A rapid-room temperature synthesis of α-cyanoacrylates, α-cyanoacrylonitriles and 4H-pyrans using water extract of pomegranate ash as catalytic media

In this article we report a sustainable and rapid-room temperature synthesis of α-cyanoacrylonitriles, α-cyanoacrylates, and 4H-pyrans via the condensation of active methylene compounds with aldehydes, and a three-component reaction of 1,3-dicarbonyl compounds/4-hydroxycoumarins, active methylene compounds and acetylene dicarboxylates in water extract of pomegranate ash (WEPA). The agro-waste-derived WEPA acts both as catalyst and aqueous reaction medium. The products of this process were separated by simple filtration and purified by recrystallization. This protocol did not require organic solvent-based work-up and column chromatography-assisted purifications. The use of renewable catalytic media, good reusability of catalyst, ease of handling, ambient and depleting resources-based catalyst free conditions, avoid of volatile organic solvents throughout the process, excellent product yields, and actual usage of waste are the highlights of this process.     

Assessment of the in vitro and in vivo genotoxicity of extracts and indole monoterpene alkaloid from the roots of Galianthe thalictroides (Rubiaceae)

Roots of Galianthe thalictroides K. Schum. (Rubiaceae) are used in folk medicine in the State of Mato Grosso do Sul, Brazil, for treating and preventing cancer. To gain information about the genotoxicity of extracts (aqueous and EtOH), the CHCl₃ phase resulting from partition of the EtOH extract and the indole monoterpene alkaloid 1 obtained from this plant. The genotoxicity of 1 and extracts was evaluated in vivo through the Drosophila melanogaster wing Somatic Mutation and Recombination Test – SMART, while in vitro cytotoxic (MTT) and Comet assays were performed only with alkaloid 1. The results obtained with the SMART test indicated that the aqueous extract had no genotoxic activity. The EtOH extract was not genotoxic to ST descendants but genotoxic to HB ones. The CHCl₃ phase was genotoxic and cytotoxic. Alkaloid 1 showed significant mutational events with SMART, in the cytotoxicity assay (MTT), it showed a high cytotoxicity for human hepatoma cells (HepG2), whereas for the Comet assay, not showing genotoxic activity. The ethanol extract was shown to be genotoxic to HB descendants in the SMART assay, while the results obtained in this test for the monoterpene indole alkaloid 1 isolated from this extract.     

Role of micellar nanoreactors in organic chemistry: Green and synthetic surfactant review

Over the last few decades surface active compounds in aqueous media have proven to be the most benign alternative for overcoming the difficulty of insolubility and hydrolytic breakdown of numerous non-polar compounds in aqueous medium. Surfactants have the unique ability to from micelles when they reach the critical micelle concentration, form emulsion and also help in solubilizing immiscible organic reagents in organic reactions and hence are a valuable asset in organic chemistry. Biosurfactants or green surfactants are amphiphilic compounds, often extracellularly secreted by variety of plants, animals and microorganisms as a means of secondary metabolites by utilizing varieties of waste raw materials and are a promising candidate to replace harmful organic solvents as well as synthetically designed surfactants owing of their remarkable traits like low toxicity, functionality under adverse conditions, based on renewable ingredients, and biodegradable nature, there is growing interest in this issue. Numerous organic reactions in water are now possible without the use of rather toxic and non-biodegradable organic solvents, thanks to the advent of new and greener biosurfactants into the field of organic chemistry.     

Airborne particulate matter modulates the production of reactive oxygen species in human polymorphonuclear granulocytes

Causal relationships between airborne particles (especially particulate matter < 10 μm in diameter) and increases in prevalences and symptoms of respiratory diseases have been postulated in many epidemiologic studies. Polymorphonuclear leukocytes (PMN) in the nasal or bronchial epithelium can be exposed to particulate matter (PM) and may upon exposure produce reactive oxygen species (ROS). Release of ROS can result in cellular and tissue damage and initiate or exacerbate inflammation. To elucidate the effect of PM on inflammatory reactions, we exposed human PMN to PM extracts. PM were collected with high volume samplers in two cities, Düsseldorf and Duisburg, in Germany and reflect sites with high traffic and industrial emissions respectively. The collected particles were extracted using water and then dichloromethane, resulting in an aqueous and an organic extract. The production of ROS was determined using luminol-enhanced chemiluminescence (LCL) of resting and zymosan-stimulated PMN. The present study shows that extracts of PM alone significantly stimulated the production and release of ROS in resting PMN. The effects of the PM extracts were inhibited by superoxide dismutase (SOD), catalase and sodium azide (NaN₃). Zymosan-induced LCL was, however, diminished by coincubation with PM extracts. The chemical composition is important when considering the effects of particles. Our study shows that only organic substances adsorbed to particles stimulate LCL. SOZ-induced LCL is inhibited by both types of extracts, but aqueous extracts have a stronger inhibitory effect. It is at present unclear which substances are responsible for these effects.     

