Synthesis, biological study and complexation behavior of some anionic schiff base amphiphiles

Article abstract of DOI:10.1007/s11743-010-1206-7

A novel series of anionic Schiff base amphiphiles were synthesized. The chemical structures of these compounds were elucidated using different spectroscopic tools. The surface and thermodynamic properties of the prepared Schiff bases were studied using classical measurements including surface and interfacial tensions. The surface parameters of these compounds, e.g., surface tension, critical micelle concentration, effectiveness, efficiency, maximum surface excess, minimum surface area, and interfacial activity showed their good surface activity. Their thermodynamic parameters of adsorption and micellization including free energy change of micellization and adsorption showed their tendency toward adsorption at the interfaces and also micelle formation at lower concentrations. The complexation behavior of the synthesized Schiff bases were study through the interaction of the Schiff base (IIIa; SBSD) with nickel chloride hexahydrate. All synthesized compounds in addition to NiCl₂.6H₂O and Ni Schiff Base complex have been evaluated for their antibacterial activity against Gram-positive and Gram-negative bacteria. The results of the biocidal activities showed high potent action of (Ni-III_a; Ni-SBSD) complex more than Schiff base IIIa; SBSD. AOCS 2010.

Full text of DOI:10.1007/s11743-010-1206-7

J Surfact Deterg (2010) 13:423–431
DOI 10.1007/s11743-010-1206-7
ORIGINAL ARTICLE
Synthesis, Biological Study and Complexation Behavior of Some
Anionic Schiff Base Amphiphiles
Fatma H. Abdel-Salam
Received: 8 January 2010 / Accepted: 17 April 2010 / Published online: 16 May 2010
Ó AOCS 2010
Abstract A novel series of anionic Schiff base amphi-
philes were synthesized. The chemical structures of these
compounds were elucidated using different spectroscopic
tools. The surface and thermodynamic properties of
the prepared Schiff bases were studied using classical
measurements including surface and interfacial tensions.
The surface parameters of these compounds, e.g., surface
tension, critical micelle concentration, effectiveness, effi-
ciency, maximum surface excess, minimum surface area,
and interfacial activity showed their good surface activity.
Their thermodynamic parameters of adsorption and mic-
ellization including free energy change of micellization and
adsorption showed their tendency toward adsorption at the
interfaces and also micelle formation at lower concentra-
tions. The complexation behavior of the synthesized Schiff
bases were study through the interaction of the Schiff base
(IIIa; SBSD) with nickel chloride hexahydrate. All syn-
thesized compounds in addition to NiCl2ꢀ6H2O and Ni
Schiff Base complex have been evaluated for their anti-
bacterial activity against Gram-positive and Gram-negative
bacteria. The results of the biocidal activities showed high
potent action of (Ni-IIIa; Ni-SBSD) complex more than
Schiff base IIIa; SBSD.
Introduction
Schiff bases are organic compounds with great utility in
important fields such as medicine, agriculture, and cos-
metic products [1–3]. Some Schiff bases present antican-
cer, antitumor and antibacterial activity [4–7]. They play a
prominent part in the enzymatic or unenzymatic transa-
minating reactions of the carbonyl compounds with amino
acids [8]. In the coordinate chemistry field, a lot of Schiff
bases operate as ligands [9]. Coordination compounds
exhibit different characteristic properties which depend on
the metal ion on to which they are bound, the nature of the
metal as well as the type of ligand. These metal complexes
have found extensive applications in various fields of
human interest [10–15]. Various studies [16–18] have
shown a relationship between the metal ions and their
metal complexes as antitumor and antibacterial agents
which is a subject of great interest. It was seen that the
biological active compounds become more bacteriostatic
and carcinostatic upon chelation with metal ions [19].
In the present paper, different self-assembled anionic
Schiff bases IIIa–d in addition to an Ni-SBSD complex were
synthesized. The surface and antibacterial activities were
discussed.
