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Pistacia lentiscus L. is one of the most popular medicinal plants attributed to its beneficial properties on human health. However, few toxicogenetic studies have been carried out. Therefore, the aim of this study was to examine the potential genotoxic/antigenotoxic and mutagenic/antimutagenic properties of oil, ethyl acetate and ethanolic extracts of P. lentiscus L. fruits using in vitro the Ames and Umu assays, as well as in vivo micronucleus (MN) test. Extracts did not exert any significant mutagenic/genotoxic effects but provided protection against standard mutagenic and genotoxic agents including 2 nitrofluorene (2-NF) at 2.5 and 5µg/ml; sodium azide at 5 and 10µg/ml; 3-methylcholanthrene (3-MC) at 25 and 50μg/ml; cyclophosphamide (CP) at 50 and 100μg/ml; 4-nitroquinoline 1-oxide (4-NQO) at 0.05µg/ml and 2-amino-anthracene (AA) at 0.2µg/ml. Further, cytotoxicity and selectivity were examined on human hepatocarcinoma (HepG2), and MCF-7 breast cancer cell lines as well as a human normal-like fibroblast cell line (TelCOFS02MA) using MTT assay. Among all extracts, PF1 (ethanolic) showed the most significant selectivity index (SI) (HepG2:11.98; MCF7:4.83), which led to further investigations using an animal model. Oral administration of PF1 (125–1000 mg/kg b.w.) significantly decreased the number of micronucleated cells in CP -initiated (50 mg/kg b.w.) mice, while the number of micronucleated reticulocytes (MNRET), micronucleated polychromatic erythrocytes (MNPCE) or mitotic index (MI) were not markedly affected. Further, PF1 significantly enhanced catalase (CAT) and superoxide dismutase (SOD) activities in the livers and kidneys of these animals. The obtained results indicated the beneficial properties of P. lentiscus L. fruits for use in therapy against harmful effects of genotoxic and mutagenic agents. However, while promising it should be noted that the obtained results are preliminary and need to be confirmed prior to therapeutic use.

Investigation of the ethyl acetate extract of Juncus acutus rhizomes revealed seven benzocoumarins, probably derived from oxidation of phenanthrenes already isolated from the plant. The structures were determined by means of spectroscopic methods. The anti- algal activity of the isolated compounds tested on the green alga Pseudokirchneriella subcapitata are reported here. q 2003 Elsevier Science Ltd. All rights reserved.

The development of new formulations can be driven by the knowledge of host–guest complexes using cyclodextrins which have the ability to include guest molecules within their hydrophobic cavities, improving the physicochemical properties of the guest. To rationally explore new pesticide formulations, the effects of cyclodextrins on the properties of such guest molecules need to be explored. Imidacloprid is a neonicotinoid systemic insecticide used worldwide. In this study, the inclusion complexes of Imidacloprid (IMI) with β-cyclodextrin (β-CD) were prepared in the solid state by co-precipitation and the physical mixing method, with a stoichiometry of 1:1 and 1:2 molar ratios. The obtained products, Imidacloprid:β-cyclodextrin inclusion complex (IMI:β-CD), were characterized in the solid state by Fourier transform-infrared (FT-IR) spectroscopy and X-ray powder diffractometry (XRD). In solution, the 1:1 stoichiometry for the inclusion complexes was established by the Job plot method, and the binding constant of IMI:β-CD was determined by UV–vis titration. The toxicity was determined in producers and primary consumers of the freshwater trophic chain, the green alga Raphidocelis subcapitata and the rotifer Brachionus calyciflorus, respectively. The results indicated that Imidacloprid forms inclusion complexes with CDs showing improved physicochemical properties compared to free Imidacloprid. The formation of the inclusion complex reduced the chronic toxicity in rotifers when IMI concentrations were close to those of environmental concern (tenths/hundredths of micromoles/L). Therefore, CD inclusion complexes could provide important advantages to be considered for the future industrial production of new formulations.

