In vitro microbiological evaluation of novel 2-oxo-2H-chromene-3-carbaldehyde containing 1,3,4-thiadiazole moiety

4-(5-(Methylthio)-1,3,4-thiadiazol-2-ylamino)-2-oxo-2H-chromene-3-carbaldehyde (3) and 4-(5-(ethylthio)-1,3,4-thiadiazol-2-ylamino)-2-oxo-2H-chromene-3-carbaldehyde (4) were prepared. The structures of the newly synthesized compounds were characterized by infrared (IR), nuclear magnetic resonance (NMR) spectral data and elemental analysis. The synthesized compounds were screened in vitro for their antibacterial activities. The synthesized compounds demonstrated moderate antimicrobial activity.     

Microbiological evaluation of 4-(6-chloro-7H-purin-8-ylamino)-3-nitro-chromen-2-one with a comparison to antibacterial activity of standard drugs

Nucleophilic substitution of 4-chloro-3-nitro-2-oxo-2H-chromen-2-one 3 by 6-chloro-7H-purin-2-ylamine (a), yielded the corresponding 4-(6-chloro-7H-purin-8-ylamino)-3-nitro-chromen-2-one 4. The chemical structure of synthesized compound was characterized using IR and NMR spectra, and elemental analyses. The purified synthesized compound 4 was tested at concentrations 1, 3, 5 mg/ml for its antibacterial activity against three bacterial cultures: Staphylococcus aureus, Escherichia coli, and Bacillus cereus. The antibacterial activity of synthesized compound was compared to antibacterial activity of standard antibiotics cephalexine and streptomycin.     

Genotoxicity,antifungal and antibacterial activity of newly synthesized N-(3-phthalidyl)amines and o-benzoyl benzamide derivatives

A number of newly synthesized phthalidylamines and o-benzoylbenzamide derivatives were evaluated for some biological activities. Synthesis was established by condensation of 3-acetoxyphthalide 1 with morpholine, piperidine, N,N-diisobutyl-N,N-dibenzylamines and piperazine, which afforded N-(3-phthalidyl)amines 3a–d, and 4 respectively, while with N,N-diisopropylamine, o-formyl-N,N-diisopropyl benzamide 5a is formed exclusively. On the other hand, the reaction of 3-acetoxy-3-phenylphthalide 2 with secondary amines afforded o-benzoylbenzamide derivatives 5b–c, 6 in a high yield. The structure of the reaction products was established from their spectral data. These products were screened for antifungal, antibacterial and genotoxic effect. It was found that all tested compounds have antifungal activity. Compounds 1, 2, 3d and 5b were found to be active against Escherichia coli, Bacillus subtilis and Staphylococcus aureus. Genotoxic effects using Ames test showed that Compounds 1 and 2 have a weak base-pair substitution mutagenicity while a clear base-pair substitution mutagenic activity was shown by 3a using TA100-strain of Salmonella typhimurium. Compound 4 showed a frameshift mutgenicity while a weak oxidative mutagenic action was revealed by 6. No change on the mutagenicity of the tested chemicals was observed after using the S9 metabolic activation system.     

Is Scotland sustainable? A the series of indicators of sustainable development

Seven measures of sustainable development for Scotland are examined for the period 1980-1993. These measures are green net national product, genuine savings, ecological footprint, environmental space, human appropriation of net primary production, the index of sustainable economic welfare and the genuine progress indicator. Very different messages concerning sustainable development in Scotland emerge from these measures.     

