Preliminary in vitro cytotoxic assay on HepG2 and antibacterial screening activity: Synthesis and characterization of organotin(IV) complexes derivatives of 2-methyl-3-nitrobenzoic acid

Article abstract of DOI:10.14233/ajchem.2013.13783

Three organotin(IV) carboxylate complexes derivatives of 2-methyl-3-nitrobenzoic acid (HL) have been successfully synthesized and characterized quantitatively and qualitatively. The complexes obtained are screened for their preliminary in vitro cytotoxic

Full text of DOI:10.14233/ajchem.2013.13783

Asian Journal of Chemistry; Vol. 25, No. 6 (2013), 3376-3380
http://dx.doi.org/10.14233/ajchem.2013.13783
Preliminary in vitro Cytotoxic Assay on HepG2 and Antibacterial Screening Activity: Synthesis
and Characterization of Organotin(IV) Complexes Derivatives of 2-Methyl-3-nitrobenzoic Acid
2,*
1
3
4
YIP-FOO WIN1,2*, SIANG-GUAN TEOH , SIE-TIONG HA , TENGKU-SIFZIZUL TENGKU-MUHAMMAD and EMAD YOUSIF
1Department of Chemical Science, Faculty of Science, Universiti TunkuAbdul Rahman, Perak Campus, Jalan Universiti, Bandar Barat, 31900
Kampar, Perak, Malaysia
2School of Chemical Sciences, Universiti Sains Malaysia, 11800 Minden Penang, Pulau Pinang, Malaysia
3Department of Biological Sciences, Universiti Malaysia Terengganu, 21030 Kuala Terengganu, Malaysia
4Department of Chemistry, College of Science, Al-Nahrain University, Baghdad, Iraq
*Corresponding author: Fax: +60 5 4661676; Tel: +60 5 4688888; E-mail: williamyfw@yahoo.com
(Received: 24 March 2012;
Accepted: 21 December 2012)
AJC-12591
Three organotin(IV) carboxylate complexes derivatives of 2-methyl-3-nitrobenzoic acid (HL) have been successfully synthesized and
characterized quantitatively and qualitatively. The complexes obtained are screened for their preliminary in vitro cytotoxic assay on
human liver hepatocellular carcinoma cells (HepG2) and antibacterial screening activity. Results of the infrared and NMR spectroscopy
on the acid and complexes showed that the coordination took place via oxygen atoms from the carboxylate anions. With the exceptional
case, based on the spectroscopy studies indicated that one methanol molecule also take part in the coordination to tin(IV) atom moiety in
complex 3 resulting the tin(IV) atom exhibited five coordination in solid state. From the preliminary in vitro cytotoxic assay on HepG2
and antibacterial screening activity, triphenyltin(IV) (complex 3) showed slightly better activity compared to diorganotin(IV) complexes
(1 and 2).
Key Words: Organotin(IV) complexes, In vitro cytotoxic assay, Antibacterial activity.
purification. The infrared spectra were recorded using a Perkin-
Elmer System 2000 FTIR Spectrophotometer as a KBr disc in
the frequency range of 4000-400 cm-1. The spectra for 1H and
119Sn NMR were recorded on a Bruker AC-P 400 MHz FT
NMR spectrometer and 13C NMR was recorded on a Bruker
AC-P 300 MHz FT NMR spectrometer using deuterated CDCl3
and d6-DMSO as the solvent and tetramethylsilane, TMS as
the internal standard. Elemental C, H and N analyses were
carried out on a Perkin-Elmer 2400 CHN elemental analyzer.
Tin was determined gravimetrically by igniting a known quantity
of each complex to SnO2. The melting points were determined
in an open capillary and were uncorrected.
INTRODUCTION
In general, the coordination chemistry of organotin(IV)
complexes are extensively studied due to its coordination
geometries as well as structural diversity (monomer, dimeric,
hexameric and oligomeric)1-5. It was also well-documented that
the participation of coordinating solvent molecules to tin(IV)
atoms moieties and its coordination sphere will influence the
overall structural of organotin(IV) complexes3,4,6. And up-to-
date, numerous studies on organotin(IV) complexes have been
carried out in order to study its biological properties against
bacterial, fungal and cancer cells line to explore its structural-
activity relationship7-14
.