Keywords Schiff base amphiphiles ꢀ Nickel complex ꢀ
Surface ꢀ Antibacterial activities
Experimental
All chemicals used in the present investigation were of
Analar or highest purity grade from the BDH, Aldrich and
Merck companies and used as received without further
purification. FTIR spectra were recorded on a Perkin-Elmer
1420 spectrometer and a biorad FT 57 (KBr). A Bruker
model DRX-300 NMR spectrometer with TMS as an
internal standard for 1H-NMR spectra was used. Mass
F. H. Abdel-Salam (&)
Chemistry Department, Faculty of Science,
Al-Azhar University (Girls), PO Box 11754, Cairo, Egypt
e-mail: Prof_drfatma@yahoo.com
123

424
J Surfact Deterg (2010) 13:423–431
spectra were recorded on a JEO1 JMS-AX 500 (EI and
FAB?). The elemental analyses of the synthesized mate-
rials were performed using a Vario Elementar instrument
for elemental analysis.
extracted with 60 ml of diethyl ether several times. The
collected ether layer was dried over anhydrous sodium
sulfate to dryness to yield IIa,b, Scheme 1.
IR spectrum (IIa): 826 (Ar.nucleus), 2,836 (CH2), 2,921
1
(CH3) and 3,457 (NH2) cm-1. H NMR (CDCl3): 0.88 (t,
Synthesis of Potassium Salt of 2-Carboxymethyl
Benzaldehyde and 2-Methoxy-3-Carboxymethyl
3H, CH3), 1.21–1.27 [m,22H, (CH2)11], 7.52 (d.d, phenyl
ring, 4H) and d 9.53 (s, 2H, NH2). FAB-MS (m/z): 261.26
(M?) (41.23%), Fig. 1.
Benzaldehyde (Ia,b
)
An aromatic aldehyde namely, salicyaldehyde and vanillin
(0.1 mol) was stirred with an alcoholic potassium hydroxide
solution (5 ml, 0.1 mol) and ethanol (20 ml). Potassium
chloroacetic solution (0.15 mol) was added drop wise. The
pH of the liquid mixture was adjusted with triethylamine, the
mixture was refluxed for 6 h under a nitrogen atmosphere.
This reaction mixture was allowed to cool to room
temperature, then poured onto crushed ice. The product
was extracted with ethyl acetate. The crude Ia,b was re-
crystallized several times from 60% ethanol solution to
give Ia,b (Table 1). IR (KBr pellet): 1,720 (C = O), 1,282
(C–O–C), another band at 832-893 cm-1 corresponding to
the benzene nucleus for compounds Ia,b and characteristic
Synthesis of Anionic Schiff Bases Amphiphiles (IIIa–d
)
In a conical flask, 0.5 mol of Ia,b was condensed with 0.5 mol
of IIa,b in presence of 100 ml ethyl alcohol as a solvent. The
pH was adjusted from 7 to 8 by triethylamine. The reaction
mixture was refluxed for 6 h and left overnight in refrigerator
until the product precipitated. The product was washed with
hexane and recrystallized from acetone, the final product was
dried under a vacuum at 40 °C. The Schiff bases (SB) pro-
duced whose chemical formulas are indicated in Table 1, are
denoted as SBSD, SBSS, SBVD, SBVS for potassium salts
of either (4-alkyl-1-benzyl imino) 2-carboxy methyl ben-
zene or (4-alkyl-1-benzyl imino) 2-methyl-3-carboxy
methyl benzene which derived from salicyaldehyde and
vanillin with 4-aminoalkyl benzene respectively, and their
chemical structures are shown in Scheme 1.
1
absorption band appears at 2,836 cm-1 (OCH3) for Ib. H
NMR (CDCl3) for Ia showed that d 9.85 (s, 1H, CHO), d
7.02–7.62 (m, 4H,Ar–H) and d 4.91 (s,2H,CH2).
Synthesis of 4-Amino Alkyl Benzene IIa,b
Microelemental analysis of the synthesized Schiff bases
showed their purity (Table 1).
IR spectra showed absorption at 850–890 cm-1 corre-
sponding to the benzene nucleus and band at 1,210 cm-1
indicating the presence of an ether linkage (–C–O–C)–.
The appearance of a strong new band at 1,635 cm-1
determines the formation of an azomethene. (HC = N)
linkage and disappearance of the band at 3,457 due to the
(NH2) group.1H NMR (CDCl3) for IIIc; d 8.32 (s, 1H,
CH = N), d 7.60 (m, 7H, Ar–H), 4.16–4.19 (s, 2H,
OCH2-), d 3.91 (s, 3H, OCH3), 1.1–1.2 (m, 22H, (CH2)11)
Fatty alcohol C12, C18 (0.46 mol), aniline (0.46 mol), ani-
line hydrochloride (0.14 mol) and anhydrous zinc chloride
(0.32 mol) were heated in a conical flask equipped with a
Dean Stark apparatus to collect the water of the reaction.