Mechanism of hydrolysis of a novel indolocarbazole topoisomerase I inhibitor

The degradation kinetics and reaction product profile of the antitumor agent 1 in aqueous solution was studied. Hydrolysis of the pendant imide ring of 1 is the primary mode of thermal degradation in aqueous solution, and the pH rate profile of 1 has a V-shape indicating that hydrolysis of the imide ring can be catalyzed by either acid or base. Hydrolysis of 1 to the anhydride derivative 3 or the dicarboxylic acid derivative 4 is stepwise and the intermediates 2a and 2b formed by initial hydrolytic attack have been observed under alkaline conditions. An overall mechanism for the hydrolysis of 1 in aqueous solution has been proposed. Extrapolating Arrhenius behavior to the hydrolysis reaction of 1 in aqueous solution maintained at a pH value of 4 suggests an aqueous buffered formulation has sufficient thermal stability to be considered a robust room temperature drug product.     

Antimicrobial Activity and Phytochemical Constituents of Leaf Extracts of Cassia auriculata

Plants produce a wide variety of phytochemical constituents, which are secondary metabolites and are used either directly or indirectly in the pharmaceutical industry. ‘For centuries, man has effectively used various components of plants or their extracts for the treatment of many diseases, including bacterial infections. In the present study methanol, chloroform and aqueous extracts of Cassia auriculata leaf were subjected for antimicrobial activity by well-diffusion method against six bacterial strains namely Bacillus cereus, Staphylococcus aureus, Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa and Proteus mirabilis. The results revealed that the methanol and chloroform extracts exhibited strong inhibitory activity against all the tested organisms (zone of inhibition of 12-20 mm), except Pseudomonas aeruginosa (zone of inhibition 10 mm or nil). The aqueous extracts showed moderate activity by ‘Zone of inhibition ≤12 or nil). The extracts were screened for their phytochemical constituents by standard protocols’ and were shown to contain carbohydrates, proteins, alkaloids, flavonoids, steroids, saponins and tannins. The antibacterial activity of these extracts is possibly linked to the presence of flavonoids, steroid, saponins and/or tannins. Further studies are needed to determine the precise active principles from Cassia auriculata.     

Assessment of the influence of use on ecotoxicological characteristics of synthetic ester lubricants

Synthetic ester lubricants need optimisation about their technical and their ecotoxicological characteristics. To determine the ecotoxicological potential the required examinations can be based on the procedure for a risk assessment of chemicals. At present risk classification of lubricant oils is carried out with new oil fluids that are normally prepared before application in aqueous bioassays. In order to improve the ecotoxicological characteristics of some lubricant oils, the quality of the preparation method has been optimised. The resulting preparation protocol leads to aqueous extracts of the oil fluids that can be tested using biological assays. The extent of the changes of the chemical composition caused by the use as well as the ecotoxicological effects caused by additives have to be taken into consideration. For this reason various used lubricants are tested in addition to new oil fluids. In this work various lubricant samples were examined with standardised bacterial growth assays with Vibrio fischeri and Pseudomonas putida , luminescence inhibition assay with V. fischeri , survival assay with Daphnia magna and algal growth inhibition assay with Scenedesmus subspicatus . The chemical characterisation of the aqueous extracts included the determination of pH, conductivity, heavy metals, the content of dissolved organic carbon, inorganic anions and the content of phosphorus. The results emphasize the thesis that environmentally acceptable lubricants can undergo a change of their ecotoxicological potential during the use. Some of the substances that are normally added to base fluids in order to enhance the applicability of the oils may possess a high toxicological potential.     