Sequestration of prenylated benzoic acid and chromenes by Naupactus bipes (Coleoptera: Curculionidae) feeding on Piper gaudichaudianum (Piperaceae)

The curculionid beetle Naupactus bipes (Germar, 1824) (Coleoptera: Curculionidae: Brachycerinae) has shown feeding preference for leaves of Piper gaudichaudianum, demonstrating an unexpected specificity for an insect considered to be a generalist. The leaves of P. gaudichaudianum contain the prenylated chromenes gaudichaudianic acid (4, major compound) and its methyl ester (5) in addition to a chromene (3) lacking one prenyl residue. In addition to 4, roots contain the chromone methyl ester (1) and methyl taboganate (2, major compound). Feeding on roots, larvae of N. bipes sequester exclusively the root-specific compounds 1 and 2. Adult beetles sequester the leaf-specific chromenes 3 and 4, but were found to also contain compounds 1 and 2 that are absent in leaves. Therefore, it is suggested that 1 and 2 are sequestered by larvae and can be found in the body of adult insects after long-term storage. In addition, 3 and 4, the major compounds in leaves were found to be associated with the eggs.     

Synthesis and evaluation of antioxidant activities of some indole-2,3-dione derivatives and analogs

In the present study, a series of novel Schiff bases of isatin were synthesized by condensation of imesatin with different aromatic aldehydes. The imesatins were synthesized by reaction of isatin with p-phenylenediamine. The chemical structures of the synthesized compounds were confirmed by means of IR, 1H-NMR, 13C-NMR, mass spectroscopy, and elemental analysis. These compounds were screened for antioxidant activity by DPPH, nitric oxide and hydrogen peroxide radical scavenging activity. In all the methods, the compound 3-(4-(3,4,5-trimethoxy benzylideneamino)phenylimino) indoline-2-one (5d) showed highest antioxidant activity because of the presence of electron donating groups and the compound 3-(4-(4-nitrobenzylideneamino)phenylimino) indoline-2-one (5f) showed the least activity because of the presence of an electron withdrawing group.     

Matching species traits to environmental variables: a new three-table ordination method

This paper addresses the question of studying the joint structure of three data tablesR,L andQ. In our motivating ecological example, the central tableL is a sites-by-species table that contains the number of organisms of a set of species that occurs at a set of sites. At the margins ofL are the sites-by-environment data tableR and the species-by-trait data table Q. For relating the biological traits of organisms to the characteristics of the environment in which they live, we propose a statistical technique calledRLQ analysis (R-mode linked toQ-mode), which consists in the general singular value decomposition of the triplet (R ^t D _I LD _J Q,D _q ,D _p ) whereD _I ,D _J ,D _q ,D _p are diagonal weight matrices, which are chosen in relation to the type of data that is being analyzed (quantitative, qualitative, etc.). In the special case where the central table is analysed by correspondence analysis,RLQ maximizes the covariance between linear combinations of columns ofR andQ. An example in bird ecology illustrates the potential of this method for community ecologists.     

Sex pheromone components of male <Emphasis Type="Italic">Tirathaba mundella</Emphasis> (Lepidoptera: Pyralidae)

Summary. During peak calling activity by male oil palm bunch moths, Tirathaba mundella Walker (Lepidoptera: Pyralidae), their hairpencils, wings or entire body were extracted in hexane. Gas chromatographic-electroantennographic detection (GC-EAD) analyses of hair pencil extracts revealed four compounds that consistently elicited responses from female antennae. The NMR spectrum of isolated compound 1, and mass spectra and retention indices of compounds 1–4 suggested that they were (3S,6S)-2,2,6-trimethyl-6-vinyl-tetrahydro-pyran-3-ol (1), 4-hydroxy-3-methoxy-benzaldehyde (2, vanillin), 6,10,14-trimethyl-2-pentadecanone (3), and 6,10,14-trimethyl-2-pentadecanol (4). Comparative GC and GC-MS analyses of hair pencils extract and synthetic standards confirmed these structural assignments. Moreover, comparative chromatography of synthetic and hairpencil-isolated 1 on a Cyclodex-B column (which separated the four stereoisomers with baseline resolution) revealed that male T. mundella produce the SS-stereoisomer (SS-1). In field cage bioassay experiments in Palembang, Indonesia, synthetic SS-1 and vanillin in combination, but not singly, attracted female T. mundella. SS-1 plus vanillin were as effective as male T. mundella in attracting females. Compounds 3 and 4 did not enhance the blend's attractiveness. Received October 11 2002; accepted March 14, 2003. R1D=" Correspondence to: Gerhard Gries, email: gries@sfu.ca     

