Open AccessSpiroethers of German chamomile inhibit production of aflatoxin G 1 and trichothecene mycotoxin by inhibiting cytochrome P450 monooxygenases involved in their biosynthesis
Author(s) -
Yoshinari Tomoya,
Yaguchi Atsushi,
TakahashiAndo Naoko,
Kimura Makoto,
Takahashi Haruo,
Nakajima Takashi,
SugitaKonishi Yoshiko,
Nagasawa Hiromichi,
Sakuda Shohei
Publication year - 2008
Publication title -
fems microbiology letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.899
H-Index - 151
eISSN - 1574-6968
pISSN - 0378-1097
DOI - 10.1111/j.1574-6968.2008.01195.x
Subject(s) - trichothecene , monooxygenase , mycotoxin , aflatoxin , cytochrome p450 , biosynthesis , cytochrome , chemistry , biology , biochemistry , food science , gene , enzyme
The essential oil of German chamomile showed specific inhibition toward aflatoxin G 1 (AFG 1 ) production, and ( E )‐ and ( Z )‐spiroethers were isolated as the active compounds from the oil. The ( E )‐ and ( Z )‐spiroethers inhibited AFG 1 production of Aspergillus parasiticus with inhibitory concentration 50% (IC 50 ) values of 2.8 and 20.8 μM, respectively, without inhibiting fungal growth. Results of an O‐ methylsterigmatocystin (OMST) conversion study indicated that the spiroethers specifically inhibited the OMST to AFG 1 pathway. A cytochrome P450 monooxygenase, CYPA, is known as an essential enzyme for this pathway. Because CYPA has homology with TRI4, a key enzyme catalyzing early steps in the biosynthesis of trichothecenes, the inhibitory actions of the two spiroethers against TRI4 reactions and 3‐acetyldeoxynivalenol (3‐ADON) production were tested. ( E ) ‐ and ( Z ) ‐ spiroethers inhibited the enzymatic activity of TRI4 dose‐dependently and interfered with 3‐ADON production by Fusarium graminearum , with IC 50 values of 27.1 and 103 μM, respectively. Our results suggest that the spiroethers inhibited AFG 1 and 3‐ADON production by inhibiting CYPA and TRI4, respectively.