Preparation of dimethyltin(IV) oxide, Me2SnO:
Dimethyltin(IV) dichloride was dissolved in distilled water
and stirred for 16 h. Colourless solution was obtained. Ammonia
solution (60 %) was added into the colourless solution and
finally white precipitate was obtained. The precipitate was
placed in an oven (60 ºC) for a few days to dry.
In this paper, we report on the synthesis and structural
characterization of new organotin(IV) carboxylate complexes
derived from 2-methyl-3-nitrobenzoic acid (HL). Moreover,
the preliminary in vitro cytotoxic assay on human liver hepato-
cellular carcinoma cells (HepG2) and antibacterial screening
activity of the complexes obtained were carried out and the
results were reported herein.
Preparation of sodium salt: The sodium salt of the acid
was obtained by heating under reflux a 1:1 molar mixture of
sodium hydroxide, NaOH and 2-methyl-3-nitrobenzoic acid
in ethanol (50 mL) for 2 h. After a few days, white precipitates
were obtained as sodium salt of 2-methyl-3-nitrobenzoic acid:
EXPERIMENTAL
All the reagents, starting materials as well as the solvents
were purchased commercially and used without any further

Vol. 25, No. 6 (2013)
Synthesis and Characterization of Organotin(IV) Complexes Derivatives 3377
FTIR as KBr disc (cm-1) selected data: ν(COO)as 1629,
ν(COO)s 1358.
1H); 7.72 (dd, 1.4 Hz, 8.1 Hz, 1H); 8.23 (dd, 1.3 Hz, 7.8 Hz,
1H); methyl, CH3 2.61 (s, 3H); CH3OH 3.35 (s, 3H). 13C NMR
(ppm) (CDCl3): δ: phenyl carbons Cipso 138.52 (591.1 Hz),
Cortho 137.44 (48.4 Hz), Cmeta 129.92 (64.5 Hz), Cpara 130.99
(13.2 Hz); benzene 126.74, 126.91, 130.70, 133.63, 135.08,
151.58; CH3 17.09; CH3OH 51.20; COO 173.19. 119Sn NMR
(ppm) (CDCl3): δ: -106.02.
Synthesis of organotin(IV) complexes
Preparation of (2-CH3-3-NO2-C6H3COO)2(CH3)2Sn
(1): Complex 1 was obtained by heating under reflux a 1:2
molar mixture of dimethyltin(IV) oxide (0.33 g, 2 mmol) and
2-methyl-3-nitrobenzoic acid (0.73 g, 4 mmol) in acetone
(50 mL) for 3 h. A clear colourless transparent solution was
separated by filtration and kept in a bottle. After few days,
yellow solids (0.67 g, 65.2 % yield) were collected. m.p. 223.4-
224.1 ºC. Analysis for C18H18N2O8Sn: C, 42.62; H, 3.10; N,
5.45; Sn, 22.66 %. Calcd. for C18H18N2O8Sn: C, 42.47; H, 3.56;
N, 5.50; Sn, 23.33 %. FTIR as KBr disc (cm-1): ν(C-H)
aromatic 3089, ν(C-H) saturated 2993, 2948, 2864; ν(COO)as
1618; ν(COO)s 1348; ν(NO2) 1526, ν(O-Sn-O) 613, ν(Sn-C)
2-Methyl-3-nitrobenzoic acid (HL): The parent acid,
2-methyl-3-nitrobenzoic acid (HL) was purchased from acros
organics and used without any further purification. FTIR as
KBr disc (cm-1): Selected data: ν(OH) 2887-2552, ν(COO)as
1
1699, ν(COO)s 1368. H NMR (ppm) (CDCl3): δ: benzene
protons 7.47 (t, 8.0 Hz, 1H); 7.93 (dd, 1.2 Hz, 8.1 Hz, 1H);
8.23 (dd, 1.2 Hz, 7.9 Hz, 1H); methyl 2.74 (s, 3H). 13C NMR
(ppm) (CDCl3): δ: benzene carbons 126.25, 127.14, 131.06,
133.29, 134.52, 151.58; methyl 15.61; COO 167.83.