Green approach for the valorization of microalgae Tetradesmus obliquus

The main goal of this study was to develop an efficient, green approach for the valorization of Tetradesmus obliquus biomass, with zero waste. This microalga was selected because it is widespread, resistant, easy for cultivation, and fast-growing. In the first step, supercritical carbon dioxide (ScCO₂) extraction followed by rapid gas decompression was used for the extraction of biomass. The following step was to apply ultrasound-assisted (UA), microwave-assisted (MA), and subcritical water (SW) extraction on the ScCO₂-treated biomass to determine the most efficient processing technology. SW demonstrated to be a superior technique over MW and UA with regard to extraction yield and antioxidant content. Moreover, the chemical and microbiological profiles of SW extracts were determined to evaluate their potential and safety. In addition, to create a procedure with zero waste, the solid waste after SW extraction (residue) was analyzed. The organic profile of extracts and residues contained compounds that belong to groups of aliphatic saturated hydrocarbons, aliphatic unsaturated hydrocarbons, alkylated hydrocarbons, ketones, phenols, and esters. Furthermore, these compounds can be applied in different industries including the pharmaceutical and cosmetic industries. Additionally, the content of metals in residues indicated that this material can be used as animal feed and in agriculture. Finally, a complete reduction of microorganisms present in the initial biomass was obtained for the extracts and residues, indicating their safety.     

Antiangiogenic Effect of Curcumin in Pure Versus in Extract Forms

Curcumin isolated from turmeric (Curcuma longa L., Zingaberaceae) root was found to be anti-angiogenic in a human tissue-based angiogenesis assay. As a liposoluble compound, curcumin can be extracted from turmeric root with organic solvents such as ethanol or acetone. Curcumin in its pure form has poor solubility in water, potentially limiting its medicinal use for humans when it is taken orally or injected. This study attempted to investigate the possibility of improving curcumin's low solubility using an extract as a carrier. This would maintain anti-angiogenic properties with improved water-solubility. Experiments were undertaken to determine the extraction efficiency of different solvents for curcumin. Anti-angiogenic activities of curcumin in its pure form and in extracts were compared as a general trend ethanol or acetone was more efficient in extracting curcumin than their aqueous counterparts. Using 50 and 70% aqueous ethanol as well as 70% aqueous acetone yielded significantly more turmeric extracts by weight than absolute acetone, which was the lowest. Conversely, turmeric extracts extracted with 95% ethanol and absolute acetone contained significantly higher curcumin concentrations than water extract, which was the lowest. Combining the higher extract yield and highest curcumin concentrations in the extract, 95% ethanol gave the highest yield of single entity curcumin. In the angiogenesis assay, pure curcumin at the concentration of 85 μ M (in 1% ethanol v/v) in the culture medium totally suppressed angiogenic responses. In contrast, a curcumin concentration of 18.5 μ M (in the form of 100 μ g/ml turmeric extract) achieved the same total inhibition of angiogenesis in culture. This nearly 5 fold gap reflected the unaccounted involvement of other antiangiogenic compounds including curcumin derivatives, and/or enhancement of curcumin by non-antiangiogenic compounds in the extract. This finding suggests that curcumin in the form of extracts be potentially more pharmacologically active than pure curcumin. Further investigations of this hypothesis and possible interactions are warranted.     

Sesquiterpenes from Petasites hybridus (Furanopetasin chemovar): Separation,isolation and quantitation of compounds from fresh plant extracts

A simple and easily reproducible MPLC and HPLC procedure allows separation and analysis of total extracts of Petasites hybridus and six furanoeremophilanes 1–6 have been isolated from fresh extracts of subterranean parts. Total sesquiterpene contents only slightly vary within the same population but moderately vary in four different habitats (Schwarzwald area, southern Germany). On the other hand, in total extracts relative amounts of main compounds 9-hydroxy-furanoeremophilane (2, 31–35%), furanopetasin (3, 18–22%) and 2-methylthioacryloyl-furanopetasol (6, 7–11%) are surprisingly constant for these four habitats, based on the same amount of extract. Contrary to the extracts of rhizomes, extracts of flowers contain 9-oxo-furanoeremophilane (2a) and 9-oxo-furanopetasin (3a) as main components instead of 2 and 3. Compounds 3 and 3a are the main constituents of extracts of leaves, but the composition of these extracts is much more complex.     