Differential activity of non-fluorinated and fluorinated analogues of the European corn borer pheromone

Summary.  The differing antagonist activity of (Z)-13-hexadecen-2-one (Z11 – 14 :MK, 1) and its 1,1,1-trifluoro derivative (Z11 –14 :TFMK, 2), two closely related analogues of the European corn borer pheromone Ostrinia nubilalis (Z strain), and their rationale is reported. Both chemicals exhibited some electrophysiological activity, and topical application of 10 pg of pheromone analogue on male antennae was sufficient to induce significantly lower depolarization responses to the pheromone versus untreated insects. In a wind tunnel, the number of European corn borer males attracted to sources containing mixtures of 1 + pheromone in ratios ≥ 1 :1 was significantly lower than the number attracted to a source containing pheromone alone. Source contact behaviour was dramatically impaired when the 1 + pheromone blend reached a ratio of 10 :1, in which only 2% of males displayed source contact in the presence of antagonist. When compound 1 was present at the source, males usually flew upwind with occasional downwind reversals; when compound 2 was present at the lure, males performed wider crosswind reversals, with little progress toward the source. In the field, traps baited with mixtures of both compounds with the pheromone in ratios of 5 :1 and 10 :1 elicited a significantly decreased number of male catches. In esterase inhibition assays, compound 2 was a potent inhibitor (IC₅₀ = 70 nM), whereas the non-fluorinated compound 1 was not. The different activity of both compounds is presumed to be due to different mechanisms of action; considerations for using methyl ketone analogues as new behavioural antagonists of the pheromone are outlined.     

Synthesis and biological activities of new azacrown ether Schiff bases and spectrophotometric studies of their complexation with [60]fullerene

A series of novel azacrown ether Schiff bases 1–3 have been synthesized in good yield and in a simple way. Their host–guest interaction with [60]fullerene has been studied in toluene by absorption spectroscopic method. All the complexes are found to be stable with 1:1 stoichiometry. Because of their potential applications in industry, agriculture and medicine, they were investigated for their mutagenic and antimutagenic activities using the spot test and the plate incorporation assay of Ames. Compounds 1, 2 and 3 were found to be nonmutagenic in the Ames test using strains TA 1535, TA100 and TA97a of Salmonella typhimurium. However, using strain TA102 revealed that, although both compounds 1 and 2 were nonmutagenic, compound 2 gave a positive response indicating that it acts as an oxidative mutagen. The structure-activity relationship may throw some light on the biological activity of such series of compounds.     

Enhancement of association of organic molecules on silica gel by surface water: surface photoreaction of stilbene

Here, we show that association of stilbene molecules is facilitated by water on silica gel because of hydrophobic interaction and photodimerization becomes the main photochemical process. Irradiation of trans-stilbene (t-1) on silica gel gives cis-stilbene (c-1), phenanthrene (2), benzaldehyde (3), and dimers r-ctt-4 and r-tct-4. The yields of the dimers increase and those of 2 and 3 decrease with an increase in the amount of t-1 loaded on silica gel. Atmospheric oxygen is responsible for the formation of 2 and 3. The yields of the dimers also increase with an increase in the water on a silica-gel surface and change drastically at the point where the percentage of water to silica gel is around 25 wt%. All active sites on a silica-gel surface would be covered completely with 25 wt% of water.     

