literature. The flavone exhibits strong antioxidant properties as determined by inhibition of the oxidation of luminol by H2O2. The determined degree of inhibition of the oxidation of luminol was from 85 to 41% at concentrations of 53.5 and 1.07 μM of ternatin, respectively.

The main phenolic by-products in the O-benzylation of 1,2,4-trihydroxy-or 1,2,4-triacetoxybenzene to 1,2,4-tribenzyloxybenzene have been identified as due to incomplete O-benzylation and C-benzylation. In addition, dibenzyldimethylammonium chloride is formed from DMF and benzyl chloride. The main factors controlling these reactions paths are discussed. An efficient procedure for preparing 1,2,4-tribenzyloxybenzene using NaH in DMF is reported.

A new method for fast and easy monitoring of the presence, isolation, and separation of natural chloro compounds in plants is described. The method relies on the in vivo incorporation of radioactive 36Cl and new enhancement methods in autoradiographic technology. The method allows the time of exposure to be limited to 4 days and is thus suitable for routine purposes.

Two new carboxylic acids, tanzawaic acid E (1) and F (2) in addition to the unknown benzopyran 3,7-dimethyl-1,8-dihydroxy-6-methoxy-isochroman (3), and the known mycotoxin 3,7-dimethyl-8-hydroxy-6-methoxyisochroman (4) were produced by a marine-derived strain of Penicillium steckii isolated from an unidentified tunicate. The carboxylic acids and the benzopyran were identified on the basis of mass spectrometry, and one and two dimensional NMR spectroscopic techniques. The structures 1 and 2 resemble tanzawaic acid A–D, previously isolated from Penicillium citrinum. Screening of isolates of species related to P. citrinum and P. steckii showed that P. citrinum (25 isolates) consistently produced citrinin and tanzawaic acid A, P. steckii (18 isolates) produced isochroman toxins (except 2) and tanzawaic acid E, P. sizovae consistently produced tanzawaic acid A, P. corylophilum (10 isolates) produced citreoisocoumarinol and P. sumatrense (15 isolates) always produced curvularin.

Three 1,3-dithiolanes and four 1,3-dithianes have been synthesised from 1-(1,3-dithiolan-2-yl)-2-propanone and 1-(1,3-dithian-2-yl)-2-propanone, respectively. Asymmetric reductions of these ketones using baker's yeast gave the corresponding enantiopure (S)-alcohols. Baker's yeast also reduced the double bond in 3-(1,3-dithian-2-yl)-3-buten-2-one enantioselectively to give (S)-3-(1,3-dithian-2-yl)-2-butanone. 3-(1,3-Dithian-2-yl)-3-buten-2-one was also reduced chemo-selectively and the resulting 3-(1,3-dithian-2-yl)-3-buten-2-ol was resolved by transesterification in organic solvent using lipase B from Candida antarctica to yield the (S)-alcohol and the (R)-acetate with very high enantiomeric ratio, E. Racemic 1-(1,3-dithiolan-2-yl)-2-propanol and 1-(1,3-dithian-2-yl)-2-propanol were also resolved under similar conditions to give the (S)-alcohols and the corresponding (R)-acetates.

A total of 227 marine isolates of ubiqituous fungi were cultivated on different media and the secondary metabolite content of the extracts (ethyl acetate/chloroform/methanol 3 : 2 : 1) characterized by HPLC. The fungi were secured from animals, plants and sediments of Venezuelan waters (0–10 m) including mangroves and lagoonal areas. The extracts were tested for antibacterial activity. A total of 7 were active towards Vibrio parahaemolyticus and 55 towards Staphylococcus aureus, representing 18 different fungal species from 8 ascomycetous genera. For 61 strains of Penicillium citrinum antibacterial activity correlated well with content of secondary metabolites as measured by HPLC. Thirteen isolates of Penicillium steckii produced very similar profiles of secondary metabolites and 6 of these had activity against either V. parahaemolyticus or S. aureus or both.