Toxicology Studies of a Chemical Mixture of 25 Groundwater Contaminants: I. Chemistry Development

As part of an effort to evaluate the toxicology of a chemicallydefined mixture of 25 frequently detected groundwater contaminants,we report here the formulation and analytical chemistry of thismixture. Many problems were anticipated, including limitationof solubility, chemical interactions, and extreme volatilityin the aqueous solution of 25 chemicals. The final technicallyachievable stock solution was prepared based on EPA survey concentrationsof these chemicals in groundwater around hazardous waste disposalsites, their toxicity information, and solubility of the individualcompounds in the matrix of the aqueous solution of these 25chemicals. Because the anticipated animal studies were to beconducted at various laboratories, for ease of handling andmaximum stability, the stock solution was stored or shippedas two substock solutions: an organic substock with 18 neatorganic chemicals in a glass vial sealed with minimum headspaceand an aqueous substock solution with 6 metals of various saltforms and phenol. The concentrations of the solutions were suchthat direct mixing of the organic and aqueous substocks producedthe desired high dose level for the animal experiments. Analysesof all 25 chemicals in the drinking water mixture required sixdifferent chromatographic and spectroscopic methods. Some lossof organic volatiles during mixing of the substocks and duringthe first 24 hr following preparation did occur. However, theconcentrations of acetone, phenol, and all the metals remainedconstant during preparation. Solutions held under simulatedanimal cage conditions for 96 hr showed losses of the organicvolatiles; the majority of which occurred within the first 24hr. This study shows that it is possible to conduct animal experimentson an aqueous mixture containing 25 groundwater contaminants.Furthermore, a reasonable estimate of intake of individual chemicalscan be achieved provided that dosing solutions are preparedfresh at frequent intervals (e.g., 48 to 72 hr) and that comprehensiveanalyses are earned out.     

Antimalarial Activity of Some Kenyan Medicinal Plants

This paper describes the in vitro antimalarial activity of eight species of plants popularly used traditionally to treat malaria in Kenya. Organic and aqueous extracts from different parts of the plants were tested. Generally, a stronger antimalarial activity was observed in the organic extracts. The most active extracts were of Vernonia brachycalyx O. Hoffm. Schreber. (Compositae) leaves which showed an IC 50 of 6.6 µg/ml for methylene chloride: ethyl acetate (1:1) extracts, while the aqueous and more polar methanolic extracts gave IC 50 values of 29.6 and 30 µg/ml, respectively. The findings of this study support the use of this plant as a traditional remedy for malaria. The rest of the plants tested gave IC 50 values between 30–100 µg/ml.     

Comparative assessment of kaempferitrin from medicinal extracts of Bauhinia forficata link

The leaves of the pantropical genus Bauhinia (Fabaceae) are popularly known as cow's-paw or cow's hoof due to their unique characteristic bilobed aspect. The species Bauhinia forficata (Brazilian Orchid-tree) is widely used in folk medicine as an antidiabetic. This article deals with the quantitative analysis of kaempferitrin from B. forficata medicinal extract (aqueous and hydro alcoholic) using the LC method, and the comparison of kaempferitrin content in leaves collected from two different regions in the south Brazil. The total flavonoid content assessed by LC was also compared with the classical spectrophotometric determination. Kaempferitrin was found in different amounts, in samples from two geographical areas (Telêmaco Borba/PR and Itajaí/SC), for aqueous (368.68 and 77.91 microg/mL) and hydro alcoholic extracts (1952.59 and 211.61 microg/mL), respectively. The method was subjected to recovery assay, to determine its accuracy. A marked difference in total flavonoid concentration was observed in relation to kaempferitrin content: 2759.95 and 2188.20 microg/mL for the fluidextract and 863.35 and 856.77 microg/mL for the aqueous extract (Telêmaco Borba/PR and Itajaí/SC). The spectrophotometric assay overestimated the total flavonoid content (3620 microg/mL) in relation to the LC assay.     

