Marina Isidori

Toxicity identification evaluation of leachates from municipal solid waste landfills: a multispecies approach

The toxicity of leachates from two municipal solid waste (MSW) landfills in Southern Italy was characterized using a toxicity identification evaluation procedure. The chemical and physical fractionation techniques were: pH adjustment, pH adjustment/filtration, pH adjustment/C(18) solid phase extraction, graduated pH and EDTA chelation. All the samples exhibited acute toxicity towards the bacterium Vibrio fischeri, the freshwater rotifer Brachionus calyciflorus and the freshwater crustaceans Thamnocephalus platyurus and Daphnia magna. Statistical techniques were used to determine the discriminatory power and the toxicity detection capacity of the different assays and to choose a minimal battery of tests for the toxicity identification of leachates. Toxicity was closely associated with pH, generally increasing at higher pH levels and decliming at lower ones. Furthermore, results showed that toxicants could be characterized as cations, basic chemicals, suspended solids and apolar compounds.

Acute and chronic toxicity of six anticancer drugs on rotifers and crustaceans.

The growing use of cytostatic drugs is gaining relevance as an environmental concern. Environmental and distribution studies are increasing due to the development of accurate analytical methods, whereas ecotoxicological studies are still lacking. The aim of the present study was to investigate the acute and chronic toxicity of six cytostatics (5-fluorouracil, capecitabine, cisplatin, doxorubicin, etoposide, and imatinib) belonging to five classes of Anatomical Therapeutic Classification (ATC) on primary consumers of the aquatic chain (Daphnia magna, Ceriodaphnia dubia, Brachionus calyciflorus, and Thamnocephalus platyurus). Acute ecotoxicological effects occurred at concentrations in the order of mgL(-)(1), higher than those predicted in the environment, and the most acutely toxic drugs among those tested were cisplatin and doxorubicin for most aquatic organisms. For chronic toxicity, cisplatin and 5-fluorouracil showed the highest toxic potential in all test organisms, inducing 50% reproduction inhibition in crustaceans at concentrations on the order of μgL(-)(1). Rotifers were less susceptible to these pharmaceuticals. On the basis of chronic results, the low effective concentrations suggest a potential environmental risk of cytostatics. Thus, this study could be an important starting point for establishing the real environmental impact of these substances.

Phenanthrenoids from the wetland Juncus acutus

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.

Chemical Constituents of the Aquatic Plant Schoenoplectus lacustris: Evaluation of Phytotoxic Effects on the Green Alga Selenastrum capricornutum

Forty-nine secondary metabolites were isolated from aqueous and alcoholic extracts of the aquatic plant Shoenoplectus lacustris. All compounds were characterized based on spectroscopic data. Eleven free and glycosylated low-molecular polyphenols, 17 cinnamic acid and dihydrocinnamic acid derivatives, 11 flavonoids, and 10 C13nor-isoprenoids were identified. The structure of the new compound, 1-benzoyl-glycerol-2-α-l-arabinopyranoside, was elucidated by 2D NMR experiments (COSY, HSQC, HMBC, NOESY). To evaluate potential phytotoxic effects, all compounds were tested on the green alga Selenastrumcapricornutum, a unicellular organism commonly used in tests of toxicity as a bioindicator of eutrophic sites. The most active compound was (−)-catechin, showing an inhibition similar to that of the algaecide CuSO4.

Antialgal ent-labdane diterpenes from Ruppia maritima

Seven ent-labdane diterpenes have been isolated from Ruppia maritima. The structures 15,16-epoxy-ent-labda-8(17),13(16),14-trien-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.

Antialgal furano-diterpenes from Potamogeton natans L.

Six furano-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-labdatrien-20,19-olide, 12(S)-hydroxy-15,16-epoxy-8(17),13(16),14-ent-labdatrien-20,19-olide, 10alpha,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, were isolated, together with the known potamogetonin, from the aquatic plant Potamogeton natans. Their structures were determined on the basis of their chemical and spectral data. The compounds showed in vitro phytotoxicity against Raphidocelis subcapitata, a microalga used in aquatic tests.

Effect of ent-labdane diterpenes from Potamogetonaceae on Selenastrum capricornutum and other aquatic organisms.

Twenty ent-labdane diterpenes, isolated from the aquatic plants Ruppia maritima and Potamogeton natans, were tested to detect their effects on aquatic organisms from different trophic levels. Toxicity tests were performed on aquatic producers (the alga Selenastrum capricornutum), and consumers including a rotifer (Brachionus calyciflorus), a cladoceran crustacean (Daphnia magna), and two anostracan crustaceans (Thamnocephalus platyurus and Artemia salina). Furano-ent-labdanes exhibited high toxicity toward all of these organisms. 15,16-Epoxy-12(S)-hydroxy-8(17),13(16),14-ent-labdatrien-20,19-olide had a high toxicity only toward the algae and the rotifers. It was inactive for the crustaceans.

β-Cyclodextrin Inclusion Complex to Improve Physicochemical Properties of Pipemidic Acid: Characterization and Bioactivity Evaluation

The aptitude of cyclodextrins (CDs) to form host-guest complexes has prompted an increase in the development of new drug formulations. In this study, the inclusion complexes of pipemidic acid (HPPA), a therapeutic agent for urinary tract infections, with native β-CD were prepared in solid state by kneading method and confirmed by FT-IR and 1H NMR. The inclusion complex formation was also characterized in aqueous solution at different pH via UV-Vis titration and phase solubility studies obtaining the stability constant. The 1:1 stoichiometry was established by a Job plot and the inclusion mechanism was clarified using docking experiments. Finally, the antibacterial activity of HPPA and its inclusion complex was tested on P. aeruginosa, E. coli and S. aureus to determine the respective EC50s and EC90s. The results showed that the antibacterial activity of HPPA:β-CD against E. coli and S. aureus is higher than that of HPPA. Furthermore, HPPA and HPPA:β-CD, tested on human hepatoblastoma HepG2 and MCF-7 cell lines by MTT assay, exhibited, for the first time, antitumor activities, and the complex revealed a higher activity than that of HPPA. The use of β-CD allows an increase in the aqueous solubility of the drug, its bioavailability and then its bioactivity.

Toxicity of exposure to binary mixtures of four anti-neoplastic drugs in Daphnia magna and Ceriodaphnia dubia.

Anticancer drugs, interfering with DNA in every living organism, may pose a threat to aquatic environment, even more when they occur as complex mixtures. We investigated the combined long term toxic potential of four anti-neoplastic drugs (5-fluorouracil [5-FU], cisplatin [CDDP], etoposide [ET] and imatinib mesylate [IM]) testing their binary mixtures on two primary consumers of the freshwater aquatic chain with close phylogenetic relationship: Daphnia magna and Ceriodaphnia dubia. The combined toxicities were assessed using two distinct effect sizes that should be observed if Bliss independence holds. Direct statistical comparison by analysis of variance of single and combined toxicities under the assumption of Bliss independence allowed to accept or reject the independency hypothesis. Independency was confirmed for all mixtures both in D. magna and in C. dubia, except for IM+ ET and IM+CDDP in D. magna and for ET+CDDP and ET+5-FU in C. dubia which at the highest concentrations showed an antagonistic interaction. A synergic tendency was found testing IM+CDDP on C. dubia at the lowest concentration selected. Thus, the chronic ecotoxicological data evaluated in this study show not only a potential environmental risk of anticancer drugs, especially considering their potential synergistic effects, but also the necessity to integrate statistical models with experimental data to establish the real environmental impact of such compounds.

Benzocoumarins from the rhizomes of Juncus acutus

Abstract 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.