Synthesis and biological activity of Schiff bases derived from dehydroabietylamine and benzaldehyde derivatives

Article abstract of DOI:10.1134/S1070427207080216

Previously unknown Schiff bases were prepared from dehydroabietylamine and substituted benzaldehydes. Their physicochemical properties were determined, and the bactericidal activity toward some microorganisms was evaluated.

Full text of DOI:10.1134/S1070427207080216

ISSN 1070-4272, Russian Journal of Applied Chemistry, 2007, Vol. 80, No. 8, pp. 1373 1375.
Pleiades Publishing, Ltd., 2007.
Original Russian Text
No. 8, pp. 1334 1336.
Xiaoping Zhao, Dzen Kwang Song, A.B. Radbil’, B.A. Radbil’, 2007, published in Zhurnal Prikladnoi Khimii, 2007, Vol. 80,
ORGANIC SYNTHESIS
AND INDUSTRIAL ORGANIC CHEMISTRY
Synthesis and Biological Activity of Schiff Bases Derived
from Dehydroabietylamine and Benzaldehyde Derivatives
Xiaoping Zhao, Dzen Kwang Song, A. B. Radbil’, and B. A. Radbil’
Institute of Chemical Processing of Wood Products, Academy of Wood
of Chinese People’s Republic, Nankin, China
Lesma Research and Promotion Firm, Limited Liability Company, Nizhni Novgorod, Russia
Received January 1, 2007
Abstract Previously unknown Schiff bases were prepared from dehydroabietylamine and substituted
benzaldehydes. Their physicochemical properties were determined, and the bactericidal activity toward some
microorganisms was evaluated.
DOI: 10.1134/S1070427207080216
Schiff bases derived from primary amines and
substituted benzaldehydes exhibit antibacterial, anti-
cancer, and antitumor activity. Numerous studies have
shown that such an activity of Schiff bases is caused
by the presence of the >C=N functional group. It is
also known [1] that many amines derived from resin
(diterpene) acids exhibit a wide spectrum of biological
activity. In particular, Borglin has shown that dehy-
droabietylamine is an effective bactericidal and fungi-
cidal agent [2]. It would be expected that Schiff bases
derived from dehydroabietylamine will exhibit en-
hanced biological activity. However, data on the syn-
thesis and properties of Schiff bases derived from
dehydroabietylamine are lacking.
R
CHO
R
H3C CH2N C
H3C CH2NH2
R
+
EtOH
R
CH3
CH3
CH3
H3C
H3C
CH3
where R = R = H (a); R = H, R = p-OMe (b); R = H,
R = p-Cl (c); R = H, R = p-F (d); R = H, R = o-OH
(e); R = o-OH, R = p-NO2 (f); R = o-OH, R = p-Cl
(g); R = o-OH, R = p-OMe (h).
The rate of this reaction is fairly high. All the
Schiff bases precipitate from the reaction mixture
virtually immediately after the reactants solutions are
mixed. They are insoluble in water and in ethanol
at room temperature and soluble in dimethylform-
amide, chloroform, dimethyl sulfoxide, and some
other solvents.
Here we report on the synthesis and biological ac-
tivity of Schiff bases derived from dehydroabietyl-
amine and substituted benzaldehydes. These Schiff
bases were prepared in high yields (85 95%) by direct
condensation in ethanol:
Table 1. Physicochemical properties of the Schiff bases
Found, %
H
Calculated, %
H
Com-
pound
Empirical
formula
Color
White
Tm,
C
C
N
C
N
a
b
c
d
e
f
C27H35N
104.5
86.22
84.94
79.54
82.78
82.84
74.39
76.11
79.84
9.49
9.86
8.28
9.40
9.51
8.36
8.50
9.23
3.61
3.11
3.25
3.19
3.75
6.44
3.17
3.36
86.86
83.79
79.50
82.86
82.86
75.34
75.96
79.43
9.39
9.23
8.34
8.69
8.95
7.91
7.97
8.75
3.75
3.49
3.44
3.58
3.58
6.51
3.28
3.31
C28H37NO
C27H34NCl
C27H34NF
C27H35NO
C27H34N2O3
C27H34NOCl
C28H37NO2
103.5
118.6
106.5
153.2
187.5
177.8
105.2
Yellow
Red
g
h
1373