The solid-state structure of Boc-Gly-Trp-Ala-OBut was determined by single-crystal X-ray diffraction analysis. The tripeptide gave crystals belonging to the orthorhombic systemP212121 and at 122.0(5) K:a=11.0663(12),b=14.107(2),c=17.275(2) A,V=2697.0(5) A3Z=4,R(F)=0.0259, andR w(F)=0.0695. The peptide adopts a type-Iβ-turn in the solid state with a single, rather weak, intramolecular hydrogen bond between the Boc-CO and Ala-NH groups (N⋯O 3.082(1) A

The optimal conditions were established for extraction of paralytic shellfish toxins from a Danish clone of Alexandrium tamarense using extraction with acetic acid and HCl in the concentration range 0.01–1.0 N. Physical destruction of the cells was investigated microscopically to select the most efficient extraction procedure.

A siderophore, pseudomonine, and sodium salicylate were isolated from the culture broth of iron-deficient cultures of Pseudomonas fluorescens AH2 isolated from the surface of spoiled Nile Perch from Lake Victoria

Batch cultures of the dinoflagellate Alexandrium ostenfeldii (Paulsen) Balech et Tangen were characterized by an exponential growth phase ending after 10 days. Three different paralytic shellfish poison (PSP) toxin patterns (A, B, and C) occurred at days 3, 6 and 10, respectively. The main toxins in pattern A were: 53% GTX6, 26% C4, 17% GTX5; B: 62% GTX4, 17% GTX6, 16% C3; C: 31% GTX4, 28% GTX6, 26% C4, 13% C3. Batch cultures (with identical pattern A) were challenged (elicted) on day 3 with various organic compounds and extracts of Alexandrium tamarense . After elicitation each toxin concentration changed on both day 6 and 10. A causal relation between properties of the elicitor and the resulting toxin pattern could not be established. It is proposed that toxins responding with small relative standard variations from the mean concentration (STX, neoSTX, GTX3, GTX4, GTX6 and C3) are characteristic for the batch culture. Toxins with high variability (GTX1, GTX2, GTX5, C2 and C4) change concentration as a result of stress provoked by the elicitors. The toxicity (estimated from standard values) of some elicited cultures had increased by a factor of 4 on day 10 indicating that stimulation of blooms of A. ostenfeldii may have substantial consequences regarding the problem of paralytic shellfish poisoning.

The structures of colorless, red, and yellow-orange fluorescein have been investigated by a combination of solution and solid state13C NMR. It is demonstrated that the three forms have lactonic, zwitterionic, and quinoid structures, respectively. Conflicting X-ray, NMR, and IR structural evidence is discussed for samples of red fluorescein which cannot readily be obtained in definite crystalline form. It is concluded that solid-state13C NMR spectroscopy is superior by revealing primarily the molecular structure but being fairly insensitive toward lattice variations.

Investigation of the ethanolic extracts from Phytolacca rivinoides and P. bogotensis has resulted in the isolation of five new triterpenoid glycosides of serjanic acid. Their structures have been established mainly by spectroscopic methods (FAB-MS, 1H, 13C NMR, COSY, NOESY, TOCSY, HETCOR and J-resolved 1H NMR) as 3-O-(O-beta-D-galactopyranosyl-(1-->3)-O-beta-D-glucopyranosyl)serjan ic acid 28-O-beta-D-glucopyranosyl ester, 3-O-(O-beta-D-glucopyranosyl-(1-->3)-O-[beta-D-galactopyranosyl-(1-->4)] -O- beta-D-glucopyranosyl)serjanic acid 28-O-beta-D-glucopyranosyl ester, 3-O-(O-alpha-L-rhamnopyranosyl-(1-->2)-O-beta-D-glucopyranosyl-(1-->2)- O-beta-glucopyranosyl)serjanic acid 28-O-beta-D-glucopyranosyl ester, 3-O-(O-beta-D-glucopyranosyl-(1-->3)-O-beta-D-galactopyranosyl-(1-->4)- O-beta-D-glucopyranosyl)serjanic acid 28-O-beta-D-glucopyranosyl ester and 3-O-(O-beta-D-galactopyranosyl-(1-->4)-O-[beta-D-glucopyranosyl-(1-->3)] - O-beta-D-glucopyranosyl)serjanic acid.