The curriculum for teacher training, which cannot be limited to soliciting the development of theoretical knowledge, must activate both a cyclical processes of action and a research-oriented thinking (Ciraci and Isidori, 2017). Much has been theorized on these issues but little has been done in the daily teaching practice in schools. The survey presented was conducted on two distinct samples of teachers. The first sample consists of 158 teachers in training for the specialization course for didactic support of pupil with disabilities in all school grades; the second sample is made up of 138 teachers already in service. A total of 296 subjects have been interviewed (272 are female). The aim was to investigate through an online questionnaire if teachers mastered the tools for collecting empirical data as well as if they incorporated the results of research carried out at school into their teaching and academic research. Most of the teachers from both groups claim to master and use the tools for the collection of empirical data, but declare that they have difficulties in structuring a research project in the classroom. It should also be noted that the areas in which they would like to develop a research activity is the “learning area” (study method, motivation, etc.) and the “relational and communication area”. A high percentage of respondents also shows that it is essential to strengthen research in the context of developing collaborative skills, useful both for building supportive and inclusive contexts, and for sharing empirical investigations with colleagues. We hope that our study will contribute to provide insights for professional training programs, and also to promote teaching practice based on empirical evidence.

The ongoing COVID-19 pandemic is leading to an increase of the global production of plastics since the use of personal protective equipment (PPEs, i.e. gloves, gowns, masks, packaging items), has become mandatory to prevent the spread of the virus. Plastic breaks down into micro/nano particles due to physical or chemical or biological actions into environment. Due to small dimensions, ubiquitous and persistent nature, the plastic particles represent a significant threat to ecosystems and can entry into food chains. Among the plastic polymers used for PPEs, polystyrene is less studied regarding its eco-geno-toxicity. This study aims to investigate acute, chronic and subchronic effects of the microplastic polystyrene beads (PS-MP, size 1.0 μm) on three freshwater species, the alga Raphidocelis subcapitata, the rotifer Brachionus calyciflorus, the crustacean Ceriodaphnia dubia and the benthic ostracod Heterocypris incongruens. Furthermore, the potential genotoxicity and the ROS production due to the PS-MP were also determined in C. dubia. Results revealed that the acute effects occurred at concentrations of PS-MP in the order of dozens of mg/L in B. calyciflorus and C. dubia and hundreds of mg/L in H. incongruens. Regarding long-term toxicity, increasing chronic effects with EC50s in the order of units (C. dubia), hundreds (B. calyciflorus) and thousands (R. subcapitata) of μg/L were observed. Both for acute and chronic/sub chronic toxicity, daphnids were more sensitive to polystyrene than ostracods. Moreover, when C. dubia neonates were exposed to the PS-MP, alterations in genetic material as well as the production of ROS occurred, starting from concentrations in the order of units of μg/L, probably due to inflammatory responses. At last, the risk quotient (RQ) as a measure of risk posed by PS-MPs in freshwater environment, was calculated obtaining a value of 7.2, higher than the threshold value of 1.

Nine 9,10-dihydrophenanthrenes, three phenanthrenes and a related pyrene have been isolated from the wetland plant Juncus acutus. The structures have been attributed by means of their spectral data and chemical correlation. 5-(1-Ethoxy-ethyl)-2-hydroxy-7-methoxy-1,8-dimethyl-9,10-dihydrophenanthrene and 5-(1-phytoxy-ethyl)-2-hydroxy-7-methoxy-1,8-dimethyl-9, 10-dihydrophenanthrene, 2,7-dihydroxy-1-methyl-5-vinylphenanthrene, 2,7-dimethoxy-1,6-dimethyl-5-vinylphenanthrene and 2,7-dihydroxy-1,6-dimethylpyrene are described for the first time. Many of the compounds showed in vitro phytotoxicity against Selenastrum capricornutum, a microalga used in aquatic tests. © 2002 Elsevier Science Ltd. All rights reserved.