Simulating correlated count data

In this study we compare two techniques for simulating count-valued random n-vectors Y with specified mean and correlation structure. The first technique is to use a lognormal-Poisson hierarchy (L-P method). A vector of correlated normals Z is generated and transformed to a vector of lognormals X. Then, Y is generated as conditionally independent Poissons with means X _i . The L-P method is simple, fast, and familiar to many researchers. However, the method requires each Y _i to be overdispersed (i.e., σ² > μ), and only low correlations are possible with this method when the variables have small means. We develop a second technique to generate the elements of Y as overlapping sums (OS) of independent X _j ’s (OS method). For example, suppose X, X ₁, and X ₂ are independent. If Y ₁ = X + X ₁ and Y ₂ = X + X ₂, then Y ₁ and Y ₂ are correlated because they share the common component X. A generalized version of the OS method for simulating n-vectors of two-parameter count-valued distributions is presented. The OS method is shown to address some of the shortcomings of the L-P method. In particular, underdispersed random variables can be simulated, and high correlations are feasible even when the means are small. However, negative correlations cannot be simulated with the OS method, and when n > 3, the OS method is more complicated to implement than the L-P method.     

Predictions of Cu toxicity in three aquatic species using bioavailability tools in four Swedish soft freshwaters

Background

The EU member countries are currently implementing the Water Framework Directive to promote better water quality and overview of their waters. The directive recommends the usage of bioavailability tools, such as biotic ligand models (BLM), for setting environmental quality standards (EQS) for metals. These models are mainly calibrated towards a water chemistry found in the south central parts of Europe. However, freshwater chemistry in Scandinavia often has higher levels of DOC (dissolved organic carbon), Fe and Al combined with low pH compared to the central parts of Europe. In this study, copper (Cu) toxicities derived by two different BLM software were compared to bioassay-derived toxicity for Pseudokirchneriella subcapitata, Daphnia magna and D. pulex in four Swedish soft water lakes.

Results

A significant under- and over prediction between measured and BLM calculated toxicity was found; for P. subcapitata in three of the four lakes and for the daphnids in two of the four lakes. The bioassay toxicity showed the strongest relationship with Fe concentrations and DOC. Furthermore, DOC was the best predictor of BLM results, manifested as positive relationships with calculated LC₅₀ and NOEC for P. subcapitata and D. magna, respectively.

Conclusion

Results from this study indicate that the two investigated BLM softwares have difficulties calculating Cu toxicity, foremost concerning the algae. The analyses made suggest that there are different chemical properties affecting the calculated toxicity as compared to the measured toxicity. We recommend that tests including Al, Fe and DOC properties as BLM input parameters should be conducted. This to observe if a better consensus between calculated and measured toxicity can be established.

     

Persistence of the sulfonylurea herbicide iodosulfuron-methyl in the soil of winter wheat crops

On four winter wheat fields grown on soils of different textures in Belgium, 10?g a.i.?ha^?1 of the sulfonylurea herbicide iodosulfuron-methyl-sodium was applied post-emergence in the spring. A procedure was developed for the analysis in field soils of iodosulfuron-methyl 1 and of its metabolites iodosulfonamide 2 and iodosaccharin 3 with a sensitivity limit of 0.3?µg of equivalents of iodosulfuron-methyl 1 kg^?1 dry soil. GC and GC-MS was used after purification of the soil extracts by repeated TLC, and methylation. The results of the chemical analyses were confirmed by means of bioassays using sugar beet as test plants. On a winter wheat crop grown on sandy loam soil of pH 6.2 at Melle, iodosulfuron-methyl-sodium 1 was applied at the beginning of April. The iodosulfuron-methyl 1 soil half-life in the 0–10?cm surface soil layer was 60 days. At the end of June, the sum of the concentrations of the metabolites 2 and 3 in the 0–10?cm surface soil layer attained a maximum corresponding to 27% of the applied dose. Green manures were sown after the harvest of the wheat at the end of August. No phytotoxicity at all was observed during the growth of the green manures, in spite of the very low residues of iodosulfuron-methyl 1 remaining in soil in September and October. At the mid of November, iodosulfuron-methyl 1 and its metabolites 2 and 3 were no more detected in soil. On three other winter wheat crops grown on clay soils of pH of about 8 at Leke, Gistel and Zevekote, iodosulfuron-methyl-sodium 1 was applied at the beginning of May. The soil half-life of iodosulfuron-methyl 1 in the 0–10?cm surface soil layer was between 30 and 44 days. Since the application and until the mid of November, in all the trials made on sandy loam or clay soils, iodosulfuron-methyl 1 (and its metabolites 2 and 3 in the trial made on sandy loam soil) were never detected in the 10–15 and 15–20?cm surface soil layers, indicating their low mobilities in the field soils.     