Surface and emulsifying properties of raw ethanolic extracts from legumes containing soyasaponins and proteins

The development of new amphiphilic compounds of natural origin is a challenging field of research in surfactant science. In this scenario, surfactants obtained from renewable organic sources is a valuable option to be exploited. The present work proposes raw ethanolic extracts containing soyasaponins, proteins and polysaccharides from legumes as surface active mixtures and stabilizers for emulsified systems. These extracts are produced by a green extraction process using an hydroalcoholic mixture (70:30 w/w) as solvent and six different legumes soybean, lentils, peas, beans, chickpeas, wild peas as starting materials. After freeze-drying, extracts were characterized in terms of total soyasoponin (from 1377 to 7354 mg/100 g), soyasaponin I (from 15 to 1459 mg/kg), soyasaponin VI (from 13 to 1076 mg/kg) and protein (16–28 g/100 g) contents. All extracts aqueous solutions show good surface active properties, being able to reduce the air-water surface tension to values comparable to those of the commonly employed surfactants (28–33 mN/m). Differences are observed in terms of emulsifying ability, since only lentils and soybeans extracts, thanks to their high soyasaponins and protein content, can act as stabilizers for emulsions containing up to 10% w/w of ethyl oleate (as oil phase) over six months of storage at 4 °C. These extracts are promising amphiphilic natural mixtures, potentially employable for food or pharmaceutical applications. Their relevance is also related to the possibility of using legumes derived from industrial wastes of food manufacturing, thereby giving valorization of by-products and residues in the context of a “circular economy” model.     

Pharmacological studies on seeds of Alangium salvifolium Linn

The seeds of Alangium salvifolium Linn. have been traditionally reported to exhibit a variety of biological activities, including antidiabetic, anticancer, diuretic, anti-inflammatory, antimicrobial, laxative, and antiepileptic activities. The objective of this study was to verify the traditional claims and to evaluate the seeds of Alangium salvifolium in various organic extracts to screen the antidiabetic, antiepileptic, analgesic and antiinflammatory activities. The chloroform, ethanol, and water extracts of Alangium salvifolium seeds were obtained and subjected for phytochemical screening and evaluated for their pharmacological activities. From the acute toxicity study it was observed that chloroform, ethanol, and aqueous extracts of Alangium salvifolium seeds are non-toxic at a fixed dose of 2000 mg/kg. Among all three extracts ethanol extracts exhibited significant (p < 0.01) antidiabetic, antiepileptic, analgesic and anti-inflammatory activities. The phytochemical analysis revealed the presence of alkaloids, glycosides, terpenoids, steroids and tannins. The results of present study verified the traditional claims made by ayurvedic practitioner. However, the chemical constituents responsible for the pharmacological activities remain to be investigated.     

Quantitative analysis of the anti-inflammatory activity of orengedokuto II: berberine is responsible for the inhibition of NO production

Orengedokuto is a Kampo formula that has been used for removing “heat” and “poison” to treat inflammation, hypertension, gastrointestinal disorders, and liver and cerebrovascular diseases. We report here our analysis of the anti-inflammatory effect of the component crude drugs of orengedokuto and their constituents using the inhibition of nitric oxide (NO) production in the murine macrophage-like cell line J774.1. An initial comparison of NO production inhibitory activities of the extracts of the component crude drugs and their combinations revealed that the activity could be attributed to Phellodendron Bark and Coptis Rhizome. Berberine (1), the major constituent of these crude drugs, showed potent activity (IC₅₀ 4.73?±?1.46 μM). Quantitative analysis of 1 in the extracts of all combinations of component crude drugs revealed that the amount of 1 in each extract of the combination of Scutellaria Root with either Phellodendron Bark and/or Coptis Rhizome was lower than that in the corresponding mixtures of the extracts of the individual crude drugs and that 1 was present in the precipitates formed during the decoction process. To the contrary, the differences in the amounts of 1 were smaller in the extracts containing Gardenia Fruit. These results indicated that the constituents of Scutellaria Root precipitated with 1 and that the constituents of Gardenia Fruit dissolved the precipitates. To identify the constituents affecting the solubility of 1, we fractionated the hot-water extracts of Scutellaria Root based on solubility tests of 1 to give baicalin (2), wogonin (3) and oroxyloside (4), which formed precipitates with 1.     

