Methyl isonicotinate

Toxicity to microorganisms

Link to relevant study record(s)

Reference

Endpoint:

toxicity to microorganisms, other

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Data is from peer reviewed journal

Justification for type of information:

Data is from peer reviewed journal

Qualifier:

according to guideline

Guideline:

other: as mentioned below

Principles of method if other than guideline:

96 h toxicity test of substance methyl isonicotinate was conducted in Ciliate Tetrahymena pyriformis.

GLP compliance:

not specified

Specific details on test material used for the study:

- Name of test material (IUPAC name): Methyl Isonicotinate
- Molecular formula: C7H7NO2
- Molecular weight: 137.1373 g/mol
- Smiles notation: c1(C(=O)OC)ccncc1
- InChl: 1S/C7H7NO2/c1-10-7(9)6-2-4-8-5-3-6/h2-5H,1H3
- Substance type: Organic
- Physical state: Liquid
- Analytical purity: >95 %
- Other: The test chemicals were purchased from Aldrich Chemical Company, Wilwaukee, Wisconsin, or Pfaltz and Bauer Inc., Stamford, Connecticut, and not repurified.

Analytical monitoring:

not specified

Details on sampling:

- Concentrations: Test chemical conc. used for the study was 0.5 mg/l.

Vehicle:

not specified

Details on test solutions:

Methyl Isonicotinate was diluted to 500 g/l with sterile distilled water.

Test organisms (species):

Tetrahymena pyriformis

Test type:

static

Water media type:

freshwater

Total exposure duration:

60 h

Test temperature:

28°C

Details on test conditions:

TEST SYSTEM
- Test vessel: Erlenmeyer flasks
- No. of vessels per concentration (replicates): Each test chemical was assayed in duplicate for a minimum of three replicates using a five-step graded concentration series.

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : Population growth and density were determined spectrophotometrically as absorbance at 540 mm.

Reference substance (positive control):

not specified

Key result

Duration:

60 h

Dose descriptor:

EC50

Effect conc.:

893.32 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: Population

Remarks on result:

other: 95% C. I. = 701.10 - 2161.48 mg/l

Reported statistics and error estimates:

Population growth determinations were done using probit analysis in the Statistical Analysis System (SAS) software. For these data Y equals percentage control absorbance and X equals concentration (mg/liter). The 60-hr IGCso (50% growth inhibition concentration) and 95% confidence interval were determined and transformed to millimoles per liter for comparison. The goodness of fit was determined using the x2 value.

Table:POPULATION GROWTH INHIBITIONTO Tetrahymena of SELECTED FOUR-POSITION PYRIDINES.

 

Derivative	CAS no.	Probit regression equation	P > x2	n	60 h IGC50 (mg/l)
OCOCH3	2459-09-8	Y = 9.2858 - 0.0048X	0.9847	23	893.32 mg/l (701.10 - 2161.48 mg/l)

Validity criteria fulfilled:

not specified

Conclusions:

The 60 hr EC50 value of test chemical methyl isonicotinate was determined to be 893.32 mg/l in Ciliate Tetrahymena pyriformis.

Executive summary:

96 h toxicity test of substance methyl isonicotinate was conducted in Ciliate Tetrahymena pyriformis. Methyl Isonicotinate was diluted to 500 g/l with sterile distilled water. The study was performed in freshwater under static conditions at a temperature of 28°C.The amicronucleated strain GL-C of the common freshwater ciliate Tetrahymena pyriformis was reared in axenic culture at 28°C in a semidefined medium. Cultures were grown for 60 hr in 250-ml Erlenmeyer flasks containing 50 ml of test solution. Population growth and density were determined spectrophotometrically as absorbance at 540 mm. Each 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.Population growth determinations were done using probit analysis in the Statistical Analysis System (SAS) software. For these data Y equals percentage control absorbance and X equals concentration (mg/liter). The 60-hr IGCso (50% growth inhibition concentration) and 95% confidence interval were determined and transformed to millimoles per liter for comparison. The goodness of fit was determined using the x2 value.The 60 hr EC50 value of test chemical methyl isonicotinate was determined to be 893.32 mg/l in Ciliate Tetrahymena pyriformis.

