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Biotransformation and kinetics

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Administrative data

Endpoint:
biotransformation and kinetics
Type of information:
experimental study
Adequacy of study:
supporting study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Experimental results from study conducted according to acceptable principles and reported in peer-reviewed journal

Data source

Reference
Reference Type:
publication
Title:
The ability of Armillariella mellea to transform cyclic monoterpenic alcohols and their acetates
Author:
Draczynska-Lusiak B, Siewinski A
Year:
1991
Bibliographic source:
J Basic Microbiol 31(5), 363-369

Materials and methods

Principles of method if other than guideline:
A biotransformation with Armillariella mellea was conducted. An amount of 0.8 to 2 g of the substance was added to well growing fungal cultures. The standard study lasted for 10 to 12 days. After the transformation phase, the mycelium was separated from nutrient solution. The solution was salted out with ammonium sulphated and extracted with ethyl ether. The extract was analysed by gas chromatography and yields of individual products were calculated.
GLP compliance:
no
Type of medium:
terrestrial

Test material

Reference
Name:
Unnamed
Type:
Constituent

Results and discussion

Transformation products:
yes
Identity of transformation productsopen allclose all
No.:
#1
Reference
Reference substance name:
Unnamed
IUPAC name:
8-hydroxymenthyl acetate
Identifier:
other: name as given in publication
Identity:
8-hydroxymenthyl acetate
No.:
#2
Reference
Reference substance name:
Unnamed
IUPAC name:
3,8-p-menthan-diol
Identifier:
other: name as given in publication
Identity:
3,8-p-menthan-diol
No.:
#3
Reference
Reference substance name:
Unnamed
Inventory number:
InventoryMultipleMappingImpl [inventoryEntryValue=EC 201-939-0]
IUPAC name:
2-isopropyl-5-methylcyclohexanol
Identity:
Cyclohexanol, 5-methyl-2-(1-methylethyl)-, (1?,2ß,5?)-
Identity:
Cyclohexanol, 5-methyl-2-(1-methylethyl)-, (1R,2S,5R)-rel-
Identifier:
CAS number
Identity:
15356-70-4
Identifier:
other: EINECS name
Identity:
Menthol
CAS number:
89-78-1
Molecular formula:
C10H20O
Molecular weight:
156.265
SMILES notation:
OC(C(CCC1C)C(C)C)C1
InChl:
InChI=1/C10H20O/c1-7(2)9-5-4-8(3)6-10(9)11/h7-11H,4-6H2,1-3H3

Any other information on results incl. tables

Racemic menthyl acetate underwent biotransformation: the main compounds were 8-hydroxymenthyl acetate and 3,8-p-menthandiol. These were formed as the main components in proportions 28 and 24% with respect to the total of isolated products. No menthyl acetate was isolated at the end of the transformation study.

A second experiment was conducted, in which two subsequent transformation studies were conducted with the very same fungal culture. A. mellea transformed menthyl acetate by simultaneous (not subsequent, as before) hydrolysis of ester bond and hydroxylation of unreacted ester in this second study and the resulting main compounds were menthol and 3,8-p-menthandiol.

Applicant's summary and conclusion

Conclusions:
In a study with fungal cultures of A. mellea the substance menthyl acetate was biotransformed to a significant extent.
Executive summary:

A biotransformation with Armillariella mellea was conducted. An amount of 0.8 to 2 g of the substance was added to well growing fungal cultures. The standard study lasted for 10 to 12 days. After the transformation phase, the mycelium was separated from nutrient solution. The solution was salted out with ammonium sulphated and extracted with ethyl ether. The extract was analysed by gas chromatography and yields of individual products were calculated. Racemic menthyl acetate underwent biotransformation: the main compounds were 8-hydroxymenthyl acetate and 3,8-p-menthandiol. These were formed as the main components in proportions 28 and 24% with respect to the total of isolated products. No menthyl acetate was isolated at the end of the transformation study.

A second experiment was conducted, in which two subsequent transformation studies were conducted with the very same fungal culture. A. mellea transformed menthyl acetate by simultaneous (not subsequent, as before) hydrolysis of ester bond and hydroxylation of unreacted ester in this second study and the resulting main compounds were menthol and 3,8-p-menthandiol. No explanation for the different outcome of the two studies was provided.