The reaction mixture was heated for 1 h at 240–250 °C,
excess zinc chloride and 4-amino alkyl benzene hydro-
chloride were removed by adding 40% sodium hydroxide
solution (200 ml) to the reaction mixture which was heated
at 70 °C for 2 h. The reaction mixture was left to cool and
Table 1 Analytical data of the prepared Schiff bases and Ni-SBSD complex
Compound
Molecular formula
m.p. °C
Molecular weight
Calculated/Found
Ni%
C
H
N
SBSD
C27H35NO3K
Waxy
60–62
Waxy
72–74
130–32
460.68
544.84
491.71
575.87
940.01
70.40
70.19
72.75
72.56
68.40
68.21
70.91
70.78
68.99
68.71
7.66
7.42
8.69
8.42
7.79
7.62
8.75
8.61
7.66
7.45
3.04
2.87
2.57
2.29
2.85
2.63
2.43
2.32
2.98
2.74
–
–
–
–
SBSS
C33H47NO3K
C28H38NO4K
C34H50NO4K
SBVD
SBVS
Ni-SBSD
Ni.C54H72N2O6ꢀ2H2O
6.24
6.13
123

J Surfact Deterg (2010) 13:423–431
425
Scheme 1 Synthetic route of
the synthesized anionic Schiff
base amphiphiles
CHO
CHO
(i)
OCH2COOK
and
OH
Ia
Et3N
ClCH2COOK
+
CHO
and
CHO
OCH3
OCH3
OH
OCH2COOK
Ib
NH2
NH2
C6H5NH2.HCl
ZnCl2 anh.
(ii)
+ ROH
R
a: R = CH3.(CH2)11
IIa,b
b: R =
CH3.(CH2)17
NH2
CHO
R'
R''
OCH2COOK
(iii)
+
N=CH
R
CHO
OCH3
R
IIIa-d
OCH2COOK
a, R' = OCH2COOK, R = CH3–(CH2)11 , R'' = H
b, R' = OCH2COOK, R = CH3–(CH2)17 , R'' = H
(SBSD)
(SBSS)
(SBVD)
(SBVS)
c, R' = OCH3,
d, R' = OCH3,
R = CH3–(CH2) 11 , R'' = OCH2COOK
R = CH3–(CH2)17 , R'' = OCH2COOK
Fig. 1 Mass spectra of IIa
and d 0.9 (t, 3H, CH3). EI/FAB? (m/z): 491% (M-1)
(14.07%) for IIIc, Fig. 2.
A hot ethanolic solution of NiCl2ꢀ6H2O (0.01 mol) was
added dropwise to a hot ethanolic solution of Schiff base
ligand, SBSD (0.02 mol). After complete addition, the
reaction mixture was heated under reflux with continuous
stirring for 2 h. On cooling at room temperature, the nickel
complex was separated and filtered under suction. The
crude complex was washed several times with ethanol
followed by diethylether and dried in a vacuum desiccator
Synthesis of the Metal Complex
All the Schiff base ligands (SBSD, SBSS, SBVD and
SBVS) have similar structures, so the Schiff base ligand
SBSD was selected to study their behavior towards metal
ions. In a typical procedure:
123

426
J Surfact Deterg (2010) 13:423–431
Fig. 2 Mass spectra of IIIc
over fused calcium chloride. In order to give conclusive
idea about the structure of the nickel complex, the main IR
bands was compared with those of the free ligands.
Absorption band at 1,621 cm-1 for CH = N which
shifted to a lower frequency than Schiff base itself. This
indicated that it may be considered as a center of chelation
[20]. EI/FAB? (m/z) for Ni-SBSD 938 (M?-2) (3.78%)
Fig. 3. The nickel content was determined by titration
against a standard EDTA solution after complete decom-
position of the complex [21].
measurements were carried out for 0.1 mol/L surfactant
solutions against benzene at 25 °C [22].
Antimicrobial Activity
The synthesized anionic Schiff base amphiphiles and the
nickel complex were screened for their antimicrobial
activity against bacteria using agar well diffusion methods
[23]. Bacteria species used in this study were Staphylo-
coccus aureus (ATCC 25923), Streptococcus pyogenes
(ATCC 19615) as Gram-positive and Pseudomonas
phaseolicola (GSPB 2828), Pseudomonas fluorescens
(S97) as Gram-negative bacteria.