Cannabidiol and cannabidivarin are phytocannabinoids produced by Cannabis indica and Cannabis sativa. Cannabidiol has been studied more extensively than its propyl analogue cannabidivarin. Therefore, we performed a battery of in vitro biological assays to compare the cytotoxic, antiradical and antibacterial activities of both cannabinoids. Potential mitochondrial metabolism alterations, DNA synthesis inhibition, and plasma membrane damage were studied by MTT assay, BrdU-ELISA and LDH assay of cancer and normal human cells exposed to cannabinoids. ABTS and DPPH assays were performed to observe the effects of the cannabinoids on free radicals. Microbial susceptibility tests were performed to study the activity of the cannabinoids in two bacterial species implicated in human infections, Escherichia coli and Staphylococcus aureus. The results showed that the cannabinoids induced medium levels of cytotoxicity in cancer and normal cells at concentrations ranging from 15.80 to 48.63 and from 31.89 to 151.70 µM, respectively, after 72 h of exposure. Cannabinoids did not exhibit a strong antioxidant capacity in scavenging ABTS or DPPH radicals. No evident differences were observed between the two cannabinoids in antimicrobial activity, except with respect to S. aureus, which showed greater susceptibility to cannabidiol than to cannabidivarin after 72 h of exposure.

The antibacterial and antioxidant activities of three methoxyphenol phytometabolites, eugenol, capsaicin, and vanillin, were determined. The in vitro antimicrobial potential was tested on three common foodborne pathogens (Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus) and three food spoilage bacteria (Shewanella putrefaciens, Brochothrix thermosphacta, and Lactobacillus plantarum). The antioxidant assays were carried out for studying the free radical scavenging capacity and the anti-lipoperoxidant activity. The results showed that eugenol and capsaicin were the most active against both pathogens and spoilage bacteria. S. aureus was one of the most affected strains (median concentration of growth inhibition: IC50 eugenol = 0.75 mM, IC50 capsaicin = 0.68 mM, IC50 vanillin = 1.38 mM). All phytochemicals slightly inhibited the growth of L. plantarum. Eugenol was the most active molecule in the antioxidant assays. Only in the oxygen radical absorbing capacity (ORAC) test did vanillin show an antioxidant activity comparable to eugenol (eugenol ORAC value = 2.12 ± 0.08, vanillin ORAC value = 1.81 ± 0.19). This study, comparing the antimicrobial and antioxidant activities of three guaiacol derivatives, enhances their use in future applications as food additives for contrasting both common pathogens and spoilage bacteria and for improving the shelf life of preserved food.

Wastewater irrigation of crops may be effective to avoid depletion (about 70%) of freshwater resources. However, the use of reclaimed waters containing persistent microcontaminants such as antineoplastic drugs is of high environmental concern. These active compounds may affect human health with potentially severe adverse effects. To better understand the impact on human health following irrigation of crops with reused contaminated waters, we exposed four edible plants, Brassica rapa, Lactuca sativa, Raphanus sativus, and Triticum durum, to two commonly used antitumoral drugs: 5-fluorouracil (5-FU), and Cisplatin (CDDP), using metabolomics as a potential functional genomics tool to combine with genotoxicity experiments. The metabolome of the treated and untreated plants was analysed to detect biochemical alterations associated to the exposure, and the potential genotoxic damage related to human exposure to the treated plants was evaluated using the comet assay in human lymphocytes, which are characterized by high sensitivity to genotoxic substances. The edible species were able to assimilate 5-FU and CDDP during the treatment, affecting the biochemical pathways of these plants with subsequent metabolome modifications. These metabolic alterations differed according to the specific species used for the test. Furthermore, all vegetables treated with two concentrations of the selected drugs (10 and 100 μg/L) caused significant (p < 0.0001) genotoxic damage in the cells of the immune system at a higher level than in the lymphocytes directly exposed to single antineoplastic drugs.