1
584, ν(Sn-O) 489. H NMR (ppm) (d6-DMSO): δ: benzene
Preliminary in vitro cytotoxic assay: The in vitro cytoto-
xic assay was carried out against human liver hepatocellular
carcinoma cells line, HepG2. The cells were maintained in
Eagle's minimum essential medium supplemented with 2 mM
of L-glutamine, 1 mM of sodium pyruvate, 0.1 mM of non-
essential amino acid, 1.5 µg/mL sodium bicarbonate, 100 IU/
mL penicillin and 100 µg/mL streptomycin. The cytotoxicity
assay was determined using the microtitration 3-(4,5-dimethyl-
protons 7.46 (t, 7.9 Hz, 2H); 7.86 (d, 3.7 Hz, 2H); 7.89 (s,
2H); CH3 2.49 (s, 6H); methyl, CH3 0.95 (s, 6H), 2J(119Sn-1H)
= 102.17 Hz. 13C NMR (ppm) (d6-DMSO): δ: benzene carbons
125.97, 127.73, 130.83, 133.66, 138.34, 152.14; CH3 16.43;
methyl 12.24, 1J (119Sn-13C) = 908.6 Hz; COO 172.16. 119Sn-
NMR (ppm) (d6-DMSO): δ: -261.95.
Preparation of [{2-CH3-3-NO2-C6H3COO(C4H9)2Sn}2
O]2 (2): Complex 2 was obtained by heating under reflux a
1:2 molar mixture of dibutyltin(IV) oxide (0.75 g, 3 mmol)
and 2-methyl-3-nitrobenzoic acid (1.10 g, 6 mmol). The
reaction was carried out in a mixture of ethanol/hexane (3:2,
50 mL) for 3 h.A clear yellow transparent solution was isolated
by filtration and kept in a bottle.After few days, yellow crystals
(0.91 g, 72.0 % yield) were collected. m.p. 138.1-138.7 ºC.
Analysis for C64H96N4O18Sn4: C, 45.73; H, 5.63; N, 3.32; Sn,
16.76 %. Calcd. for C64H96N4O18Sn4: C, 45.64; H, 5.75; N,
3.33; Sn, 17.09 %. FTIR as KBr disc (cm-1): ν(C-H) aromatic
3079, ν(C-H) saturated 2955, 2929, 2869; ν(COO)as 1629,
1531; ν(COO)s 1341, 1405; ν(NO2) 1561, ν(Sn-O-Sn) 625,
ν(Sn-C) 577, ν(Sn-O) 482. 1H NMR (ppm) (CDCl3): δ: ben-
zene protons 7.40 (t, 7.8 Hz, 4H); 7.85 (d, 7.9 Hz, 4H); 8.17
(s, 4H); methyl, CH3 2.71 (s, 12H); butyl, CH3 0.83-0.96 (m,
24H), 1.27-1.49 (m, 16H); CH2 1.52-1.65 (m, 16H); CH2 1.72-
1.87 (m, 16H). 13C NMR (ppm) (CDCl3): δ: benzene carbons
126.25, 127.22, 131.82, 133.68, 134.98, 152.46; CH3 16.68;
butyl 13.95, 26.07, 26.32, 27.82, 28.03, 28.93, 30.30; COO
176.26, 173.79. 119Sn-NMR (ppm) (CDCl3): δ: -143.15,
-207.94.
thiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay15,16
.
The assay of each concentration for each compound was
performed in triplicate. The fraction of surviving cells was
measured relative to the untreated cell population by measuring
the absorbance values at 570 nm with a reference at 630 nm
using an ELISA microplate reader (Bio Tek EL 340, USA)15.
Cytotoxicity was expressed as fifty percent cytotoxic dose
(IC50), i.e. the concentration causing 50 % inhibition of cell
growth with reference to the control (untreated cells). The IC50
and the S.E.M. (standard error of the mean) was determined
using Probit Analysis (SPSS, version 12.0.1).
Preliminary in vitro antibacterial screening activity:
The synthesized organotin(IV) complexes and acid (HL) were
screened for their in vitro antibacterial activity against three
gram-negative (Escherichia coli, Pseudomonas aeruginosa and
Klebsiella pneumoniae) and two gram-positive (Bacillus
subtilis and Staphylococcus aureus) bacterial strains, by inhibi-
tion zone method using agar well diffusion method. The seeded
agar (nutrient agar medium) was prepared by cooling the
molten agar to 40 ºC and then adding bacterial inoculums
containing approximately 104-106 colony forming units (CFU)/
mL. The bacterial inoculums were spread on the plate
containing agar medium and even coverage was ensured before
the agar solidified. The complexes were dissolved in DMSO
to prepare 1.0 mg/mL concentration. By using a sterile metallic
borer, the wells (6 mm in diameter) were dug and the standard
drugs and complexes were introduced into the respective wells.
