Cerniglia C E, Althaus J R, Evans F E, Freeman J P, Mitchum R K, Yang S K
Chem Biol Interact. 1983 Apr-May;44(1-2):119-32. doi: 10.1016/0009-2797(83)90134-5.
The mechanism of naphthalene oxidation by the filamentous fungus, Cunninghamella elegans is described. C. elegans oxidized naphthalene predominately to trans-1,2-dihydroxy-1,2-dihydroxy-1,2-dihydronaphthalene. A trans configuration was assigned for the dihydrodiol by nuclear magnetic resonance (NMR) spectroscopy at 500 MHz which showed a large coupling constant (J1,2) of 11.0 Hz. Comparison of the circular dichroism spectrum of the fungal trans-1,2-dihydroxy-1,2-dihydronaphthalene to that formed by mammalian enzyme systems indicated that the fungal dihydrodiol contained 76% (+)-(1S,2S)-dihydrodiol as the predominant enantiomer. Other naphthalene metabolites formed by C. elegans were identified as 1-naphthol, 2-naphthol and 4-hydroxy-1-tetralone. Incubation of C. elegans with naphthalene and 18O2 indicated that the trans-1,2-dihydroxy-1,2-dihydronaphthalene contained one atom of molecular oxygen which indicated a monooxygenase catalyzed reaction while similar incubations with naphthalene and H182O indicated that the other oxygen atom in trans-1,2-dihydroxy-1,2-dihydronaphthalene was derived from water. Mass spectral analysis of the acid-catalyzed dehydration products of the dihydrodiol indicated that the naphthalene dihydrodiol forms via the addition of water at the C-2 position of naphthalene-1,2-oxide. Fungal metabolism of [1-2H]naphthalene yielded 1-naphthol which retained 78% of the deuterium. NMR analysis of the deuterated 1-naphthol indicated an NIH shift mechanism in which deuterium migrated from the C-1 position to the C-2 position. The above results indicate that naphthalene-1,2-oxide is an intermediate in the fungal metabolism of naphthalene and that the fungal enzymes are highly stereo-selective in the formation of trans-1,2-dihydroxy-1,2-dihydronaphthalene.
本文描述了丝状真菌秀丽小克银汉霉氧化萘的机制。秀丽小克银汉霉将萘主要氧化为反式 - 1,2 - 二羟基 - 1,2 - 二氢萘。通过500兆赫的核磁共振（NMR）光谱确定了二氢二醇的反式构型，其显示出11.0赫兹的大耦合常数（J1,2）。将真菌的反式 - 1,2 - 二羟基 - 1,2 - 二氢萘的圆二色光谱与哺乳动物酶系统形成的光谱进行比较，表明真菌二氢二醇含有76%的（+） - （1S,2S） - 二氢二醇作为主要对映体。秀丽小克银汉霉形成的其他萘代谢物被鉴定为1 - 萘酚、2 - 萘酚和4 - 羟基 - 1 - 四氢萘。用萘和18O2培养秀丽小克银汉霉表明，反式 - 1,2 - 二羟基 - 1,2 - 二氢萘含有一个分子氧原子，这表明是单加氧酶催化的反应，而用萘和H182O进行类似培养表明，反式 - 1,2 - 二羟基 - 1,2 - 二氢萘中的另一个氧原子来自水。对二氢二醇酸催化脱水产物的质谱分析表明，萘二氢二醇是通过在萘 - 1,2 - 环氧化物的C - 2位加水形成的。[1 - 2H]萘的真菌代谢产生了保留78%氘的1 - 萘酚。对氘代1 - 萘酚的NMR分析表明存在NIH迁移机制，其中氘从C - 1位迁移到C - 2位。上述结果表明，萘 - 1,2 - 环氧化物是真菌代谢萘的中间体，并且真菌酶在形成反式 - 1,2 - 二羟基 - 1,2 - 二氢萘时具有高度的立体选择性。