Capsaicin is a spicy capsaicinoid, produced as secondary metabolite by Capsicum fruits. This alkaloid has been used for years in folk medicine for its analgesic and antinflammatory properties although most data is referred to the raw fruit. In this study, the antiradical activity of the pure capsaicin has been studied using 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) assays as well as its antiproliferative activity, using MTT assay, against two human tumour cell lines, the colorectal Caco-2 and the oesophageal OE19 cells. Furthermore, the antiproliferative activity observed on tumoral cells was compared with that of the human normal-like fibroblast cell line TelCOFS02MA. In addition, the apoptotic activity was evaluated using TUNEL assay. A higher radical scavenging activity was observed against ABTS radical cation than DPPH. Capsaicin showed also a higher cytotoxicity against cancer cells than normal-like cells with Selectivity index values greater than 2 at 72h. Capsaicin induced apoptosis especially in OE19 cell line.

Anticancer drugs are among the most toxic chemicals, which are commercially produced; therefore, their release in aquatic ecosystems raised concerns in regard to potential adverse effects. This article describes the results of risk assessments concerning their environmental safety, which are based on data generated in the frame of a coordinated EU project (“Cytothreat”). Eight research institutions participated in the project and four widely used anticancer drugs with different mechanisms of therapeutic action (5-fluorouracil 5FU, cisplatin CDDP, imatinib mesylate IM and etoposide ET) were tested in a variety of indicator organisms (cyanobacteria, algae, higher plants, rotifers, crustacea, fish and also in human and fish derived cell lines) in acute/subacute/chronic toxicity assays. Furthermore, genotoxic effects in micronucleus assays, single cell gel electrophoresis experiments and γH2AX tests were studied in plants, crustacea, fish and in various cell lines. We used the results to calculate the predicted no effect concentrations (PNEC) and risk quotients (RQ) by comparing PNEC with predicted environmental concentrations (PEC values) and measured concentrations (MEC) in wastewaters. The most sensitive species in experiments concerning acute toxic and long term effects were in general crustacea (daphnids) after chronic treatment the most pronounced effects were detected with IM followed by CDDP and 5FU. Comparisons between PNEC and PEC values indicate that it is unlikely that the release of these drugs in the aquatic environments leads to adverse effects (RQ values < 1). However, when the assessments were performed with MEC found in highly contaminated municipal wastewaters and hospital effluents, RQ values were obtained which are indicative for moderate adverse effects of IM. Calculations with data from genotoxicity experiments and PEC values are indicative for increased RQ values for all compounds except ET. The most sensitive species were fish (Danio rerio) which were highly responsive towards 5FU and daphnids which were sensitive towards CDDP and IM. When environmental data (from waste waters) were used for the calculations, high RQ values (>100) were obtained for CDDP and IM. These overall conclusions were not substantially altered when the effects of other frequently used cytostatic drugs and combined effects of mixtures of anticancer drugs were taken into consideration. The results of these assessments underline the importance of efficient removal of these chemicals by improved sewage treatment strategies and the need for further investigations of adverse the long term effects of cytostatics in aquatic biota as a consequence of damage of the genetic material in highly sensitive species.

International audience; The photochemical behavior of etodolac was investigated under various irradiation conditions. Kinetic data were obtained after irradiation of 10− 4 M aqueous solutions by UVB, UVA and direct exposure to sunlight. The Xenon lamp irradiation was used in order to determine the photodegradation quantum yield under sun-simulated condition (ϕsun). The value was determined to be = 0.10 ± 0.01. In order to obtain photoproducts and for mechanistic purposes, experiments were carried out on more concentrated solutions by exposure to sunlight and to UVA and UVB lamps. The drug underwent photooxidative processes following an initial oxygen addition to the double bond of the five membered ring and was mainly converted into a spiro compound and a macrolactam. Ecotoxicity tests were performed on etodolac, its photostable spiro derivative and its sunlight irradiation mixture on two different aquatic trophic levels, plants (algae) and invertebrates (rotifers and crustaceans). Mutagenesis and genotoxicity were detected on bacterial strains. The results showed that only etodolac had long term effects on rotifers although at concentrations far from environmental detection values. A mutagenic and genotoxic potential was found for its derivative.

