3'-nitroacetophenone

Endpoint summary

Description of key information

Short-term toxicity to fish:

The short-term toxicity of the substance 3'-nitroacetophenoneto fish is predicted using QSAR toolbox version. 3.4, based on the effects observed in a semi-static freshwater system during a 96 hr exposure. The lethal concentration (LC50) for the substance3'-nitroacetophenoneis estimated to be 579.00 mg/L. Based on this value, it can be concluded that the test chemical3'-nitroacetophenonecan be considered as non-toxic to fish at predicted lethal concentration and can be considered not-classified as per the CLP classification criteria.

Short term toxicity to aquatic invertebrates:

Short term toxicity to aquatic invertebrates was performed in Daphnia magna for 48 hrs according to OECD Guideline 202. The stock solution (100.0 mg/L) was prepared  by dissolving  light brown powder in reconstituted  water. The test substance was tested at the concentrations 0, 4, 8, 16, 32 and 64 mg/L.

25 ml per replicate in 50 ml glass vessel were used. 5 daphnids were used in each testing vessels. The experiment was performed in darkness without feeding of daphnia. Effects on immobilization were observed for 48 hours.

The median effective concentration (EC50) for the test substance, 3'-nitroacetophenone in Daphnia magna was determined to be 35.6 mg/L for immobilization effects.

This value indicates that the substance is likely to be hazardous to aquatic invertebrates and can be classified as aquatic chronic 3 as per the CLP criteria.

Toxicity to aquatic algae

Freshwater algal growth inhibition test was carried out on Desmodesmus subspicatus with the substance 3-Nitroacetophenone to OECD Guideline 201.

The stock solution (100 mg/L) was prepared by dissolving light brown powder in OECD growth medium. The solution was kept in ultrasonic bath for 20 mins. Test solutions  of required concentrations  were prepared by mixing the stock solution of the test sample with OECD growth medium and inoculum culture. Conc. of test chemical used for the study was 0, 2.5, 5, 10, 20, 40 and 80 mg/L, respectively. The test was performed under static conditions in a static fresh water system at a temp. of 23±2°C. Initial cell density of test organism used was 5x10(3) cells/ml. Determination of cell counting involve the use of microscope with counting chamber Cyrus I or electronic particle counter.. ErC50 was calculated using non-linear regression by the software Prism 4.0.

The median effective concentration (EC50) for the test substance 3-Nitroacetophenone in Desmodesmus subspicatus was determined to be 16.9 mg/L on the basis of effects on growth rate in a 72 hour study.Thus, based on this value, test chemical 3-Nitroacetophenone can be considered as toxic to aquatic organisms and thus can be classified as aquatic chronic category 3 as per the CLP criteria.

Toxicity to microorganisms

Antibacterial activity of 20 acetophenone derivatives was evaluated against two Gram-positive and three Gram-negative organisms, namely, Bacillus subtilis NCIM 2718, Staphylococcus aureus NCIM5021, Salmonella typhi NCIM2501, Enterobacter aerogenes NCIM5139, and Proteus vulgaris NCIM2813 by two-fold dilution method.

 

BATH test is usually performed to determine the hydrophobicity of the bacteria. Bacterial cells have an affinity to hydrocarbons such as hexadecane. The more hydrophobic the bacterial cell, the greater is its affinity to the hydrocarbon, resulting in a transfer of cells from the aqueous suspension to the organic phase, leading to a reduction in the turbidity of the culture in the former. The optical density solution is measured at hexadecane concentrations ranging from 0.0 to 0.2 ml. If the OD (measured at 400 nm) decreases with increasing hexadecane amounts it indicates that the micro-organism is hydrophobic and if a reverse trend is observed then the microorganism is hydrophilic. Decreasing OD indicates that more of the cells are moving to the hydrophobic hexadecane. Bacteria were cultured in tryptic soy broth medium until the growth reached mid-logarithmic phase. This broth was centrifuged and washed twice with phosphate–urea–magnesium (PUM) buffer containing 17 g K₂HPO₄, 7.26 g KH₂PO₄, 1.8 g urea and 0.2 g MgSO₄.7H₂O per litre. The washed cells were re-suspended in PUM buffer to reach an OD of 1.0 at 400 nm (OD400). Aliquots of 1.0 ml of this suspension were transferred to a set of test tubes, to which increasing volumes (ranging from 0–0.2 ml in steps of 0.05 ml) of hexadecane were added. The test tubes were shaken for 10 min and allowed to stand for 2 min to facilitate the phase separation. The OD of the aqueous suspension was measured at 400 nm, while cell-free buffer served as the blank.