Surface and Interfacial Tension Measurements
Surface tension (ST) measurements were performed for
freshly prepared solutions of surfactants. The concentration
ranges from 10-1 to 10-6 mol/l using a Du-Nouy tensi-
ometer at 25 °C. Also, interfacial tension (IT)
Thermal Gravimetric Analyses (TGA)
Thermal gravimetric analyses (TGA) of the Ni-SBSD
complex were obtained in a nitrogen atmosphere using a
Fig. 3 Mass spectra of the
nickel complex for [Ni-
(SBSD)2]ꢀ2H2O complex
123

J Surfact Deterg (2010) 13:423–431
427
type SDTQ 600 universal V4-5A thermal analyzer. The
heating rates were suitably controlled at 10 °C/min under a
nitrogen atmosphere and the weight loss was measured
from room temperature up to 1,000 °C.
31.70% (theoretical 31.56%), leaving behind nickel nitrate
as the residue of the decomposition. The overall weight
loss 81.40% (theoretical 80.99%). So, the suggested
structure of the metal complex is shown in Scheme 2.
Surface Activity
Results and Discussion
Figures 5 and 6 represent the relation between the surface
tension and the logarithm of the concentration (mol/L) of
the synthesized anionic Schiff base amphiphiles at 25 °C. It
is clear that the surface tension profile has the character-
istics of anionic surfactants including the relatively lower
surface tension values ranging from 32 to 37 mN/m. Also,
it could be observed that increasing the number of meth-
ylene group along the hydrophobic chains decreases the
critical micelle concentration (CMC) considerably [24].
That effect was explained in a previous work [25–27] due
to the repulsion occurred between the hydrophobic chains
(non polar phase) and the water phase (polar phase), which
forced the molecules to adsorb at the air water interface
and to micellize in the bulk of their solutions in order to
decrease that repulsion. The same trend was observed in
the vanillin series. The highest CMC values were observed
for SBVD at 11.22 9 10-3 mol/l, while the lowest value
was observed for SBSS at 3.16 9 10-3 mol/l at 25 °C,
which referred to the above reasons and also to the pres-
ence of –OCH3 group in the benzene nucleus which
decrease the repulsion extent. Interfacial tension (IT) val-
ues of the synthesized anionic Schiff bases were measured
between their aqueous solutions and benzene at 25 °C.
Table 3 shows higher interfacial tension (IT) values espe-
cially for SBVD (34.5 mN/m). Increasing the hydrophobic
chain length decreases the interfacial tension. The effi-
ciency values (PC20) of the targeted amphiphiles were
calculated using the data in Figs. 5 and 6, as the concen-
tration of the amphiphile solutions that decrease the surface
tension by 20 mN/m [28]. The PC20 values describe the
ability of these molecules to adsorb at the interface and
also indicate the accumulation extent of the surfactant
molecules at the interface. Increasing the hydrophobic
chain length of the studied amphiphiles results in a fast
decrease in the surface tension of the surfactant solution
indicating the high tendency of the longer hydrophobic
molecules to adsorb at the interface. The lowest PC20 value
was observed to SBSS and SBVS.
Synthesis
The Schiff base ligands IIIa-d; SBSD, SBSS, SBVD, and
SBVS were prepared by the condensation between 4-amino
alkyl benzene (IIa,b) with carboxymethyl or methoxyl car-
boxymethyl aldehyde (Ia,b) (1:1 M ratio) in ethanol. The
level of the purity of the ligands was checked by thin layer
chromatography on silica gel coated plates. All Schiff base
ligands were found to having similar structures, so the Schiff
base IIIa; SBSD was selected to study their complexation
properties and Ni–SBSD was synthesized. The mass spec-
trum of the complex [Ni(SBSD)2].2H2O, Fig. 3, the peak
observed at m/z 461.00 (3.97%) is evidence of the presence
of an organic ligand in the complex. The mass spectrum
shows the molecular ion peak at m/z 938 (calculated 940.01)
with an abundance of 3.78% confirmed the suggested for-
mula for the prepared complex, moreover, the spectrum
shows numerous peaks representing successive degradation
of complex molecules corresponding to various fragments,
their intensity gives an idea on the stability of the fragments.
Scheme 2 demonstrates the proposed paths of the decom-
position steps of the nickel-SBSD complex.