Pipemidic acid (HPPA) is a quinolone antibacterial agent used mostly to treat gram-negative infections of the urinary tract, but its therapeutic use is limited because of its low solubility. Thus, to improve drug solubility, natural cyclodextrins (CDs) are used for their ability of including guest molecules within their cavities. The aim of this work was to evaluate the antibacterial activity and the preliminary anticancer activity of HPPA included into Heptakis (2,3,6-tri-O-methyl)-β-cyclodextrin (TRIMEB) as a possible approach for a new innovative formulation. The inclusion complex of HPPA with TRIMEB was prepared in solid state by the kneading method and confirmed by FT-IR and powered X-ray diffraction. The association in aqueous solutions of pipemidic acid with TRIMEB was investigated by UV-Vis spectroscopy. Job’s plots have been drawn by UV-visible spectroscopy to confirm the 1:1 stoichiometry of the host–guest assembly. The antibacterial activity of HPPA, TRIMEB and of their complex was tested on Escherichia coli, Pseudomonas aeruginosa, and Staphilococcus aureus. The complex was able to increase 47.36% of the median antibacterial activity of the free HPPA against E. coli (IC50 = 249 µM vs. 473 µM). Furthermore, these samples were tested on HepG-2 and MCF-7. After 72 h, the median tumoral cytotoxicity exerted by the complex was increased by 78.08% and 94.27% for HepG-2 and MCF-7 respectively, showing a stronger bioactivity of the complex than the single HAPPA.

Sunlight exposure of aqueous suspensions of carboxin (1) causes its phototransformation to sulfoxide 2 and minor components. Similar effects are observed in the presence of humic acid or nitrate or at different pH values. Photoproducts 2-9 were isolated by chromatographic techniques and/or identified by spectroscopic means. Carboxin 1 and its main photoproduct sulfoxide 2 were tested to evaluate acute toxicity to primary consumers typical of the aquatic environment: the rotifer Brachionus calyciflorus and two crustaceans, Daphnia magna and Thamnocephalus platyurus. Chronic tests comprised a producer, the alga Pseudokirchneriella subcapitata, and a consumer, the crustacean Ceriodaphnia dubia.

Seven natural 9,10-dihydrophenanthrenes were isolated from the common reed Juncus effusus by means of chromatographic processes and identified by spectroscopic means. Furthermore, mimics of natural isolated compounds were synthesized to try to evaluate the influence of functional groups on the dihydrophenanthrene skeleton. Syntheses of compounds were based on the cross-coupling of 1-(2-iodo-5-methoxy)phenyl-ethanol with variously substituted iodobenzenes by zerovalent nickel. All the chemicals were tested to evaluate their effects on freshwater organisms from different trophic levels. Toxicity tests were performed on reducers (the bacterium Escherichia coli); producers (the alga Raphidocelis subcapitata, previously known as Selenastrum capricornutum); and consumers including a rotifer (Brachionus calyciflorus), a cladoceran (Daphnia pulex), and an anostracan (Thamnocephalus platyurus). Results suggested no one organism was uniquely sensitive to the chemicals tested. Toxicity depended on the kind and position of substituents on the aromatic skeleton.