Influence of 1,2,4,5-tetrazine derivatives on growth of bacterial consortium isolated from soil

This article presents the results of laboratory studies of the influence of tetrazine derivatives on the growth kinetic parameters of soil bacteria. 3,6-Dihydrazinotetrazine (DHTz), 3,6- bis(3,5-dimethylpyrazol-1-yl)-dihydro-1,2,4,5-tetrazine (DMPDHT) and N,N′-bis(1,2,4,5-tetrazine-6-(3,5-dimethylpirazylo))hydrazine (BDMPT) were applied. 3,6-Dihydrazinetetrazine had the largest influence on the growth of bacteria, reflected in a significant lengthening of the lag-phase and a decrease in the specific growth rate. Dehydrogenase activity was also determined in bacterial cultures exposed to tetrazine derivatives. Dehydrogenases remained active even at DHTz concentrations of 80 mg · L^?1, which completely inhibited bacterial growth. The compounds studied variously influence the kinetics of growth in the bacterial consortium; at the same time, they undergo biodegradation in soil by autochthonous microflora.     

The effect of food supply on feeding strategy in sessile female gastropods<Emphasis Type="Italic"> Crepidula fecunda</Emphasis>

Sessile females of the gastropod Crepidula fecunda are exclusively suspension-feeders. Our previous work showed that particles removed from suspension are entrained on the gill and continuously accumulate as a mucous string on the distal margin of the lamella, although some are transferred by a ciliary tract to the food pouch, where they form a mucous ball. The mucous string is transferred from the gill margin to the neck canal, where it forms a mucous cord which is transported to the mouth. The mucous ball and the mucous cord are ingested with the aid of the radula. In this study we examined the response of the system to a wide range of cell concentrations of the flagellate Isochrysis galbana. As the particle concentration increased from 5,000 to 200,000 cells ml^-1, the volume of the mucous ball almost doubled, as did the number of radular extrusions required to ingest it. The total volume of mucous balls produced and ingested increased very slightly as particle concentration rose from 5,000 to 100,000 cells ml^-1, but the volume of mucous cord material ingested increased four to five times over the same range. At higher food concentrations the mucous cord increased in thickness, but not in length, which is constrained by the length of the gill margin. At all particle concentrations the mucous cord accounted for 80–95% of the total material (mucous cords plus mucous balls). Ingestion rate reached a maximum at 140,000 cells ml^-1 for mucous balls and mucous cords. At higher concentrations the production of pseudofaeces increased from all sources ("type-I" pseudofaeces from rejected mucous balls; "type-II" pseudofaeces from rejected fragments of mucous cords; and "type-III" pseudofaeces, which come from particles trapped in a coarse mucous net at the mouth of the inhalant mantle cavity and are transferred via the lateral ciliary tract to the mantle margin, by-passing the food pouch). Thus C. fecunda has adopted a feeding strategy in which particle entrainment by the gills is continuous, even at very high ambient particle concentrations (200,000 cells ml^-1 for I. galbana), and excess material which cannot be ingested is rejected by one or more of three routes for the elimination of pseudofaeces.Communicated by P.W. Sammarco, Chauvin     

Potential application of 2-(6-ethylamino-3-ethylimino-2,7-dimethyl-3H-xanthen-9-yl) benzoic acid phenyl thiourea for mercury determination