1374
XIAOPING ZHAO et al.
1
The physicochemical parameters of the azometh-
ines prepared are listed in Table 1.
tions at 3460 3410 cm . In the spectra of the other
compounds, this band is absent.
1
In the H NMR spectra, the N=C H signal is
The structures of the compounds were confirmed
by IR and H NMR spectroscopy (Table 2). The IR
1
observed at 8.2 8.4 ppm, and the OH signal, at 13.6
15.0 ppm.
spectra of all the compounds contain a strong absorp-
1
tion band of the >C=N group at 1660 1610 cm .
The bactericidal activity of the compounds was
studied with test cultures of E. Coli, B. Subtilis,
and S. Aureus. The activity was evaluated by the di-
ameter of the inhibition zone (cm) arising 48 h after
Its position only slightly depends on the structure of
the compound and on substituents in the phenyl ring
of the benzaldehyde moiety. The spectra of e h also
contrain a well-defined band of OH stretching vibra-
6
1
introducing into the cultural medium 2 10 g ml
Table 2. Spectroscopic characteristics of the Schiff bases
1
Compound
IR spectrum, , cm
1H NMR spectrum, , ppm
a
2931, 1644, 1040, 832
8.265 (1H, N=CH ); 7.765, 7.423, 7.2204, 7.024, 6.906 (8H,
C=CH ); 3.536 (1H, N CH2 ); 2.879 [1H, CH(CH3)2]; 2.858,
2.303, 1.967, 1.794, 1.579 (10H, CH2 ); 1.485 (1H, >CH );
1.271, 1.258, 1.084 (9H, CH3)
b
c
d
e
f
2938, 1645, 1086, 823
8.224 (1H, N=CH ); 7.692, 7.391, 7.223, 7.032, 6.910 (7H,
C=CH ); 3.527 (1H, N CH2 ); 2.898 [1H, CH(CH3)2]; 2.851,
2.319, 1.939, 1.790, 1.528 (10H, CH2 ); 1.439 (1H, >CH );
1.272, 1.265, 1.008 (9H, CH3)
2944, 1645, 1036, 825
8.207 (1H, N CH2 ); 7.725, 7.246, 7.225, 7.026, 6.938 (7H,
C=CH ); 3.884 (1H, N CH2 ); 3.868 (3H, OCH3); 3.541 [1H,
CH(CH3)2]; 3.389, 2.902, 2.367, 1.743, 1.715 (10H, CH2 );
1.498 (1H, >CH ); 1.475, 1.298, 1.086 (9H, CH3)
2941, 1650, 1229, 831
8.249 (1H, N CH2 ); 7.763, 7.282, 7.227, 7.091, 6.934 (7H,
C=CH ); 3.547 (1H, N CH2 ); 2.919 [1H, CH(CH3)2]; 2.879,
2.315, 1.847, 1.724, 1.456 (10H, CH2 ); 1.456 (1H, >CH );
1.309, 1.281, 1.092 (9H, CH3)
3442, 2937, 1628, 1153, 759
3423, 2935, 1618, 1330, 1098
3459, 2935, 1639, 1991, 826
3452, 2934, 1629, 1076, 832
13.619 (1H, OH); 8.336 (1H, N CH2 ); 7.349, 7.300, 7.209,
7.023, 6.879 (6H, C=CH ); 3.530 (1H, N CH2 ); 2.864 [1H,
CH(CH3)2]; 2.313, 1.837, 1.806, 1.585, 1.503 (10H, CH2 );
1.412 (1H, >CH ); 1.281, 1.243, 1.079 (9H, CH3)
14.982 (1H, OH); 8.342 (1H, N CH2 ); 7.282, 7.204, 7.031,
6.979, 6.914 (6H, C=CH ); 3.523 (1H, N CH2 ); 2.843 [1H,
CH(CH3)2]; 2.325, 1.877, 1.854, 1.565, 1.421 (10H, CH2 );
1.410 (1H, >CH ); 1.279, 1.234, 1.099 (9H, CH3)
g
h
13.572 (1H, OH); 8.268 (1H, N CH2 ); 7.283, 7.234, 7.024,
7.004, 6.904 (6H, C=CH ); 3.538 (1H, N CH2 ); 2.861 [1H,
CH(CH3)2]; 2.333, 1.835, 1.807, 1.579, 1.435 (10H, CH2 );
1.402 (1H, >CH ); 1.274, 1.257, 1.073 (9H, CH3)
14.167 (1H, OH); 8.369 (1H, N CH2 ); 7.282, 7.172, 7.011,
6.943, 6.799 (6H, C=CH ); 3.913 (3H, OCH3); 3.549 (1H,
N CH2 ); 2.842 [1H, CH(CH3)2]; 2.308, 1.802, 1.630, 1.500,
1.448 (10H, CH2 ); 1.414 (1H, >CH ); 1.273, 1.243, 1.073
(9H, CH3)
RUSSIAN JOURNAL OF APPLIED CHEMISTRY Vol. 80 No. 8 2007