Caffeine is ubiquitous in surface and ground waters and it has been proposed as a marker of the anthropogenic pressure on the environment. Sewage treatment plants based on active sludges seem to be not very efficient in its complete removal from effluents while addnl. disinfection treatments by chlorination are able to do it. In a simulation of the chlorination step herein we report that caffeine is transformed in six byproducts: 8-???chlorocaffeine, 1,???3-???dimethyl-???5-???azabarbituric acid, N,???N'-???dimethylparabanic acid, N,???N'-???dimethyloxalamide, N-???methylurea and N,???N'-???dimethylurea. The ecotoxicity of caffeine and identified compds. was evaluated on the rotifer Brachionus calyciflorus and the alga Pseudokirchneriella subcapitata to assess acute and chronic toxicity, while SOS Chromotest and Ames Test were used to detect the genotoxic potential of the investigated compds. Moreover, we assessed the possible antigenotoxic effect of the selected compds. using SOS Chromotest after co-???incubation with the std. genotoxin, 4-???nitroquinoline 1-???oxide. Chronic exposure to these compds. caused inhibition of growth population on the rotifer while the algae seemed to be unaffected. Results indicated that caffeine (1)???, N,???N'-???dimethyloxamide (4) and N,???N'-???dimethylparabanic acid (5) reduced ??-???galactosidase activity in comparison with pos. control, both at 1 and 5 mg???/L of 4-???NQNO with a good dose-???response.

Nicotine, the main alkaloid of tobacco, is a non-prescription drug to which all members of a tobacco-smoking society are exposed either through direct smoke inhalation or through second-hand passive 'smoking'. Nicotine is also commercially available in some pharmaceutical products and is used worldwide as a botanical insecticide in agriculture. Nicotine dynamics in indoor and outdoor environments as well as the human excretions and the manufacturing process are responsible for its entry in the environment through municipal and industrial wastewater discharges. The presence of nicotine in surface and ground waters points out that it survives a conventional treatment process and persists in potable-water supplies. Complete removal of nicotine is instead reported when additional chlorination steps are used. In this paper a simulation of STP chlorination of nicotine and a genotoxic evaluation of its main degradation products are reported. Under laboratory conditions removal of nicotine seems not to be due to mineralization but to transformation in oxidized and chlorinated products. The by-products have been isolated after fractionation by diverse chromatographic procedures and their structures determined using mass spectrometry and H-1 and C-13 NMR spectroscopy. Preliminary genotoxic SOS Chromotests with Escherichia coil PQ37 evidence no toxicity of the products. (C) 2012 Elsevier B.V. All rights reserved.

This study was designed to assess the overall ecotoxicity of ranitidine, a histamine H2-receptor antagonist that inhibits stomach acid production. Hence, in addition to ranitidine, its main two photoderivatives, obtained by solar simulator irradiation in water, were investigated. The photoproducts were identified by their physical features. Bioassays were performed on rotifers and microcrustaceans to assess acute and chronic toxicity, while SOS Chromotest and Ames test were utilized to detect the genotoxic potential of the investigated compounds. The results showed that ranitidine did not show any acute toxicity at the highest concentration tested (100 mg/L) for all the organisms utilized in the bioassays. Chronic exposure to these compounds caused inhibition of growth population on rotifers and crustaceans. Genotoxic and mutagenic effects were especially found for one photoproduct suggesting that transformation products, as frequently demonstrated, may show effects higher than the respective parental compound. Keywords: Ranitidine, Phototransformation, Toxicity testing, Genotoxicity, Mutagenesis