The plates were incubated immediately at 37 ºC for 20-24 h.
The activity was determined by measuring the diameter of the
inhibition zone (in mm).
Preparation of 2-CH3-3-NO2-C6H3COO(C6H5)3Sn
.CH3OH (3): The title complex was obtained by heating
under reflux a 1:1 molar mixture of triphenyltin(IV) hydroxide
(0.73 g, 2 mmol) and 2-methyl-3-nitrobenzoic acid (0.36 g,
2 mmol) in methanol (50 mL) for 1 h. A clear yellow trans-
parent solution was isolated by filtration and kept in a bottle.
After few days, yellow crystals (0.87 g, 77.7 % yield) were
collected. m.p. 121.3-121.9 ºC. Analysis for C27H25N1O5Sn:
C, 57.53; H, 4.04; N, 2.45; Sn, 21.02 %. Calcd. for
C27H25N1O5Sn: C, 57.68; H, 4.48; N, 2.49; Sn, 21.11 %. FTIR
as KBr disc (cm-1): ν(C-H) aromatic 3065, 3022; ν(C-H)
saturated 2922, ν(COO)as 1608, ν(COO)s 1345, ν(NO2) 1520,
ν(Sn-O) 450. 1H NMR (ppm) (CDCl3): δ: phenyl protons 7.43-
7.50 (m, 9H); 7.78-7.82 (m, 6H); benzene 7.27 (t, 7.9 Hz,
RESULTS AND DISCUSSION
In this study, complexes 1-3 have been obtained in solid
state. The micro-elemental analysis for C, H, N and Sn data

3378 Win et al.
Asian J. Chem.
Me
Sn
O
O
O
O
+ H2O
C
C
HOOC
Me2SnO
+
2
Me
H3C
NO2
CH3
NO2
O2N
O2N
H3C
1
Bu Bu
Sn
CH3
H3C
NO2
C
O
O
C
O
O
O
O
Bu
Bu
Bu
Bu
Sn
Sn
+ 2H2O
HOOC
Bu SnO
2
+
4
4
NO2
H3C
O
C
O
C
Sn
O
O
H3C
NO2
CH3
O2N
Bu
Bu
2
Ph
O
O
methanol
Ph Sn
HOOC
+
C
+ H2O
Ph3SnOH
Ph
NO2
H3C
NO2
H3C
CH3OH
Me= methyl, Bu= butyl & Ph= phenyl
3
Fig. 1. Proposed structure for complexes 1-3
obtained were in agreement with the predicted formula for
complexes 1-3. Based on the elemental analysis, it is believed
that a methanol molecule was present in complex 3 which
might be have been trapped or acted as a solvate in those
reported similar complexes3,4,6. This phenomenon has been
clarified and the X-ray crystal structure of complex 3 has been
reported6. Complexes 1-3 gave a sharp melting point indicated
the isolation of fairly pure complexes. An outline of the
proposed structure for complexes 1-3 are depicted in Fig. 1.
The ν(O-H) bands for the acid, HL was absent in the
infrared spectra of salt and complexes 1-3 showed the
deprotonation and coordination of the carboxylate anion. In
addition, complexes 1-3 revealed that the ν(COO)as was shifted
to a lower wavelength number compared to the acid (HL)
which signified that the coordination took place via the oxygen
atoms of the carboxylate anion. Complex 1 was isolated as a
monomeric type and its ∆ν was 270 cm-1, which was compa-
rable to the sodium salt (∆ν = 271 cm-1) of 2-methyl-3-
nitrobenzoic acid, indicating that the carboxylate anions were
coordinated to the tin(IV) atom moiety in a bidentate manner17.
From the infrared spectra of complex 2, two ∆ν values (288
and 126 cm-1) were observed and both values were either
comparable or lower than the ∆ν of the sodium salt indicating
that all the carboxylate anions were bonded to the tin(IV)
atoms in a bidentate mode17. As a result, two tin(IV) atoms
exhibited a distorted trigonal bipyramidal geometry and while
another two tin(IV) atoms exhibited a distorted octahedral
geometry in complex 2. For complexes derived from
triphenyltin(IV) carboxylate, ∆ν greater than 200 cm-1 would
be expected for the monodentate bonding carboxylate anions18.
