Ecotoxicity studies of the levulinate ester series

Abstract

Abstract:The increasing interest in the development of novel green solvents has led to the synthesis of benign alternative products with minimized environmental impacts.However, most of published studies on green solvents focus primarily on their physicochemical properties, with limited emphasis on absence of ecotoxicological assessment. In this study, we evaluated the acute ecotoxicity of four levulinates (levulinic acid, methyl levulinate, ethyl levulinate and butyl levulinate) on freshwater algae (Chlamydomonas reinhardtii), bacteria (Vibrio fischeri), daphnids (Daphnia magna) and earthworms (Eisenia foetida) using various dose-response tests. As a general trend, the toxicity of levulinate esters in aquatic exposure (assessed as the EC 50 ) increased as a function of increasing alkyl chain length; accordingly, the most toxic compound for the aquatic organisms was butyl levulinate, followed by ethyl levulinate and methyl levulinate. The most toxic compound for Eisenia foetida (terrestrial exposure) was methyl levulinate, followed by ethyl levulinate, butyl levulinate and levulinic acid; in this case, we observed an inverse relationship between toxicity and alkyl chain length. Based on both the lowest EC 50 found in the aquatic media and the ratio between predicted environmental concentration (PEC) and the predicted no-effect concentration (PNEC), we have estimated the maximum allowable values in the 2 environment for these chemicals to be 1.093 mg L -1 for levulinic acid, 2.761 mg L -1 for methyl levulinate, 0.982 mg L -1 for ethyl levulinate and 0.151 mg L -1 for butyl levulinate.

Humins in the environment: early stage insights on ecotoxicological aspects

“…Among all the tested compounds, the median effective concentrations highlighted the lack of toxicity of ML in both Daphnia magna and Pseudokirchneriella subcapitata tests (EC50> 500 mg L −1 ). These results are consistent with the daphnia test results obtained by Lomba et al ., where the EC50 24h was 2761 ± 512 mg L −1 . Irrespective of the duration of exposure, these values confirm that ML is a chemical causing no short‐term toxicity effects.…”

Acute embryo toxicity and teratogenicity of three potential biofuels also used as flavor or solvent

“…1). The LC 50 -value determined for EL was even lower than EC 50 -values reported for other organisms by Lomba et al (2014), e.g., Chlamydomonas reinhardtii (green alga; 6889 mg/L), Vibrio fischeri (bacterium; 182 mg/L), Daphnia magna (water flea; 982 mg/L) or Eisenia foetida (earthworm, 848 mg/L). Thus, zebrafish embryos appear to be among the most sensitive organisms for EL.…”

“…This is especially true for biofuels but even for EL, that is used in the food industry, only one study on its (eco)toxicological effects was found in the available literature (Lomba et al, 2014) while some toxicological data is available (e.g. acute oral and dermal toxicity, as well as information regarding skin irritation; Fragrance raw material monographs; Anonymous, 1982).…”

Exploring the usefulness of key green physicochemical properties: Quantitative structure–activity relationship for solvents from biomass

“…Regarding ecotoxicity information, levulinate esters were studied in 3 aquatic species: V. fischeri, Chlamydomonas reinhardtii, and D. magna by Lomba et al [12]. Acute effective concentrations of the levulinate esters recompiled for V. fischeri and D. magna are shown in Table 2, whereas EC50 values for algae are shown in Table 3.…”