Pharmaceutical products for humans and animals, as well as their related metabolites end up in the aquatic environment after use. Recent investigations show that concentrations of pharmaceuticals are detectable in the order of ng/l-μg/l in municipal wastewater, groundwater and also drinking water. Little is known about the effects, and the hazard of long-term exposure to low concentrations of pharmaceuticals for non-target aquatic organisms. This study was designed to assess the ecotoxicity of furosemide, a potent diuretic agent, and its photoproduct in the aquatic environment. Bioassays were performed on bacteria, algae, rotifers and microcrustaceans to assess acute and chronic toxicity, while the SOS Chromotest and the Ames test were utilized to detect the genotoxic potential of the investigated compounds. A first approach to risk characterization was to calculate the environmental impact of furosemide by measured environmental concentration and predicted no effect concentration ratio (MEC/PNEC). To do so we used occurrence data reported in the literature and our toxicity results. The results showed that acute toxicity was in the order of mg/l for the crustaceans and absent for bacteria and rotifers. Chronic exposure to these compounds caused inhibition of growth population on the consumers, while the algae did not seem to be affected. A mutagenic potential was found for the photoproduct compared to the parental compound suggesting that byproducts ought to be considered in the environmental assessment of drugs. The risk calculated for furosemide suggested its harmlessness on the aquatic compartment. © 2005 Elsevier Ltd. All rights reserved.

Olive oil mill wastewaters (OMWs) show significant polluting properties due to their content of organic substances, and because of their high toxicity toward several biological systems. Wastewaters' toxicity has been attributed to their phenolic constituents. A chemical study of wastewaters from a Ligurian oil mill characterized phenolic products such as 1,2-dihydroxybenzene (catechol), derivatives of benzoic acid, phenylacetic acid, phenylethanol, and cinnamic acid. The OMWs were fractioned by ultrafiltration and reverse osmosis techniques and tested for toxicity on aquatic organisms from different trophic levels: the alga Pseudokirchneriella subcapitata (formerly known as Selenastrum capricorntum); the rotifer Brachionus calyciflorus; and two crustaceans, the cladoceran Daphnia magna and the anostracan Thamnocephalus platyurus. The fraction most toxic to the test organisms was that from reverse osmosis containing compounds of low molecular weight (

Light exposure of aqueous suspensions of prednisolone and dexamethasone causes their partial phototransformation. The photoproducts, isolated by chromatographic techniques, have been identified by spectroscopic means. Prednisolone, dexamethasone and their photoproducts have been tested to evaluate their acute and chronic toxic effects on some freshwater chain organisms. The rotifer Brachionus calyciflorus and the crustaceans Thamnocephalus platyurus and Daphnia magna were chosen to perform acute toxicity tests, while the alga Pseudokircheneriella subcapitata (formerly known as Selenastrum capricornutum) and the crustacean Ceriodaphnia dubia to perform chronic tests. The photochemical derivatives are more toxic than the parent compounds. Generally low acute toxicity was found. Chronic exposure to this class of pharmaceuticals caused inhibition of growth population on the freshwater crustacean C. dubia while the alga P. subcapitata seems to be less affected by the presence of these drugs. © 2003 Elsevier Ltd. All rights reserved.

Solar simulator irradiation of an aqueous suspension of prednisone, a widely prescribed drug, produces seven photochemical derivatives. The compounds have been identified on the basis of their physical features. All the chemicals have been tested to evaluate their toxic effects on freshwater organisms from different trophic levels. The rotifer Brachionus calyciflorus and two crustaceans, the cladoceran Daphnia magna and the anostracan Thamnocephalus platyurus, were used to perform acute toxicity tests. Chronic toxicity tests have been performed on the alga Pseudokirchneriella subcapitata (formerly known as Selenastrum capricornutum) and the crustacean Ceriodaphnia dubia. The results showed low acute and chronic toxicity of prednisone. Some of the photoproducts had high toxic effects on C. dubia.

