Degradation of Polylactic Acid/Polypropylene Carbonate Films in Soil and Phosphate Buffer and Their Potential Usefulness in Agriculture and Agrochemistry.

Blends of poly(lactic acid) (PLA) with poly(propylene carbonate) (PPC) are currently in the phase of intensive study due to their promising properties and environmentally friendly features. Intensive study and further commercialization of PPC-based polymers or their blends, as usual, will soon face the problem of their waste occurring in the environment, including soil. For this reason, it is worth comprehensively studying the degradation rate of these polymers over a long period of time in soil and, for comparison, in phosphate buffer to understand the difference in this process and evaluate the potential application of such materials toward agrochemical and agricultural purposes. The degradation rate of the samples was generally accompanied by weight loss and a decrease in molecular weight, which was facilitated by the presence of PPC. The incubation of the samples in the aqueous media yielded greater surface erosions compared to the degradation in soil, which was attributed to the leaching of the low molecular degradation species out of the foils. The phytotoxicity study confirmed the no toxic impact of the PPC on tested plants, indicating it as a "green" material, which is crucial information for further, more comprehensive study of this polymer toward any type of sustainable application.

Ecotoxicological assessment of magnetite and magnetite/Ag nanoparticles on terrestrial and aquatic biota from different trophic levels.

The aim of the study is an ecotoxicological assessment of magnetite iron oxide-based nanoparticles (NPs), which have risen in popularity in the last decade, on selected terrestrial and aquatic organisms from various levels of the food chain. In the presented study various organisms, from both the terrestrial and aquatic environment, were used as targets for the assessment of NPs ecotoxicity. Plants (radish, oat), marine bacteria (A. fischeri) and crustacean (H. incongruens) were used to represent producers, decomposers, and consumers, respectively. It was found that examined NPs were harmful (to a different degree) to biota from three different trophic levels. Physicochemical characterization (size/morphology, crystallinity, composition, and magnetic properties) of the tested nanoparticles was performed by: transmission electron microscopy, X-ray diffraction, energy dispersive spectroscopy, and Mossbauer spectroscopy, respectively. Phytotoxicity was evaluated according to the OECD 208 Guideline, while acute and chronic toxicity of NPs was conducted using bioassays employing bacteria and crustacea, respectively. The phytotoxicity of all investigated iron oxide-based NPs was dependent on concentration and type of NPs formulation and was measured via biomass, seed germination, root length, shoot height, and content of plant pigments. Increasing the concentration of NPs increased phytotoxicity and mortality of aquatic organisms. Ecotoxicity of iron oxide/silver was dependent on the size and content of silver. Iron oxide NPs coated with nanosilver in a percentage ratio of 69/31 were found to be the most toxic on tested terrestrial and aquatic biota.

From high oleic vegetable oils to hydrophobic starch derivatives: II. Physicochemical, processing and environmental properties.

Medium-substituted esters of starch and higher fatty acids, structurally identified in the first part of paper were subjected to further analyses, mainly to check application potential. In order to determine the possibility of using the esters in the packaging industry, the glycerol-plasticized starch esters were extruded on a single screw extruder in the form of a film. The mechanical properties tests consisted of tensile and tear strength. Hydrophobicity, water absorption and oil absorption were checked as the processing and functional properties. Environmental tests, such as phytotoxicity on monocotyledonous and dicotyledonous plants and biodegradability in soil under strictly controlled conditions of the vegetation hall were carried out. Esterification increased the hydrophobicity of the starch and the tensile and tear strength, without losing important environmental features such as biodegradability and non-toxicity. The obtained polymer materials give hope for their use in the production of new ecofriendly and biodegradable packaging.

Ecotoxicological effects of new C-substituted derivatives of N-phosphonomethylglycine (glyphosate) and their preliminary evaluation towards herbicidal application in agriculture.