Heavy metal contamination of the environment is a public health problem and research to develop new tools for monitoring the environmental impact of these elements is necessary. This study describes the preparation of a rhodamine-based probe 1 and its potential applications for detecting mercuric ion [Hg(II)] in samples from a nutrition media containing Salvinia auriculata. It was observed that an excess of probe 1 led to quenching in the fluorescence/absorption response, which was evidenced by a decrease in the signal when the stoichiometry differed from 1:1. Consequently, this probe is not suitable for quantitative analysis of Hg(II). Also, probe 1 reacts with methylmercury (MeHg) with different stoichiometry than that observed for Hg(II). These results indicate the potential application of probe 1 for qualitative detection of Hg(II) and MeHg in environmental samples.     

Synthesis and in vitro biological evaluation of 3, 4-annelated coumarin-pyrimido-pyrimidine systems

3,4-Annelated coumarin-pyrimido-pyrimidine systems (7-imino-8-mercapto-7H-5-oxa-7a,9,12-triaza-benzo[a]anthracen-6-one 2 and 8-hydroxy-7-imino-10-methyl-7H-5-oxa-7a,9,12-triaza-benzo[a]anthracen-6-one 3) were synthesized by the action of 4-amino-2-mercapto-pyrimidine, 2-amino-4-hydroxy-6-methylpyrimidine, respectively, on 4-chlorocoumarin-3-carbonitrile 1. The synthesized compounds were examined for in vitro antibacterial activity against 4 bacterial cultures: Staphylococcus aureus, Streptococcus pneumonia, Escherichia coli, and Aeromonas Salmonicida. The antibacterial activity of synthesized compounds 2 and 3 was compared to antibacterial activity of novobiocin as a standard drug.     

Vegetation zonation and management in the Damietta estuary of the River Nile

The zonation of the vegetation along the saline and freshwater marshes of the Damietta estuary of the Nile River was studied from near the river mouth to 20 km upstream. Downstream, the estuarine water is almost stagnant and highly saline with high concentrations of nutrients. This makes the habitat unsuitable for euhydrophytes. Upstream, the vegetation consists mostly of freshwater macrophytes. 75 sampling plots were established in representative stands of the upshore and upstream vegetation zones. Classification and ordination of the data revealed seven vegetation types, indicated A—G. The dominant species of the saline marshes werePhragmites australis, Tamarix nilotica andArthrocnemum macrostachyum (A),Zygophyllum aegyptium andPolygonum equisetiforme (B),Cynodon dactylon andSuaeda vera (C). In the freshwater marshes the dominants were:Ludwigia stolonifera, Persicaria lapathifolia (D),Typha domingensis (E),Eichhornia crassipes (F) andCeratophyllum demersum (G). The first axis of the ordination axis obtained with Detrended Correspondence Analysis can be associated with the upstream gradient. It separates the salt marsh vegetation groups from those of the freshwater marshes. Plant species richness increased upshore along both saline and freshwater marshes. The concentration of dominance increased upstream. Some aspects of proper management of estuarine vegetation are mentioned.     

Fungicidal activity and molecular modeling of fusarubin analogues from Fusarium oxysporum

Abstract

Fusarubin analogues of Fusarium oxysporum f. sp. ciceris were investigated for antifungal activity in vitro against five soil borne phytopathogenic fungi. 3-O-Methyl-8-O-methyl-fusarubin was inhibitory towards S. sclerotiorum (EC₅₀ 0.33?mmol L^?1) and Sclerotium rolfsii (EC₅₀ 0.38?mmol L^?1). A structure–antifungal activity relationship of fusarubin analogues was established from their activity performance. Possible mechanism of action of these compounds was studied using molecular docking and simulations against three target enzymes which revealed receptor ligand binding affinity. Docking of 3-O-methyl-8-O-methyl-fusarubin into the succinate dehydrogenase site revealed formation of salt bridge, hydrogen bond, π–anion, π–alkyl, and Van der Waals interactions.