A convenient and fast method for establishing the relative antioxidant activity of chromatographically purified fractions of plant extracts has been developed. The assay electrochemically determines the myoglobin-catalyzed oxygen consumption following addition of the fractions to methyl linoleate. Since the oxygen consumption rate decreases with increasing antioxidant activity, the method can be used for systematic screening of naturally occurring antioxidants. Applying this method to extracts of Satureja hortensis led to isolation of rosmarinic acid.

Microalgae are known to produce toxins which affect the marine ecosystems. This include compounds active against competitors, grazers and in many cases also fish (1,2). Many strategies can be followed for discovery of novel bioactive secondary metabolites from marine sources. We have previously demonstrated that phenotypic based chemotaxonomy can be successfully used as the intial step in selection of talented strains for testing in various bioassays, using multivariate methods for clustering of whole profiles of metabolites. The second and very important step in the discovery process is dereplication, where we use explorative solid-phase extraction (E-SPE), and UHPLC-state-of-the-art high resolution mass spectrometry (

Isethionic acid (2-hydroxyethanesulfonic acid) was isolated as salts from a methanolic extract ofHypnea musciformis collected in the Indian Ocean and identified by comparison (nuclear magnetic resonance, infrared and mass spectrometry) with an authentic sample. The compound has not previously been reported from plants. Investigations of 13 other species of red algae showed that only some samples of species of the families Gigartinaceae, Hypnaceae and Solieriaceae (all of order Gigartinales) contained isethionates.

Lokisin was isolated from Pseudomonas sp. strain DSS41 as part of a study of prospective anti-fungal bio-control agents. Based on NMR and MS studies, lokisin was tentatively identified as pholipeptin. However, detailed analysis of the amino acid constituents by chiral gas chromatography revealed a different d-/l-leucine ratio of 3:2 and the allo-isomer of threonine. Lokisin represents a new structural variation in the cyclic lipoundecapeptide class.

Atlantinone A has been isolated from the psychrotolerant fungus Penicillium ribeum. The exact structure of the compound was confirmed by mass spectrometric and 1- and 2D NMR experiments. Atlantinone A was originally only produced upon chemical epigenetic manipulation of P. hirayamae, however in this study the compound was found to be produced at standard growth conditions by the following species; P. solitum, P. discolor, P. commune, P. caseifulvum, P. palitans, P. novae-zeelandiae and P. monticola. A biosynthetic pathway to atlantinone A starting from andrastin A is proposed.

The claim that N-mercapto-4-formylcarbostyril was isolated from Pseudomonas fluorescens strain G308 is questioned since N-thiols appear to be unstable compounds at ambient temperature.

Degradation of biochanin A, 400 μg (1.41 μmol) per gram of dry soil, was studied and the initial degradation products, dihydrobiochanin A, pratensein and genistein were identified and quantified. The maximum concentrations of these compounds were determined as 166 pmol/g dry soil after 2 days of incubation, 175 pmol/g dry soil after 1 day and 1,236 pmol/g dry soil after 1 day, respectively. Biochanin A and the initially formed products degrade too fast to be responsible for clover soil sickness (DT90

Four new 6-bromoindoles and the known 6-bromoindole-3-carbaldehyde {5} have been isolated from the marine sponge Pseudouberitesd hyalinus collected in the North Atlantic around the Faroe Islands. The structures of 6-bromoindolyl-3-acetonitrile {1}, 6-bromoindolyl3-acetamide {2}, methyl 6-bromoindolyl-3-acetate {3}, and 6-bromoindole-3-carboxylic acid {4}, were elucidated by analysis of ir, mass, 1 H-nmr, and 13 C-nmr spectral data, and structures 1-3 were confirmed by synthesis