In this paper, comparison of ecotoxicological and herbicidal effect of newly synthesized N­[(phosphono)(aryl)methyl]glycines 1a-g (C-substituted glyphosate derivatives) with pure glyphosate (N-phosphonomethylglycine) (2) was demonstrated. All of tested glyphosate derivatives (1a-g) in contrast to glyphosate, were found to be completely safe for oat (Avena sativa) and classified as not harmful for marine bacteria Aliivibrio fischeri. Compounds 1a-g were also found rather harmless to radish (Raphanus sativus) as compared to N-phosphonomethylglycine, but they were moderately toxic against freshwater crustaceans Heterocypris incongruens. One of synthesized compounds, namely N-[(phosphono)(4-hydroxyphenyl)methyl]glycine (1f) was found to possess stronger herbicidal properties against gallant soldier (Galinsoga parviflora) and common sorrel (Rumex acetosa) when compared to pure glyphosate and demonstrated total death of these weeds being ranked 1 in the European Weed Research Council (EWRC) scale. Considering lower phytotoxicity of compound 1f against cultivated plants and tested microorganisms when compared to pure glyphosate, this aminophosphonate may be good candidate for further, more comprehensive study toward its agrochemical application, especially that this active agent demonstrated much stronger herbicidal properties than N-phosphonomethylglycine.

The Effect of New Thiophene-Derived Diphenyl Aminophosphonates on Growth of Terrestrial Plants.

The aim of this work was to evaluate the impact of the thiophene-derived aminophosphonates 1-6 on seedling emergence and growth of monocotyledonous oat (Avena sativa) and dicotyledonous radish (Raphanus sativus L.), and phytotoxicity against three persistent and resistant weeds (Galinsoga parviflora Cav., Rumex acetosa L., and Chenopodium album). Aminophosphonates 1-6 have never been described in the literature. The phytotoxicity of tested aminophosphonates toward their potential application as soil-applied herbicides was evaluated according to the OECD (Organization for Economic and Cooperation Development Publishing) 208 Guideline. In addition, their ecotoxicological impact on crustaceans Heterocypris incongruens and bacteria Aliivibrio fischeri was measured using the OSTRACODTOXKITTM and Microtox® tests. Obtained results showed that none of the tested compounds were found sufficiently phytotoxic and none of them have any herbicidal potential. None of the tested compounds showed important toxicity against Aliivibrio fischeri but they should be considered as slightly harmful. Harmful impacts of compounds 1-6 on Heterocypris incongruens were found to be significant.

Ecotoxicological impact of selected polyethylenimines toward their potential application as nitrogen fertilizers with prolonged activity.

Poly(2-oxazoline) polymers have found extensive application in the preparation of microcapsules for biomedical purposes. However, there is a scarcity of information related to their ecotoxicological assessment. Therefore, in this study, we focused on the ecotoxicity of selected polyethylenimines (PEIs) including poly(2-ethyl-2-oxazoline) (PEtOx) as an N-acyl-substituted PEI, linear polyethylenimine (LPEI) and branched polyethylenimine (BPEI). Oat (a monocotyledon) (Avena sativa) and radish (a dicotyledon) (Raphanus sativus) were selected as the representative plants, which are recommended by the Organization for Economic Cooperation and Development (OECD) 208 as the standard to test for plant growth. Shoot and root length, fresh and dry matter, level of total nitrogen in green parts of the plants, as well as total chlorophyll and carotenoids were determined. Phytotoxicity of all the tested parameters was dependent on the concentration of the examined polymers in the soil as well as on the time of their incubation in the soil. According to our results, the amount of nitrogen in green parts of the plants was increased compared to the control plants, which revealed the uptake of the plant-available form of nitrogen released from the tested PEIs. This was especially true for the plants treated with LPEI. Ecotoxicological impact of the incubated polymers in the soil against marine bacteria Allivibrio fischeri proved that, the all tested polyethylenimines may be classified as not harmful to aquatic microorganisms.

Hazardous ecotoxicological impact of two commonly used nitrofuran-derived antibacterial drugs: Furazolidone and nitrofurantoin.

This paper discusses the impact of two nitrofuran-derived drugs, namely furazolidone and nitrofurantoin on growth of oat and common radish as well as their impact on bacteria Allivibrio fischeri and crustaceans Heterocypris incongruens. Results indicated that both compounds were highly phytotoxic for radish (R. sativus) being simultaneously nearly not harmful for oat (A. sativa). Growing inhibition of shoots, roots, fresh matter and photosynthetic pigments is correlated with growing concentration of drugs in soil. Ecotoxicological impact of both compounds on model luminescence bacteria Aliivibrio fischeri and freshwater crustaceans Heterocypris incongruens as a representative organisms of two different level of food chain, is also reported herein, and the obtained data show significant toxicity against these two organisms. Basing on obtained results, it was concluded that both nitrofuran drugs in case of distribution through environment, by improper utilisation after use or unplanned environmental intoxication with unused drugs may cause serious environmental problems and therefore both should be handled with a reasonable care at any step of their production or utilisation.

