Biotransformation of Nitriles by Marine Fungi 28.4 Conclusion 705
Part E | 28.4
yield of the biotransformed product, the cyclohexenylacetic acid 5a (28%). We conclude that the marine
fungus A. sydowii CBMAI 934 induced by phenylacetonitrile 1 in a mineral medium was also effective in
transforming a nitrile group linked to a non-aromatic
sp
3 carbon atom.
28.3.4 Biotransformation of Aromatic
and Hetero(aromatic) Nitriles by the
Marine Fungus A. sydowii CBMAI 934
To observe the behavior of the cyano group connected directly to the aromatic ring, experiments were
carried out on eight aromatic nitriles: benzonitrile
6, 2-chlorobenzonitrile 7, 4-hydroxybenzonitrile 8, 4methoxybenzonitrile 9, 3,5-dimethoxybenzonitrile 10,
2-nitrobenzonitrile 11, 3-nitrobenzonitrile 12, and 4nitrobenzonitrile 13. In these tests, no biotransformation of any these aromatic nitriles occurred with
the phenylacetonitrile-induced by fungus A. sydowii
CBMAI 934.
In order to extend the application of the mycelium
of the fungus A. sydowii CBMAI 934 induced by the
presence of phenylacetonitrile 1, the biotransformation
reaction was performed in a mixture of benzonitrile 6
and 2-cyanopyridine 14 (Table 28.5). Surprisingly, all
three substrates were biotransformed. Phenylacetonitrile 1 was converted to 2-hydroxyphenylacetic acid 1a
and 2-cyanopyridine 9 to 2-pyridinecarboxamide 14a
(Fig. 28.41). Benzonitrile 10 was possibly catalyzed to
benzoic acid, but it was not possible to identify this reaction product.
Šnajdrová et al. reported that the benzonitrile 6 was
the best substrate for biotransformation to its corresponding carboxylic acid; however, the benzoic acid
formed was consumed by the fungus Aspergillus niger
during the reaction [28.60]. Interestingly, benzonitrile 6
was biotransformed by A. sydowii CBMAI 934 in the
presence of phenylacetonitrile 1 and 2-cyanopyridine
14, whereas this biotransformation in the presence of
phenylacetonitrile 1 alone was not possible.
In part, our results with the fungus A. sydowii CBMAI 934 corroborate studies performed by Martínková
et al. that confirmed that 2-cyanopyridine 14 may act
as a universal inducer in biotransformations of aromatic nitriles by filamentous fungi [28.30]. In our case,
both phenylacetonitrile 1 and 2-cyanopyridine 14 may
have acted as inducers in the biotransformation of
benzonitrile 6.
Another reaction was carried out on 2-cyanopyridine 14, in the absence of benzonitrile 6, which confirmed that phenylacetonitrile 1 induced the biotransformation of 2-cyanopyridine 14 (Fig. 28.42, Table 28.6).
The biotransformation of 2-cyanopyridine 14 was
confirmed by comparative analysis with the synthetic
standard in GC-FID (Figs. 28.41–28.42) and by analysis in GC-MS (Fig. 28.43).
Additionally, in a reaction carried out with the fungus A. sydowii CBMAI 934, it was previously grown on
agar plates for 8 days in the presence of 2-cyanopyridine 14 (5:0 L, 0:052 mmol per plate) which restricted
growth on the plate. However, without phenylacetonitrile 1 the biotransformation of the 2-cyanopyridine 14
in liquid medium was not observed. The 2-cyanopyridine 14 remained in the reaction medium.
Thus, the phenylacetonitrile 1 was essential to
the biotransformation of 2-cyanopyridine 14 to 2pyridinecarboxamide 14a and, under in these conditions the marine fungus A. sydowii CBMAI 934 demonstrated its ability to hydrolyze, of hetero(aromatic)
nitriles.
Thus, we conclude that the selective biotransformation by fungus A. sydowii CBMAI 934 induced
with phenylacetonitrile 1 may be used to hydrolyze
arylaliphatic 1-4, aliphatic 5, and hetero(aromatic) 14
nitriles.
28.4 Conclusion
By screening 12 strains of marine fungi on solid mineral
medium supplemented with glucose and phenylacetonitrile 1, as the only nitrogen source, it was possible to
select 8 of these strains, all of which showed good
growth in liquid mineral medium in the presence of
20:0, 40:0, and 60:0 L phenylacetonitrile 1. In control
experiments (without phenylacetonitrile) there was no
microbial growth, demonstrating the ability of phenylacetonitrile 1 to induce the growth of these microorganisms, acting as the sole nitrogen source.
The phenylacetonitrile 1 was biotransformed to 2hydroxyphenylacetic acid 1a, showing that the fungi
selected had the potential to biotransform derivatives of
phenylacetonitrile 1.
