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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 OSTRACODTOXKIT TM 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 (EC 50 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., Competing Interests: The authors declare no conflict of interest. The funders had no role in the design of the study, in the collection, analyses, or interpretation of data, in the writing of the manuscript, or in the decision to publish the results.

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., Competing Interests: The authors declare no conflict of interest. The founding sponsors had no role in the design of the study; in the collection, analyses, or interpretation of data; in the writing of the manuscript, and in the decision to publish the results.

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.