Thermogravimetric Study
The thermogravimetric study for [Ni(SBSD)2].2H2O
complex was carried out within the temperature range from
room temperature up to 1,000 °C. The determined tem-
perature ranges and percent losses in mass of the solid
complex on heating are given in Table 2. The results
obtained are in good agreement with the theoretical for-
mula suggested from the elemental analysis. Figure 4
shows the thermal analysis for the complex under study
and reveals the following findings:
The complex under study gives three-stage decomposi-
tion pattern. The first stage (28–122 °C) with an experi-
mental mass loss of 11.25% (theoretical 11.08%)
represents the loss of two molecules of H2O (hydrated),
one molecule of CH4 and two molecules of CH:CH. The
second stage within the temperature range 122–380 °C
represents the loss of two molecules of CH : CH and two
molecules of C6H5–C6H5. The experimental mass loss of
this step is 38.45% (theoretical 38.35%). The third stage at
temperature range 380–675 °C. may be attributed to the
loss of CH3(CH2)19CH3 and the experimental mass loss is
The maximum surface excess concentration Cmax was
calculated from the relationship [29]:
Cmax ¼ ꢁ1=RTðoc=olncÞcmc
where (qc/qlnc)cmc is the maximum slope of the plot c
versus log c at CMC at temperature T = 298 K and
R = 8.314 mol-1K-1. The Cmax values are directly used to
calculate the minimum surface area occupied by the
123

428
J Surfact Deterg (2010) 13:423–431
Scheme 2 Proposed
fragmentation route of
[Ni(SBSD)2]ꢀ2H2O complex
O
H
C
N
CH2
CH3-(CH2)11
C=O
Ni
O
N
O
.2H2O
(CH2)11-CH3
O
C
C
H2
CH
O
[Ni(SBSD) ].2H
O
2
2
940.01(938.00 ; 3.78%)
2H O/O /6CH
2
2
2
-2H O, L
2
O
H
C
N
CH2
O
CH3-(CH2)11
C=O
HC
N
CH2
Ni
O
CH3-(CH2)8
C=O
Ni
O
N
481.33 (483.00 ; 5.67%)
O
(CH2)8-CH3
O
C
11CH
2
CH
C
H2
O
H
C
N
CH2
787.79 (786.0 ; 11.21%)
CH3
C=O
C
H (CH )
4 2 5
Ni
6
O
327.00 (326.00 ; 13.33%)
CO
O
HC
N
CH2
CH3-(CH2)8
C=O
Ni
O
N
O
O
H
C
N
CH2
O
(CH2)3-CH3
O
C
C
CH3
CH
Ni
H2
298.99 (298.00 ; 22.38%)
O
641.54 (641.00 ; 8.75%)
10CH
2
CH2
O
H
C
N
CH3COO,CO
CH3
Ni
O
HC
N
CH2
282.99 (281.00 ; 7.78%)
HCN
CH3
C=O
Ni
O
N
O
(CH2)-CH3
O
C
CH
H
2C
2CH
CH2
O
2
O
H3C
Ni
501.24 (500.00 ; 16.58%)
Ni
255.96 (255.00; 11.68%)
227.90 (227.00 ; 34.57%)
C6H4CNCH2CH3
NiO
Ni
O
74.69(73.00 ; 52.43%)
HC
N
CH2
C=O
58.69 (57.00 ; 100.00%)
CH3
Ni
O
H3COCO
370.05 (370.00 ; 15.14%)
anionic Schiff base amphiphiles at the interface Amin
according to the equation:
where NAv is the Avogadro number. Increasing the maxi-
mum surface excess values indicates the increasing of
adsorbed molecules at the interface, hence the area avail-
able for each molecule will decrease. This causes the
1016
Amin
¼
NAvCmax
123

J Surfact Deterg (2010) 13:423–431
429
Table 2 Thermoanalytical results of [Ni(SBSD)2]ꢀ2H2O complex
Complex compound
Stage
Temp. range
(°C)
Mass loss%
Calculated
Evolved moiety
Found
[NiC54H72N2O6].2H2O
I
28–122
122–380
380–675
11.08
38.35
31.56
11.25
38.45
31.70
2 H2O (hydrated), CH4 and 2 CH : CH
2 CH : CH and 2 C6H5–C6H5
CH3(CH2)19CH3
II
III
Fig. 6 Variation of the surface tension with the surfactant concen-
tration for IIIc,d
Fig. 4 TG thermogram for metal complex, [Ni-(SBSD)2]ꢀ2H2O
complex
solution interface and Amin is the minimum surface area of
the surfactant as shown in Table 3. It is clear from Table 3
that Iact. decreased by increasing the alkyl chain and the
high depression were observed for SBSS.