 

The Minimum Inhibitory Concentration (MIC) of Bacillus subtilis NCIM 2718 in terms of -log(µM) when exposed to 3 nitroacetophenone is 0.723

Additional information

Short-term toxicity to fish:

Three studies including two predicted result from validated predictions and one experimental data for endpoint short term fish toxicity to target chemical 3'-nitroacetophenone (Cas no. 121-89-1) with relevant read across substance which is close to target using log kow as primary descriptor were summarized as followes:

First data for target chemical is predicted using OECD QSAR toolbox version. 3.4 (2017), to indicate the short-term toxicity of the substance 3'-nitroacetophenone. The rediction is based on the effects observed in a semi-static freshwater system during a 96 hr exposure. The lethal concentration (LC50) for the substance 3'-nitroacetophenone is estimated to be 579.00 mg/L. Based on this value, it can be concluded that the test chemical 3'-nitroacetophenone can be considered as non-toxic to fish at environmentally relevant concentrations and can be considered not-classified as per the CLP classification criteria.

Another prediction model EPI Suite ECOSAR version 1.10, estimated the 96 hours LC50 to be 388.456 mg/l on Fish for substance 3'-nitroacetophenone (CAS no. 121-89-1) on the basis of mortality effects. Thus, based on this value, it can be concluded that the test chemical 3'-nitroacetophenone can be considered as non-toxic to fish and thus cannot be classified as hazardous as per the CLP criteria.

Above both predicted results are further supported by experimental result of read across substance Cyclohexanol (Cas no. 108-93-0). A short term fish toxicity study on test species Pimephales promelas(Fathead Minnow) of chemical Cyclohexanol (Cas no.108-93-0)was conducted for exposure period of 96 hrs. In the experiment, static conditions were maintained with test temp. 24.4 Deg.C , 47.0 mg/L CaCO3 hardness, 7.3 pH, 6.5 mg/L Dissolve oxygen , ALKALINITY: 40.2 mg/L CaCO3 at nominal concentration 0,133,222,369,616 and 1026 mg/l. On the basis of mortality effect, the lethal concentration (LC50) on fish Pimephales promelas (Fathead Minnow) was observed to be 704 mg/l. Thus considering the lethal concentration the test substance Cyclohexanol (Cas no.108-93-0) can be considered as non toxic to fish and thus not consider for further classification for fish as per the CLP criteria.

Thus based on the above all predicted and experimental result of the target and read across substance Cyclohexanol (Cas no. 108-93-0) indicates that 3'-nitroacetophenone (Cas no. 121-89-1) is likely to be non toxic to fish and thus not consider for the aquatic classification as per the CLP criteria.

Short term toxicity to aquatic invertebrates:

The study from Abitec laboratory (Determination of the inhibition of the mobility of daphnids, 2016) which has K1 reliability were used as key for short term toxicity to aquatic invertebrates.

The test was performed in Daphnia magna for 48 hrs according to OECD Guideline 202. The stock solution (100.0 mg/L) was prepared  by dissolving  light brown powder in reconstituted  water. The test substance was tested at the concentrations 0, 4, 8, 16, 32 and 64 mg/L.

25 ml per replicate in 50 ml glass vessel were used. 5 daphnids were used in each testing vessels. The experiment was performed in darkness without feeding of daphnia. Effects on immobilization were observed for 48 hours.

The median effective concentration (EC50) for the test substance, 3'-nitroacetophenone in Daphnia magna was determined to be 35.6 mg/L for immobilization effects.

This value indicates that the substance is likely to be hazardous to aquatic invertebrates and can be classified as aquatic chronic 3 as per the CLP criteria.

Toxicity to aquatic algae

Freshwater algal growth inhibition test was carried out on Desmodesmus subspicatus with the substance 3-Nitroacetophenone to OECD Guideline 201.

The stock solution (100 mg/L) was prepared by dissolving light brown powder in OECD growth medium. The solution was kept in ultrasonic bath for 20 mins. Test solutions  of required concentrations  were prepared by mixing the stock solution of the test sample with OECD growth medium and inoculum culture. Conc. of test chemical used for the study was 0, 2.5, 5, 10, 20, 40 and 80 mg/L, respectively. The test was performed under static conditions in a static fresh water system at a temp. of 23±2°C. Initial cell density of test organism used was 5x10(3) cells/ml. Determination of cell counting involve the use of microscope with counting chamber Cyrus I or electronic particle counter.. ErC50 was calculated using non-linear regression by the software Prism 4.0.