Effect of New Thiophene-Derived Aminophosphonic Derivatives on Growth of Terrestrial Plants. Part 2. Their Ecotoxicological Impact and Phytotoxicity Test Toward Herbicidal Application in Agriculture.

Background: The aim of this work was to evaluate phytotoxicity of the thiophene derivatives against three persistent weeds of a high degree of resistance (Galinsoga parviflora Cav., Rumex acetosa L., and Chenopodium album) as well as their ecotoxicological impact on Heterocypris incongruens. In addition, Aliivibrio fischeri was measured. Two of eight described aminophosphonates, namely dimethyl N-(2-methoxyphenyl)amino(2-thienyl)methylphosphonate (2d) and dimethyl N-(tert-butyl)- (2-thienyl)methylphosphonate (2h), have never been reported before. Methods: The phytotoxicity of tested aminophosphonates toward their potential application as soil-applied herbicides was evaluated according to the OECD 208 Guideline. Ecotoxicological properties of investigated compounds were made using the OSTRACODTOXKITTM and Microtox® tests. Results: Obtained results showed that four aminophosphonates have interesting herbicidal properties and N-(2-methylphenyl)amino- (2-thienyl)methylphosphonate (2a) was found to kill efficiently the most resistant plant Chenopodium album. None of the tested compounds showed important toxicity against Aliivibrio fischeri. However, their toxic impact on Heterocypris incongruens was significantly elevated. Conclusions: The aminophosphonate 2a showed herbicidal potential and it is not toxic against tested bacteria (EC50 over 1000 mg/L). It was found to be moderately toxic against ostracods [mortality 48% at 10 mg/kg of soil dry weight (s.d.w.)] and this problem should be solved by the use of the controlled release from a polymeric carrier.

Novel (5-nitrofurfuryl)-substituted esters of phosphonoglycine - Their synthesis and phyto- and ecotoxicological properties.

Since aminophosphonate-based herbicides like glyphosate are currently one of the most popular and widely applied active agent in agrochemistry, there is an urgent need for searching new compounds among this family with potential herbicidal activity, but exhibiting low toxicity against surrounding environment. Six new (5-nitrofurfuryl)-derived aminophosphonates were synthesized for the first time and apart from the only one example of N-benzylamino(5-nitrofuryl)-methylphosphonic acid, it was the first time in the history, when this class of compounds was prepared. Their prospective and real biological properties have been followed up by evaluation of their preliminary ecotoxicology. They have been then investigated in aspect of their phytotoxicity against oat (A. sativa) and common radish (R. sativus) exhibiting moderate-to-severe toxicity for these plants. The significant selectivity towards radish (up to 3 times greater toxicity against radish) was observed in some cases. Title compounds were also tested in terms of their toxicity for freshwater crustaceans H. incongruens (ostracods) and marine luminescent bacteria A. fischeri. Although their harmful action on ostracods was not too much elevated, they were found to be highly toxic for bacteria. Various aspects of their ecotoxicity are discussed in this paper.

Novel N-Arylaminophosphonates Bearing a Pyrrole Moiety and Their Ecotoxicological Properties.

A wide range of biological activities of aminophosphonates predisposes them to find applications as anticancer, antiviral, antimicrobial, antifungal, or herbicidal agents. Despite a number of positive aspects of the use of aminophosphonates, their applications may cause a risk to the environment, which is well exemplified by the case of glyphosate. Therefore, scientists see a pressing need to rate ecotoxicity of aminophosphonates. Nowadays, it is recommended to use comprehensive tools to carry out appropriate and effective risk assessments of toxic substances. For these purposes, tests based on the acute toxicity of the luminescent bacteria Aliivibrio fischeri, as well as the measurement of sub-chronic toxicity of the crustacean Heterocypris incongruens seem to be the most convenient. A series of five diphenyl N-arylamino(pyrrole-2-yl)methylphosphonates was synthesized and preliminary evaluation of their ecotoxicological properties was performed. In order to carry out such investigations, we applied the two biotests mentioned above. Results showed that the N-(4-nitrophenyl) derivative was the most toxic for bacteria in comparison to other tested compounds. As for crustaceans, N-phenyl and N-naphthyl derivatives were found to be the most harmful, simultaneously being relatively harmless for bacteria. Such a phenomenon are discussed in correlation with the literature, while its reason is discussed with respect to the aspect of structure of the tested compounds.