Thermodynamic of Adsorption and Micellization
The micellization and adsorption processes of the amphi-
phile molecules occurred instantly, but commonly one
process may be predominate over the other. The predom-
inance of any of the two processes is governed by the
thermodynamic variables of this process.
Fig. 5 Variation of the surface tension with the surfactant concen-
tration for IIIa,b
From Table 3 values of DGmic and DGads are always
negative indicating these two processes are spontaneous;
however, there is a slight increase in the negative values of
DGads compared to those of micellization. This suggests
the tendency of the molecules to be micellized at the
interface and the presence of these amphiphiles at the
interface to decrease the phases interaction.
compacting of surfactant molecules at the interface to form
a denser layer (Table 3).
The difference between the surface tension of the pre-
pared compounds at their CMC and that of the pure water
is called their effectiveness (pcmc):
pcmc ¼ co ꢁ ccmc
where co is the surface tension of pure water and ccmc is the
surface tension of the surfactant solution at CMC. The most
efficient one results in the greatest lowering in surface
tension at critical micelle concentration. SBSD and SBVD
were found to be the most efficient compounds, giving the
largest reduction in surface tension at CMC because they
achieved a lower surface tension at CMC, Table 3.
Biological Activity
Table 4 shows the antibacterial activity of the prepared
anionic Schiff bases (IIIa–d), nickel SBSD complex and
NiCl2.6H2O. Chloramphenicol and cephalothin were taken
as the reference drugs for antibacterial activity. The dif-
ference in activity depends on the length of hydrophobic
chains and the interfacial properties of the prepared sur-
factants. Increasing the hydrophobic chain length increase
the antibacterial activity, these results are in consistence
The interfacial activity (Iactiv) which expressed physi-
cochemical parameter DGads/Amin where DGads is a stan-
dard free energy of adsorption of the surfactant at the air/
123

430
J Surfact Deterg (2010) 13:423–431
Table 3 Surface parameters of the synthesized anionic Schiff base amphiphiles
Surfactant
IT
mN/m
CMC
10-3 mol/L
pcmc
mN/m
C20 9 10-3
mmol/L
PC20
mmol/L
Amin nm2
DGmic
kcal/mol
DGads
kal/mol
I 9 102
activity
SBSD
SBSS
SBVD
SBVS
33.0
30.5
34.5
31.5
5.01
3.16
39.0
34.5
37.5
33.5
2.82
4.47
2.51
3.16
2.55
2.35
2.60
2.50
205.32
155.29
164.68
143.72
-14.87
-16.01
-12.87
-14.58
-15.35
-16.33
-13.24
-14.87
-7.48
-10.52
-8.04
11.22
5.62
-10.35
DGmic = [2.303 RT log CMC]-[log 55.5], DGads = DGmic-(0.6023 10-2) Pcmc Amin
Table 4 Biological activity of the synthesized Schiff bases and [Ni–(SBSD)2]ꢀ2H2O complex
Compounds Tested microorganism
Staphylococcus aureus (G?) Streptococcus pyogenes (G?) Pseudomonas phaseolicola (G-) Pseudomonas fluorescens (G-)
Concentration 2
1
2
1
2
1
2
1
SBSD
5
3
7
3
10
16
16
22
14
32
36
7
8
4
SBSS
SBVD
SBVS
18
20
22
16
14
18
13
28
28
22
17
20
18
30
38
17
15
14
16
26
30
11
10
15
11
21
25
15
18
21
17
28
38
10
14
14
14
24
30
NiCl2ꢀ6H2O 15
Ni-SBSD
32
Control
42
Control Chloramphenicol was used as the standard for the Gram positive and cephalothin for the Gram negative bacteria
References
with the adsorption tendency of these amphiphiles at the
interface.
1. Mirkin MV, Bard AJ (1991) Voltammetric method for the
determination of borohydride concentration in alkaline aqueous
solutions. J Anal Chem 63:532–533
2. Marcell DL, Thatyana RA, Erika MD, Maria CS, Solange MS,
James LW, Vitor FF, Marcus VN (2009) Synthesis and antitu-
bercular activity of novel Schiff bases derived from D-Mannitol.