Sixfurano-ent-labdanes,19-acetoxy-15,16-epoxy-8(17),13(16),14-ent-labdatrien-20-al,15,16-epoxy-12-oxo-8(17),13(16),14-ent-lab-datrien-20,19-olide,12(S)-hydroxy-15,16-epoxy-8(17),13(16),14-ent-labdatrien-20,19-olide,10a,19-dihydroxy-15,16-epoxy-8(17),13(16),14-nor-ent-labdatriene, 19,20-dihydroxy-15,16-epoxy-8(17),13(16),14-ent-labdatriene, 15,16-epoxy-12-oxo-8(17),13(16),14-ent-labdatrien-19,20-olide,wereisolated,togetherwiththeknownpotamogetonin,fromtheaquaticplantPotamogeton natans.Theirstructuresweredeterminedonthebasisoftheirchemicalandspectraldata.ThecompoundsshowedinvitrophytotoxicityagainstRaphidocelis subcapitata,amicroalgausedinaquatictests.# 2001ElsevierScienceLtd.Allrightsreserved. Keywords: Potamogeton natans;Potamogetonaceae;Raphidocelis subcapitata;ent-Labdanes;Furano-diterpenes;Antialgalactivity;Spectroscopicanalysis 1. IntroductionChemical interactions between aquatic plants andmicroalgaeplayanimportantroleinaquaticecosystemssincetheproductionofmetabolitesbythemacrophytesmightcontrolthealgalgrowth(Fitzgerald,1969).Has-lerandJones(1949)observedthatthealgalpopulationdecreasedwhenplantsbelongingtothePotamogetona-ceaewerepresentintheaquaticsystems.Theabilityofsomenaturalproductstoinhibittheinvitrodevelop-mentofthemicroalgaehasbeenreportedcopiously(DellaGrecaetal.,1996andref.cit.)andinapreviouspaperweshowedthatbioactiveproductsisolatedfromPistia stratiotes arereleasedintotheenvironment(Del-laGrecaetal.,1999).Recently we investigated Potamogeton natans,afreshwater Potamogetonacea, distributed throughouttheMediterraneanbasin(Cangianoetal.,2001).Thephytochemicalstudyhasalreadyledtotheisolationofseveralditerpenelactones,someofthemshowingahighantialgalactivity.2. Results and discussionInpursuingthechemicalinvestigationofP. natans,weisolatedthepotamogetonin(1)(Smithetal.,1976)andsixnewfuranoident-labdanes2–7,identifiedbytheirspectroscopicfeatures.Spectraldataofcompound1 wereingoodagreementwiththoseoftherevisedstructureofpotamogetonin(HasegawaandHirose,1983),butthereweresomedif-ferencesinthechemicalshiftassignments.Ourassign-ments,basedon2DNMRexperiments(H–HCOSY,DEPT,HMBC,HMQC,andNOESY),arereportedinTable 1. The methylene signals at 36.0 and 41.8,ascribedtoC-3andC-1,aswellasthoseat 23.7and25.7,ascribedtoC-11andC-12,wereexchangedonthebasisoftheHMBCexperiment.Infactthesignalat36.1,showinginteractionwiththeH-2at 1.70,wasattributedtotheC-1,whilethesignalat 41.2,corre-latedwiththeH-1,H-18andH-19,wasattributedtotheC-3.Thesamespectrumshowedtheinteractionofthecarbonat 23.8withtheH-11,H-14andH-16sig-nalsandofthecarbonat 25.8withtheH-9andH-12.TheseobservationsareinagreementwiththeexchangeofthecarbonassignmentsatC-11andC-12.The EI mass spectrum of compound 2 showed amolecular ion at m/z 358, which, together with the

Seven ent-labdane diterpenes, have been isolated from Ruppia maritima. The structures 15,16-epoxy-ent-labda-8(17),13(16),14trien- 19-al; 15,16-epoxy-ent-labda-8 (17), 13(16), 14-trien- 19-ol acetate; methyl 15,16-epoxy- 12-oxo-ent-labda-8 (17), 13 (16), 14-trien-19-oate; 15,16-epoxy-ent-labd-8 (17), 13E-dien- 15-ol and 13-oxo- 15,16-bis-nor-ent-labd-8 (17)-ene have been assigned to the five new compounds by spectroscopic means and chemical correlations. The phytotoxicity of the diterpenes has been assessed using the alga Selenastrum capricornutum as organism test. (C) 2000 Elsevier Science Ltd.