SYNTHESIS AND BIOLOGICAL ACTIVITY OF SCHIFF BASES
Table 3. Bactericidal activity of Schiff bases
Diameter of the inhibition zone, cm, for indicated compound
1375
Bacteria
a
b
c
d
e
f
g
h
S. Aureus
B. Subtilis
E. Coli
1.05
0.95
1.15
0.95
1.20
1.01
1.20
1.72
1.12
1.65
1.32
0.90
0.90
0.85
0.90
1.25
0.90
0.80
1.10
1.20
0.85
1.10
0.90
0.92
solutions of the Schiff bases in dimethylformamide
(Table 3).
tive in 100 ml of ethanol was slowly added from the
dosing unit. The mixture was stirred for 3 h at 20 C.
The crystals of the Schiff bases were filtered off,
recrystallized three times from ethanol, and dried in
a vacuum.
All the compounds prepared exhibit bactericidal
activity. Compound c derived from Cl-substituted
benzaldehyde is the most active toward B. Subtilis
(diameter of inhibition zone 1.72 cm), and compound
d derived from fluorinated benzaldehyde, toward
S. Aureus (diameter of inhibition zone 1.65 cm). It
should be noted that the most active agent toward
E. Coli is compound a derived from unsubstituted
benzaldehyde (diameter of inhibition zone 1.15 cm);
introduction of substituents into the benzaldehyde
moiety does not enhance the bactericidal activity of
the Schiff base.
The bactericidal activity of each of the Schiff bases
synthesized was evaluated by measuring the diameter
of the inhibition zone [3, 4]. For this purpose, 0.5 ml
of a suspension of spores of each test culture was
added to a sterile agarized cultural medium just before
its solidification, after which the mixture was poured
into sterile Petri dishes (9 cm in diameter) and al-
lowed to solidify. Solutions of the Schiff bases in
6
1
dimethylformamide (2 10 g ml ) were prepared.
Then sterile disks made of filter paper (7 mm in diam-
eter) were wetted in a solution of appropriate Schiff
base and placed into the Petri dishes. The Petri dishes
were kept at 35 C for 48 h, after which the inhibition
zones of bacterial growth were revealed and the diam-
eter of each zone was measured. Three replicate ex-
periments were performed with each Schiff base.
Thus, introduction of substituents into the phenyl
ring of the benzaldehyde moiety appreciably affects
the bactericidal activity of Schiff bases. However, this
effect is ambiguous and depends on numerous factors,
primarily on the structure of the molecule, presence
and nature of substituents in the dehydroabietylamine
and benzaldehyde moieties, and particular microor-
ganism.
CONCLUSION
EXPERIMENTAL
The Schiff bases synthesized from abietylamine
and substituted benzaldehydes exhibit noticeable bac-
tericidal activity toward certain microorganisms.
The correlation between the molecular structure
and biological activity is ambiguous.
All the chemicals used for preparing Schiff bases
(dehydroabietylamine; benzaldehyde and its deriva-
tives) were of chemically pure or analytically pure
grade and were used without additional purification.
Elemental analysis was performed with an RE-
2400CHN device. The IR spectra were recorded on a
Bio-Rad FTS-185 IR spectrophotometer using KBr
REFERENCES
1. Sandermann, W., Naturharze Terpentinol-Tallol. Chemie
und Technologie, Berlin: Springer, 1960. Translated
under the title Prirodnye smoly, skipidar, tallovoe
maslo, Moscow: Lesnaya Prom st., 1964, pp. 303 310.
1
cells. The H NMR spectra were measured on a DPX-
300 Bruker Avance 300 spectrometer (solvent CDCl3,
reference TMS). The melting points were determined
with an XT-5 device.
2. Borglin, S., Soap Sanit. Chem., 1947, vol. 23, no. 12,
pp. 147 149, 169.
Syntheses were performed in a vessel equipped
with a stirrer, reflux condenser, and dosing unit.
The vessel was charged with a solution of 10 mmol of
dehydroabietylamine in 200 ml of ethanol, after which
a solution of 10 mmol of benzaldehyde or its deriva-
3. Alzoreky, N.S. and Nakahara, K., Int. J. Food Micro-
biol., 2003, vol. 80, pp. 223 230.
4. Sari, N., Arslan, S., Logoglu, E., and Sakiyan, I.,
J. Sci., 2003, vol. 16, p. 283.
RUSSIAN JOURNAL OF APPLIED CHEMISTRY Vol. 80 No. 8 2007