NMR and pattern recognition studies on liver extracts and intact livers from rats treated with alpha-naphthylisothiocyanate

The metabolite profiles from livers of toxin-treated rats were investigated using high resolution 1H NMR spectroscopy of aqueous (acetonitrile/water), lipidic (chloroform/methanol) extracts and magic angle spinning (MAS)-NMR spectroscopy of intact tissue. Rats were treated with the model cholestatic hepatotoxin, alpha-naphthylisothiocyanate (ANIT, 150 mg/kg) and NMR spectra of liver were analysed using principal components analysis (PCA) to extract novel toxicity biomarker information. 1H NMR spectra of control aqueous extracts showed signals from a range of organic acids and bases, amino acids, sugars, and glycogen. Chloroform/methanol extracts showed signals from a range of saturated and unsaturated triglycerides, phospholipids and cholesterol. The MAS 1H NMR spectra of livers showed a composite of signals found in both aqueous and lipophilic extracts. Following ANIT treatment, 1H NMR-PCA of aqueous extracts indicated a progressive reduction in glucose and glycogen, together with increases in bile acid, choline, and phosphocholine signals. 1H NMR-PCA of chloroform/methanol extracts showed elevated triglyceride levels. The 1H MAS-NMR-PCA analysis allowed direct detection of all of the ANIT-induced tissue perturbations revealed by 1H NMR of extracts, enabling metabolic characterisation of the lesion, which included steatosis, bile duct obstruction and altered glucose/glycogen metabolism. MAS-NMR spectroscopy requires minimal sample preparation and, unlike 1H NMR spectroscopy of tissue extracts, does not discriminate metabolites based on their solubility in a particular solvent and so this is a particularly useful exploratory tool in biochemical toxicology.     

In vitro breast cancer cell lethality of Brazilian plant extracts

In this study we screened the cytotoxicity of 1220 plant extracts obtained from 351 plants belonging to 74 families occurring in the Amazon and Atlantic rain forests against MCF-7 human breast adenocarcinoma cell lines. All extracts were tested at a dose of 100 microg/mL. Only 11 aqueous or organic extracts belonging to the Annonaceae, Apocynaceae, Araceae, Clusiaceae, Flacourtiaceae, Leguminosae, Olacaceae and Violaceae showed marked lethal activity. Vismia guianensis and Annona hypoglauca extracts showed the greatest lethal activity.     

Ethyl lactate and its aqueous solutions as sustainable media for organic synthesis

Ethyl lactate is an amphiphilic bio-based solvent with beneficial safety characteristics and ecotoxicity profile. The miscibility of ethyl lactate with water allows adjustments of the medium properties using aqueous solutions of various concentrations to achieve the desired reaction outcome. This review discuses current applications of ethyl lactate and its aqueous solutions as media for organic synthesis. The effectiveness of these media has been demonstrated in several coupling reactions, olefin metathesis, carbonyl group reactions, heterocyclizations, various multicomponent reactions and other chemical transformations. These reactions often benefit from the application of non-conventional energy sources (microwave, ultrasound, and visible light irradiation). The reaction yields are typically comparable or higher than that obtained in conventional solvents.     

Phytotoxic effects of sewage sludge extracts on the germination of three plant species

In order to evaluate the ability of three types of extracts to explain the ecotoxicological risk of treated municipal sewage sludges, the OECD 208A germination test was applied using three plants (Lolium perenne L., Brassica rapa L., and Trifolium pratense L.). Three equivalent batches of sludge, remained as dewatered sludge, composted with plant remains and thermally dried, from an anaerobic waste water treatment plant were separated. Samples from these three batches were extracted in water, methanol, and dichloromethane. Plant bioassays were performed and the Germination Index (GI) for the three plants was evaluated once after a period of 10 days. Germination in extracts was always lower than the respective controls. The germination in composted sludge (GI 40.9–86.2) was higher than the dewatered (GI 2.9–45.8), or thermally dried sludges (GI 24.6–64.4). A comparison of the germination between types of extracts showed differences for dewatered sludge with the three plants, where the water and methanol extracts had significantly lower germination than the dichloromethane extract. A higher half maximal effective concentration (EC50) in composted extracts was established, mainly in the water extract (EC₅₀ 431–490 g kg⁻¹). On the contrary, the germination was strongly inhibited in the water extract of the dewatered sludge (EC₅₀ 14 g kg⁻¹). The germination was positively correlated with the degree of organic matter stability of the parent sludge, and an inverse correlation was detected for total nitrogen, hydrolysable nitrogen and ammonium content. It is concluded that the phytotoxic effect of the water extract is more closely related to hydrophilic substances rather than lipophilic ones, and care must be taken with dewatered sludge application, especially with their aqueous eluates. Results obtained in this work show the suitability of the use of sludge extracts in ecotoxic assays and emphasize the relevance of sewage sludge stabilization by post-treatment processes.