4'-methylacetophenone

Additional information on environmental fate and behaviour

Administrative data

Endpoint:

additional information on environmental fate and behaviour

Type of information:

experimental study

Adequacy of study:

supporting study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Publication which meets generally accepted scientific standards

Data source

Reference

Reference Type:

publication

Title:

Biotransformation of aliphatic and aromatic ketones, including several monoterpenoid ketones and their derivatives by five species of marine microalgae

Author:

Hook IL, Ryan S, Sheridan H

Year:

2003

Bibliographic source:

Phytochemistry 63(1), 31-36

Materials and methods

Test guideline

Qualifier:

no guideline followed

Principles of method if other than guideline:

Three saltwater green alga (Chlorella minutissima, Nannochlorus atomus, Dunaliella parva) und two red alga (Porphyridium pupureum, Isochrysis galbana) were allowed to grow for 7 days. Then the test substance was added to a final concentration of 100 mg/L and incubated under sterile conditions. The parent compound decrease and the amount of transformation product was followed analytically.

GLP compliance:

no

Type of study / information:

Biotransformation in marine green and red alga

Test material

Test material information

Constituent 1

Reference substance name:

4'-methylacetophenone

EC Number:

204-514-8

EC Name:

4'-methylacetophenone

Cas Number:

122-00-9

Molecular formula:

C9H10O

IUPAC Name:

1-(4-methylphenyl)ethanone

Details on test material:

- Name of test material (as cited in study report): 4-methyl-acetophenone or 4-CH-acetophenone or (22)
- Supplier: Aldrich Co.

Results and discussion

Any other information on results incl. tables

4'-methylacetophenone was most effectively reduced by one of the red alga species (P. purpureum). Examination of the products of reduction showed that some stereoselectivity in the reduction by one of the green algae (D. parva) with excess of the S-(-)-isomer being shown.

Table: Biotransformation percentrages after 5 days

C. minutissima	N. atomus	D. parva	P. purpureum	I. galbana
60 %	66 %	35 %	75 %	4 %

Applicant's summary and conclusion

Conclusions:

In conclusion the transformation of 4'methylacetophenone in five marine algae species (3 green algae and 2 red algae) to p,alpha-Dimethylbenzyl alcohol was evidenced at rates from 4 to 75 % in 5 days with some stereoselectivity in one species.

Executive summary:

The biotransformation of 4'-methylacetophenone by three species of marine green algae (Chlorella minutissima, Nannochlorus atomus, Dunaliella parva) and two marine red alga (Porphyridium pupureum, Isochrysis galbana) was investigated. The publication reports an acceptable level of detail and is rated Klimisch 2 (reliable with restrictions).

Algal broth was obtained by culturing the algae in artificial sea water at 25 °C under illumination by cool white fluorescent light (20 W/m², 6 hours darkness / 18 hours light). The algal broth was then diluted and the test substance diluted in methanol (10 %) was added at a concentration of 100 mg/L or solvent control or control.

Dilutions of microalgae (1:5) were made in conical flasks (250 mL) to provide a 40 % flask fill (i.e. 20 mL algal broth into 80 mL artificial sea water. Algae were allowed to grow statically for 7 days at which stage a solution of substrate in methanol (1 mL) was added. Aliquots (10 mL) were taken from the culture flasks in triplicate at intervals of 24, 48, 72, 96 and 120 hours. These were extracted with equal volumes of distilled diethyl ether. The ether layer was separated, dried over Na2SO4, filtered and evaporated to dryness in vacuum. The residue was re-dissolved in diethyl ether (1 mL) and analyzed under standard GC conditions. The three replicates for a given data point of the time course experiment for each alga were combined. The algal cells were removed by filtration and the aqueous medium was extracted with diethyl ether. The components of the diethyl ether extracts were separated by column chromatography on silica gel. Products were visualized by UV light or by spraying with vanillin in concentrated H2SO4 (l %) or freshly prepared iodoplatinate spray. Compounds were characterized by spectroscopic analysis and by comparison with authentic samples or literature values.

4'-methylacetophenone was most effectively reduced by one of the red alga species (P. purpureum). Examination of the products of reduction showed that some stereoselectivity in the reduction to p,alpha-Dimethylbenzyl alcohol by one of the green algae (D. parva) with excess of the S-(-)-isomer being shown. The biotransformation rates were 60, 66 and 35 % in the green algal species (Chlorella minutissima, Nannochlorus atomus, Dunaliella parva), respectively and 75 and 4 % in the red algal species (Porphyridium pupureum, Isochrysis galbana), respectively.

In conclusion the transformation of 4'methylacetophenone in five marine algae species (3 green algae and 2 red algae) to p,alpha-Dimethylbenzyl alcohol was evidenced at rates from 4 to 75 % in 5 days with some stereoselectivity in one species.