The direct biotransformation of nitriles 2–5 to the
corresponding carboxylic acids 2a–5a suggests the en-
Part E | 28.4
yield of the biotransformed product, the cyclohexenylacetic acid 5a (28%). We conclude that the marine
fungus A. sydowii CBMAI 934 induced by phenylacetonitrile 1 in a mineral medium was also effective in
transforming a nitrile group linked to a non-aromatic
sp
3 carbon atom.
28.3.4 Biotransformation of Aromatic
and Hetero(aromatic) Nitriles by the
Marine Fungus A. sydowii CBMAI 934
To observe the behavior of the cyano group connected directly to the aromatic ring, experiments were
carried out on eight aromatic nitriles: benzonitrile
6, 2-chlorobenzonitrile 7, 4-hydroxybenzonitrile 8, 4methoxybenzonitrile 9, 3,5-dimethoxybenzonitrile 10,
2-nitrobenzonitrile 11, 3-nitrobenzonitrile 12, and 4nitrobenzonitrile 13. In these tests, no biotransformation of any these aromatic nitriles occurred with
the phenylacetonitrile-induced by fungus A. sydowii
CBMAI 934.
In order to extend the application of the mycelium
of the fungus A. sydowii CBMAI 934 induced by the
presence of phenylacetonitrile 1, the biotransformation
reaction was performed in a mixture of benzonitrile 6
and 2-cyanopyridine 14 (Table 28.5). Surprisingly, all
three substrates were biotransformed. Phenylacetonitrile 1 was converted to 2-hydroxyphenylacetic acid 1a
and 2-cyanopyridine 9 to 2-pyridinecarboxamide 14a
(Fig. 28.41). Benzonitrile 10 was possibly catalyzed to
benzoic acid, but it was not possible to identify this reaction product.
Šnajdrová et al. reported that the benzonitrile 6 was
the best substrate for biotransformation to its corresponding carboxylic acid; however, the benzoic acid
formed was consumed by the fungus Aspergillus niger
during the reaction [28.60]. Interestingly, benzonitrile 6
was biotransformed by A. sydowii CBMAI 934 in the
presence of phenylacetonitrile 1 and 2-cyanopyridine
14, whereas this biotransformation in the presence of
phenylacetonitrile 1 alone was not possible.
In part, our results with the fungus A. sydowii CBMAI 934 corroborate studies performed by Martínková
et al. that confirmed that 2-cyanopyridine 14 may act
as a universal inducer in biotransformations of aromatic nitriles by filamentous fungi [28.30]. In our case,
both phenylacetonitrile 1 and 2-cyanopyridine 14 may
have acted as inducers in the biotransformation of
benzonitrile 6.
Another reaction was carried out on 2-cyanopyridine 14, in the absence of benzonitrile 6, which confirmed that phenylacetonitrile 1 induced the biotransformation of 2-cyanopyridine 14 (Fig. 28.42, Table 28.6).
The biotransformation of 2-cyanopyridine 14 was
confirmed by comparative analysis with the synthetic
standard in GC-FID (Figs. 28.41–28.42) and by analysis in GC-MS (Fig. 28.43).
Additionally, in a reaction carried out with the fungus A. sydowii CBMAI 934, it was previously grown on
agar plates for 8 days in the presence of 2-cyanopyridine 14 (5:0 L, 0:052 mmol per plate) which restricted
growth on the plate. However, without phenylacetonitrile 1 the biotransformation of the 2-cyanopyridine 14
in liquid medium was not observed. The 2-cyanopyridine 14 remained in the reaction medium.
Thus, the phenylacetonitrile 1 was essential to
the biotransformation of 2-cyanopyridine 14 to 2pyridinecarboxamide 14a and, under in these conditions the marine fungus A. sydowii CBMAI 934 demonstrated its ability to hydrolyze, of hetero(aromatic)
nitriles.
Thus, we conclude that the selective biotransformation by fungus A. sydowii CBMAI 934 induced
with phenylacetonitrile 1 may be used to hydrolyze
arylaliphatic 1-4, aliphatic 5, and hetero(aromatic) 14
nitriles.
28.4 Conclusion
By screening 12 strains of marine fungi on solid mineral
medium supplemented with glucose and phenylacetonitrile 1, as the only nitrogen source, it was possible to
select 8 of these strains, all of which showed good
growth in liquid mineral medium in the presence of
20:0, 40:0, and 60:0 L phenylacetonitrile 1. In control
experiments (without phenylacetonitrile) there was no
microbial growth, demonstrating the ability of phenylacetonitrile 1 to induce the growth of these microorganisms, acting as the sole nitrogen source.
The phenylacetonitrile 1 was biotransformed to 2hydroxyphenylacetic acid 1a, showing that the fungi
selected had the potential to biotransform derivatives of
phenylacetonitrile 1.
The direct biotransformation of nitriles 2–5 to the
corresponding carboxylic acids 2a–5a suggests the en-