Propiophenone

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:

weight of evidence

Reliability:

4 (not assignable)

Rationale for reliability incl. deficiencies:

documentation insufficient for assessment

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 I.L., Ryan S. and Sheridan. H.

Year:

2003

Bibliographic source:

Phytochemistry 63 (2003) 31–36

Materials and methods

Principles of method if other than guideline:

The biotransformation of a series of aromatic ketones related to acetophenone by five cultures of photosynthetic microalgae is reported.

GLP compliance:

no

Type of study / information:

The biotransformation of a series of aromatic ketones related to acetophenone by five cultures of photosynthetic microalgae is reported.

Test material

Test material information

Constituent 1

Reference substance name:

1-phenylethanone

IUPAC Name:

1-phenylethanone

Results and discussion

Any other information on results incl. tables

Acetophenone was reduced to the corresponding alcohol by all of the test cultures within the five day period with P. purpureum and N. atomus being the most effective and D. parva being the least effective. In the case of P. purpureum the biotransformation was 90 % completed after 2 days. N. atomus, C. minutissima and I. galbana had undergone 50 % reduction of substrate after 4 days. For D. parva a maximum reduction of only 21 % was obtained after 5 days however, this organism exhibited the greatest stereoselectivity in the reduction of the substrate with an enantiomeric excess of 29.5 % of the the S-(-)-isomer being produced. C. minutissima also demonstrated stereoselectivity in the reduction of this substrate but with maximum excess of 14.8 % of the S-(-)- isomer being produced. The enantiomeric excess of the product produced by the other algal species was < 1 %.

The 4-chloro and 4- methyl derivatives of acetophenone were also reduced to the corresponding alcohols with 4-Cl-Acetophenone being reduced most effectively by I. galbana. 4-Methyl acetophenone was most effectively reduced by P. purpureum. Examination of the products of reduction of this series of compounds showed that some stereoselectivity was demonstrated in the reduction of 4-Cl-Acetophenone and 4-CH₃-Acetophenone by D. parva with excess of the S-(-)-isomer being shown.

It is interesting to note that neither 4- hydroxy acetophenone or benzophenone were reduced by any of these cultures. A study of the biotransformation of similar substrates by Euglena has also shown stereoselective reduction of many aromatic keto substrates with an excess of the S-()-isomer being produced. In most cases there was no reduction of hydroxyacetophenones, however benzophenone was biotransformed to benzhydrol (87 %) within 4 days (Shimoda et al., 1998).

Biotransformation (%) of the substance by test microalgae and the enantiomeric excess (e.e) of products formed after a 5 day incubation period

Organism (%) compound biotransformed	C. minutissima	N. atomus	D. parva	P. purpureum	I. galbana
Acetophenone	65 (14.88 e.e)	90	21 (29.52 e.e)	97	64
4-Cl-Acetophenone	36	28	21	53	99
4-CH3-Acetophenone	60	66	35	75	4
4-OH-Acetophenone	0	0	0	0	0
Benzophenone	0	0	0	0	0

Applicant's summary and conclusion

Conclusions:

The substance is reduced to the corresponding alcohols by 5 different microalgae in a different degree in a 5 day incubation period.

Executive summary:

The biotransformation of the aliphatic ketones was assessed; the reduction of acetophenone and of a series of aromatic ketones related to acetophenone was investigated.

Acetophenone was reduced to the corresponding alcohol by all of the test cultures within the five day period with P. purpureum and N. atomus being the most effective and D. parva being the least effective. In the case of P. purpureumthe biotransformation was 90 % completed after 2 days. N. atomus, C. minutissima and I. galbana had undergone 50 % reduction of substrate after 4 days. For D. parvaa maximum reduction of only 21 % was obtained after 5 days however, this organism exhibited the greatest stereoselectivity in the reduction of the substrate with an enantiomeric excess of 29.5 % of the the S-(-)-isomer being produced. C. minutissima also demonstrated stereoselectivity in the reduction of this substrate but with maximum excess of 14.8 % of the S-(-)- isomer being produced. The enantiomeric excess of the product produced by the other algal species was < 1 %.

Reduction of the acetophenone derivatives has also been observed.

Conclusion

The substance is reduced to the corresponding alcohols by 5 different microalgae in a 5 day incubation period.