The median effective concentration (EC50) for the test substance 3-Nitroacetophenone in Desmodesmus subspicatus was determined to be 16.9 mg/L on the basis of effects on growth rate in a 72 hour study.Thus, based on this value, test chemical 3-Nitroacetophenone can be considered as toxic to aquatic organisms and thus can be classified as aquatic chronic category 3 as per the CLP criteria.

Toxicity to microorganisms

Three studies including two experimental data and one predicted result from validated prediction for endpoint toxicity to micro organisms to target chemical 3'-nitroacetophenone(Cas no. 121-89-1) with relevant read across substance which is close to target using log kow as primary descriptor were summarized as followed:

First study of target available from experimental data source (Chem Biol Drug Des 2008; 72: 303–313; 2008) which indicate the antibacterial activity of 20 acetophenone derivatives was evaluated against two Gram-positive and three Gram-negative organisms, namely, Bacillus subtilis NCIM 2718, Staphylococcus aureus NCIM5021, Salmonella typhi NCIM2501, Enterobacter aerogenes NCIM5139, and Proteus vulgaris NCIM2813 by two-fold dilution method.BATH test is usually performed to determine the hydrophobicity of the bacteria. Bacterial cells have an affinity to hydrocarbons such as hexadecane. The more hydrophobic the bacterial cell, the greater is its affinity to the hydrocarbon, resulting in a transfer of cells from the aqueous suspension to the organic phase, leading to a reduction in the turbidity of the culture in the former. The optical density solution is measured at hexadecane concentrations ranging from 0.0 to 0.2 ml. If the OD (measured at 400 nm) decreases with increasing hexadecane amounts it indicates that the micro-organism is hydrophobic and if a reverse trend is observed then the microorganism is hydrophilic. Decreasing OD indicates that more of the cells are moving to the hydrophobic hexadecane. Bacteria were cultured in tryptic soy broth medium until the growth reached mid-logarithmic phase. This broth was centrifuged and washed twice with phosphate–urea–magnesium (PUM) buffer containing 17 g K2HPO4, 7.26 g KH2PO4, 1.8 g urea and 0.2 g MgSO4.7H2O per litre. The washed cells were re-suspended in PUM buffer to reach an OD of 1.0 at 400 nm (OD400). Aliquots of 1.0 ml of this suspension were transferred to a set of test tubes, to which increasing volumes (ranging from 0–0.2 ml in steps of 0.05 ml) of hexadecane were added. The test tubes were shaken for 10 min and allowed to stand for 2 min to facilitate the phase separation. The OD of the aqueous suspension was measured at 400 nm, while cell-free buffer served as the blank.The Minimum Inhibitory Concentration (MIC) of Bacillus subtilis NCIM 2718 in terms of -log(µM) when exposed to 3 nitroacetophenone is 0.723 which is equivalent to 3990 mg/l.

And the toxicity to micro organism of the substance 3'-nitroacetophenoneto micro organism is predicted using QSAR toolbox version.3.4, based on the effects observed in a static freshwater system during a 48 hr exposure. The Inhibition growth concentration (IGC50) for the substance3'-nitroacetophenoneis estimated to be 236.51 mg/L. Based on this value, it can be concluded that the test chemical 3'-nitroacetophenonemay have no concern to micro organism toxicity for acute exposure.

Whereas read across chemical 4-Benzoylpyridine (CAS no.14548-46-0) from experimental result indicate twenty-two four-position derivatives of pyridine (CS5H5N) including chemical 4-Benzoylpyridine (Cas no. 14548-46-0) were tested following an acute static regime with biological response being monitored as population growth of Tetrahymena pyriformis. Stock solution was prepared in 50 g/liter vehicle DMSO. The amicronucleated strain GL-C of the common freshwater ciliate Tetrahymena pyriformis was reared in axenic culture at 28°C in a semi defined medium (Schultz et al., 1980). Test chemical was assayed in duplicate for a minimum of three replicates using a five-step graded concentration series. Each replicate was assayed with freshly prepared stock solutions and flasks without test chemicals were used as controls. And Population growth determinations were done using probit analysis in the Statistical Analysis System (SAS) software which suggest that effect concentration (EC50) for the substance 4-Benzoylpyridine (CAS no.14548-46-0) was determine to be 227.02 mg/l on micro organism Tetrahymena pyriformis on the basis of population effect in static fresh water for 60 hrs.exposure period with 95 % confidence limit of 164.13 - 566.45.

Thus all available information for micro organism toxicity interpreted the common conclusion that the target chemical 3'-nitroacetophenone (Cas no. 121-89-1) may not have concern for toxicity to micro organism for acute exposure period.