Carbohydr Res 12:2042–2047
The relationship between interfacial activity of the sur-
factants and their biological activity for some strains of
microorganisms was studied by Stephen and Donald [30];
in each case the interfacial activity is expressed by DGads
/
A
min, Tables 3, 4 and Figs. 5, 6 indicate that there is an
excellent linear relationship between interfacial activity
and biological activity. Also, Table 4 shows the antibac-
terial activity of the synthesized nickel–SBSD complex and
clear that the complexation of the Schiff bases by nickel
cation increases their antibacterial activity.
3. Zhu TL, Tang J, Chan MX (2000) Influence of ligand backbones
and counter ions on structures of helical silver (I) complexes with
di-Schiff bases derived from phthalaldehydes and diamine.
J Chem Soc Dalton Trans 22:4182–4186
4. Badawi AH, Mohamed MAS, Mohamed MZ, Khowdairy MM
(2007) Surface and antitumor activity of some novel metal-based
cationic surfactants. Assoc Radiat Oncologists India 3:198–206
5. Zhu WR, Hu PZ, Li MY, Huang XL, Wu CT (2003) Synthesis of
new Schiff bases containing thiophene moiety. J Nat Sci
8(2A):433–436
6. Li MY, Hu PZ, Zhu WR, Wang Y (2003) Synthesis and char-
acterization of open ring polycomponent complexes formed in
the reaction of lanthanide with m-phenylenediamine and diben-
zoyl methane. Asian J Chem 15:38–42
7. Nabel AN, Mohamed FZ (2008) Structural and biological
behaviors of some nonionic Schiff- base amphiphiles and their
Cu(II) and Fe(III) metal complexes. Colloid Surf B 64:179–183
8. Scheehan J, Grenda VI (1962) The N-(2-Hydroxyarylidene)
protecting group in peptide synthesis. J Am Chem Soc 84:2417–
2420
Metal chelates generally have higher antibacterial
activity than the free ligands due to an increase in cell
permeability [31]. The lipid membrane which surrounds
the cell, favors the passage of only lipid soluble materials
and it is known that liposolubility is an important factor
controlling antimicrobial activity. By complexation, the
ionic groups and the electron delocalization over the Schiff
base molecules participate in the complex molecules,
which in turn increases the hydrophobic character of the
metal chelate and raises the liposolubility thus favoring its
permeation through the lipid layer of a microorganism.
Therefore it confirms that chelation of the anionic Schiff
bases with a transition metal tends to make the ligands act
more powerfully against bacteria.
9. Raman N, Muthuraj V, Ravichandran S, Kulandaisamy A (2003)
Synthesis, characterisation and electrochemical behaviour of
Cu(II), Co(II), Ni(II) and Zn(II) complexes derived from
123

J Surfact Deterg (2010) 13:423–431
431
acetylacetone and p-anisidine and their antimicrobial activity.
J Chem Sci 115:161–167
10. Ismail AA, Negm NA (2009) Some Schiff base surfactants as
steel-corrosion inhibitors. J Surf Deterg 12:313–319
11. Zhangyi L, Chuanzhong W, Jianbin H (2003) The research on the
vesicle formation and transformation in novel gemini surfactant
systems. Colloids Surf A 224:213–220
12. Wen-long L, Yang, Chun-Lin N, Zhao-Ping N, Zhi YL, Yuan-
Gen Y, Qing-Jin M (2003) Synthesis and characterization of
copper(II) Schiff base complexes derived from salicylaldehyde
and glycylglycylglycine. Polyhydron 23:849–855
22. Lijuan H, Zhongbin Y, Hong C, Pingya L (2009) The interfacial
tension between cationic gemini surfactant solution and crude oil.
J Surfact Deterg 12:185–190
23. Kiehlbauch JA, Hannett GE, Salfinger M, Archinal W, Monserrai
C, Clin J (2000) Use of the national committee for clinical lab-
oratory standards guidelines for disk diffusion susceptibility
testing in New York state laboratories. Microbiol 38:3341s–
3348s
24. Negm NA, Hafiz AA, El-Awady MY (2004) Influence of struc-
ture on the cationic polytriethanol ammonium bromide deriva-
tives. I. Synthesis, surface and thermodynamic properties. Egypt J
Chem 47:369–382
25. Negm NA, Mahmoud SA (2005) Corrosion inhibition efficiency
of nonionic Schiff base amphiphiles of p-aminobenzoic acid for
aluminum in 4 N-HCl. Egypt J Petrol 14:79–87
13. Hanna SA, Salam JJ, Rajendra P, Shri C (2005) Synthesis,
characterization and study of polymeric iron (III) complexes with
bidentate P-hydroxy Schiff bases as heterogeneous catalysts.