Description of key information

96 h toxicity test of substance methyl isonicotinate was conducted in Ciliate Tetrahymena pyriformis (T. WAYNE SCHULTZ et. al; 1985). Methyl Isonicotinate was diluted to 500 g/l with sterile distilled water . The study was performed in freshwater under static conditions at a temperature of 28°C.The amicronucleated strain GL-C of the common freshwater ciliate Tetrahymena pyriformis was reared in axenic culture at 28°C in a semidefined medium. Cultures were grown for 60 hr in 250-ml Erlenmeyer flasks containing 50 ml of test solution. Population growth and density were determined spectrophotometrically as absorbance at 540 mm. Each 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.Population growth determinations were done using probit analysis in the Statistical Analysis System (SAS) software. For these data Y equals percentage control absorbance and X equals concentration (mg/liter). The 60-hr IGCso (50% growth inhibition concentration) and 95% confidence interval were determined and transformed to millimoles per liter for comparison. The goodness of fit was determined using the x2 value.The 60 hr EC50 value of test chemical methyl isonicotinate was determined to be 893.32 mg/l in Ciliate Tetrahymena pyriformis.

Key value for chemical safety assessment

EC50 for microorganisms:

893.32 mg/L

Additional information

Various experimental studies for the target chemical Methyl Isonicotinate (CAS No. 2459-09-8)were reviewed for toxicity to micro-organism endpoint which are summarized as below:

 

In an experimental key study from peer reviewed journal (T. WAYNE SCHULTZ et. al; 1985), 96 h toxicity test of substance methyl isonicotinate was conducted in Ciliate Tetrahymena pyriformis. Methyl Isonicotinate was diluted to 500 g/l with sterile distilled water. The study was performed in freshwater under static conditions at a temperature of 28°C.The amicronucleated strain GL-C of the common freshwater ciliate Tetrahymena pyriformis was reared in axenic culture at 28°C in a semidefined medium. Cultures were grown for 60 hr in 250-ml Erlenmeyer flasks containing 50 ml of test solution. Population growth and density were determined spectrophotometrically as absorbance at 540 mm. Each 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.Population growth determinations were done using probit analysis in the Statistical Analysis System (SAS) software. For these data Y equals percentage control absorbance and X equals concentration (mg/liter). The 60-hr IGCso (50% growth inhibition concentration) and 95% confidence interval were determined and transformed to millimoles per liter for comparison. The goodness of fit was determined using the x2 value. The 60 hr EC50 value of test chemical methyl isonicotinate was determined to be 893.32 mg/l in Ciliate Tetrahymena pyriformis.

 

Another aquatic toxicity study of micro-organism to the test substance Methyl Isonicotinate (CAS no. 2459-09-8) was conducted using Photobacterium phosphoreum, strain NRRL-B-11177 (also referred to as Vibrio fischerii, strain NRRL-B-11177) (Klaus L.E. Kaiser and Virginia S. Palabrica, 1991). The study was performed at a temperature of 15ᵒC and pH range 5 to 9, respectively. Recommneded reference substance that can be used for the study were Phenol and Sodium pentachlorophenate, respectively. When the test bacterium Photobacterium phosphoreum, strain NRRL-B-11177 was exposed to the test chemical Methyl Isonicotinate, reduction in light output was observed. Thus, based on this effect, the EC50 value during 5, 15 and 30 min exposure period was determined to be 198.235, 207.588 and 217.3669 mg/l, respectively.

 

Thus, based on the overall reported results for target chemical Methyl Isonicotinate, EC50 value ranges from198.235 to 893.32 mg/l, respectively.