Evaluation of ecotoxicological impact of new pyrrole-derived aminophosphonates using selected bioassay battery.

Six new dimethyl N-arylamino(2-pyrrolyl)methylphosphonates 2a-f were synthesized by the modified aza-Pudovik reaction. Their ecotoxicological impact using battery of bioassay was assessed using Microtox and Ostracodtoxit tests as well as phytotoxicity towards two plants, dicotyledonous radish (Raphanus sativus) and monocotyledonous oat (Avena sativa) following the OECD 208 Guideline. Ecotoxicological properties of compounds 2a-f in aspect of acute and chronic toxicity were evaluated using Heterocypris incongruens and Aliivibrio fisheri tests. The obtained results showed that tested aminophosphonates 2a-f have moderate-to-high phyto- and ecotoxicological impact. They are toxic for both plants but more toxic against dicotyledonous. The investigated compounds showed important ecotoxicity against Heterocypris incongruens crustaceans and Aliivibrio fisheri bacteria. It was found that the substituents of the phenyl ring plays a key role in the degree of toxicity. Results showed that investigated compounds are ecologically toxic and that any of their application should be implemented with care.

Synthesis, Spectral Characterization of Several Novel Pyrene-Derived Aminophosphonates and Their Ecotoxicological Evaluation Using Heterocypris incongruens and Vibrio fisheri Tests.

Four diphenyl pyrene-derived aminophosphonates were synthesized. Attempts were made to synthesize diphenyl N-(R)-α-methylbenzylamino(pyren-1-yl)methylphosphonate (3e) in order to obtain the chiral aminophosphonate bearing a pyrene moiety. Because these attempts failed, dimethyl and dibenzyl N-(R)-α-methylbenzyl substituted aminophosphonates 4 and 5 were synthesized and the predominant diastereoisomer of dimethyl aminophosphonate 4 was isolated. The resolution of the diastereomeric mixture of 5 failed. Aminophosphonates 3a-d and the predominant diastereoisomer of 4 were investigated in terms of their ecotoxicity using tests performed on the ostracode Heterocypris incongruens and the fluorescent bacterium Vibrio fisheri. The tests confirmed the moderate-to-high ecotoxicity of aminophosphonates 3a-d and 4, but no evident correlation between the structure and toxicity has been found.

The Effect of New Thiophene-Derived Aminophosphonic Derivatives on Growth of Terrestrial Plants: A Seedling Emergence and Growth Test.

The aim of this work was to synthesize selected thiophene-derived aminophosphonic systems and evaluate the phytotoxicity of newly obtained products according to the OECD 208 Guideline. Seven new thiophene-derived N-substituted dimethyl aminomethylphosphonic acid esters 2a-h were synthesized by the addition of an appropriate phosphite to azomethine bond of starting Schiff bases 1a-h, and NMR spectroscopic properties of aminophosphonates were investigated. These eight compounds were analyzed in regard to their phytotoxicity towards two plants, radish (Raphanus sativus) and oat (Avena sativa). On the basis of the obtained results, it was found that tested aminophosphonates 2a-h showed an ecotoxicological impact against selected plants, albeit to various degrees.

Utilization of starch films plasticized with urea as fertilizer for improvement of plant growth.

The utilization of starch films, obtained by extrusion of potato starch with urea as plasticizer, for the fertilization of plants has been undertaken. Release rate of urea from the starch films was conducted in water conditions. The molecular weight distribution, surface erosion and weight loss of the starch samples have been determined. The evaluation of efficiency of urea as a fertilizer in the process of release from the starch films was performed under laboratory conditions based on the plant growth test proposed by OECD 208 Guideline and the PN-ISO International Standard using oat and common radish. Although among extruded starch-based films, those that contain the highest amount of fertilizer hold the most promise for a delayed release system, the time of release of fertilizer from obtained films in undertaken study was not satisfactory. All the same, in the present study effort has been made to utilize extruded samples as a fertilizer for agriculture or horticulture purposes. Urea-plasticized starch was successfully used as a fertilizer. Plant growth assessment, including determination of such parameters as fresh and dry matter of plants and their visual evaluation, has proved the stimulating effect of using extruded films on the growth and development of cultivated plants.