J Mol Catal A Chem 225:225–232
14. Abdel-Latif SA, Hassib HB, Issa YM (2007) Studies on some
salicylaldehyde Schiff base derivatives and their complexes with
Cr(III), Mn(II), Fe(III), Ni(II) and Cu(II). Spectrochimica Acta
Part A 67:950–957
15. Abou El-Enein SA, El-Saied FA, Kasher TI, El-Wardany AH
(2007) Synthesis and characterization of iron(III), manganese
(II), cobalt(II), nickel(II), copper(II) and zinc(II) complexes of
salicylidene-N-anilinoacetohydrazone (H2L1) and 2-hydroxy-1-
naphthylidene-N-anilinoacetohydrazone (H2L2). Spectrochimica
Acta Part A 67:737–743
16. Scozzafava A, Menabuoni T, Mincione F (2001) Carbonic
anhydrase inhibitors: synthesis of sulfonamides incorporating
dtpa tails and of their zinc complexes with powerful topical an-
tiglaucoma properties. Bioorg Med Letter 11:575–582
17. Scozzafava A, Supuran CT (2000) Sulfonamide derivative as
amatrix metalloproteinase inhibitor. J Med Chem 43:3677–3687
18. Supuran CT, Scozzafava A (2000) Carbonic anhydrase inhibitors
part 98. 1, 3, 4-thiadiazole-2-sulfonamide derivatives as antitu-
mor agents. Eur J Med Chem 35:867–874
19. Chohan ZH, Perrvez H, Kausar S (2002) Synthesis and charac-
terization of antibacterial Co(II), Cu(II), Ni(II), and Zn(II) com-
plexes of acylhydrazine derived pyrrolyl compounds. Synth
React Inorg Met Org Chem 32:529–543
26. Rosen MJ (1989) Surface and interfacial phenomena, 2nd edn.
Wiley, New York, p 151
27. Nabel AN, Mohamed FZ, Mounir AIS (2009) Synthesis and
evaluation of 4-diethyl amino benzaldehyde Schiff base cationic
amphiphiles as corrosion inhibitors for carbon steel in different
acidic media. J Surf Deterg 12:321–329
28. Taiga T, Wanbin Z, Yohjin N, Kazuhiro M, Kenji M, Misa T,
Taro F, Isao I (2001) Preparation, surface-active properties, and
antimicrobial activities of bis(alkylammonium) dichlorides hav-
ing a butenylene or a butynylene spacer. J Surf Deterg 4:271–277
29. Dianno D, Talmon Y, Zana R (1995) Alkanediyl-alpha-omega-
bis (dimethyl alkylammonium bromide) surfactants (dimeric
surfactants). Aggregation and microstructure in aqueous solu-
tions. Langmuir 11:1448–1456
30. Stephen WM, Donald JV (2001) The relationship between the
interfacial properties of surfactants and their toxicity to aquatic
organisms. Environ Sci Technol 35:954–959
31. Farekh J, Inamdhar F, Nair R, Baluja S, Chanda S (2005) Syn-
thesis and antibacterial activity of some Schiff bases derived from
4-aminobenzoic acid. J Serb Chem 76:1155–1161
Author Biography
20. Espin I (2009) The synthesis, characterization, electrochemical
character, catalytic and antimicrobial activity of novel, azo-con-
taining Schiff bases and their metal complexes. Dyes Pigments
82:13–19
21. Bassett J, Denney RC, Jeffery GH, Mendham J (1987) Vogel’s
text book of quantitative inorganic analysis including elementary
instrumental analysis, 4th edn. Longman Scientific and Technical,
England
Fatma H. Abdel-Salam received her B.Sc. with Honors in Chemistry
(1983) and her M.Sc. (1989) and Ph.D. (1994) in Applied Organic
Chemistry, from the Faculty of Science, Al-Azhar University, Cairo,
Egypt. She is interested in the synthesis of surfactants, the surface
and thermodynamic properties of surfactant solutions and their
applications.
123