Hence, the carboxylate anion in complex 3 would be expected
to bond to the tin(IV) atom in monodentate manner since
the ∆ν above 250 cm-1. Based on the elemental analysis, a
methanol molecule was present in complex 3. As a result the
absorption bands of the aliphatic and aromatic functional
groups centered around 3000 cm-1 appeared as though they
were sitting on a small hump together with the ν(OH) band in
the spectra of complexes 3. Hence, the tin(IV) atom of complex
3 was five-coordinated and exhibited a trigonal bipyramidal
geometry. For further information and structural clarity, the
structure of complex 3 has been reported by our research
group6. The infrared spectrum of complex 3 is depicted in Fig. 2
as a representative.
1
The H NMR spectra of complexes 1-3 exhibited simi-
larities to their acid, HL. In the upfield regions of the 1H NMR
spectra of the complexes 1 and 2 showed the signal of the

Vol. 25, No. 6 (2013)
Synthesis and Characterization of Organotin(IV) Complexes Derivatives 3379
methyl and butyl protons of the organotin(IV) at 0.95 ppm
and in the range of 0.83-1.87 ppm respectively. For complex
3, the resonances appeared as two well separated sets of multi-
plets in the regions centering around δ ≈ 7.48 and 7.80 ppm
(downfield) with integration values of 9:6 respectively, ascribed
to the aromatic protons of the phenyl group19. Based on the 1H
NMR spectral studies of complex 3, the proton resonances
originating from the methanol molecule occurred at δ = 3.35
ppm; based on the integration, only one methanol molecule
was present in complex 3.
ppm indicating that the tin(IV) atom was remained six-
coordinated and exhibited a distorted octahedral geometry.
Complex 3 showed that the δ(119Sn) value at -106.02 ppm,
which lie in the range of -40 to -120 ppm [for triphenyltin(IV)
complexes], hence, indicating that the tin(IV) atom in
complex 3 was four-coordinated with a distorted tetrahedral
geometry21,22. From the 119Sn NMR spectral studies, it is
believed that methanol molecule was disassociated upon
dilution during the NMR solution preparation resultant tin(IV)
atom in complex 3 became four-coordinated.
Preliminary in vitro cytotoxic assay and antibacterial
screening activity: The preliminary in vitro cytotoxic assay
of acid (HL) and its organotin(IV) complexes 1-3 are given in
Table-1. Based on the data given in Table-1, it was found that
both the acid and complex 1 were inactive against HepG2 cell
lines. In addition, complex 3 (0.143 µg/mL) was more active
compared to complex 2 (0.171 µg/mL). This is due to complex
2 were obtained as organodistannoxane dimer type (bulky
molecules) hence the aid of ligands on organotin(IV) to the
receptor (active) sites of the cells was inhibited. In general,
complex 3 was derivatives of triorganotin(IV), which is more
active compared to the diorganotin(IV)25-27. In addition, in
solution form, complex 3 was four-coordinated and exhibited
distorted tetrahedral geometry (sp3) causing them to be more
active20. However, their activities were lower compared to the
vincristine sulphate (reference drug).
75.2
70
1736
2257
1822
919
524
1957
1890
855
476
419
60
50
40
30
20
10
1116
839
778
1201
798
580
1262
1228
893
997
814
3542
663
1145
2992
3022
1306
1291
1080
1018
1482
1467
3065
1568
450
1430
1520
1345
1376
1608
730
696
0
PH3SN2M3NB
-5.0
4000.0
3000
2000
1500
1000
400.0
–1
cm
Fig. 2. Infrared spectrum of complex 3
Evidence of the formation of the complexes is displayed
in the 13C NMR spectra. The 13C NMR spectra of complexes
1-3 showed the δ(COO) signal shifted to the downfield region
which is lower compared to that of the acid, HL indicating the
carboxylate anion is bonded to tin(IV) atom. Complex 1
exhibited a sharp signal at 12.24 ppm indicating the presence
of the methyl groups in the SnMe2 moiety whereas complex 2
was derivatives of organodistannoxane dimer types exhibited
two sets of signals corresponding to the butyl groups in the
13C NMR spectra. These two sets of signals were attributed to
the butyl groups linked to the exo- and endo-cyclic tin(IV)
atom respectively20. Complex 3 revealed the chemical shifts
of the δ(13C)ipso at 138.52 ppm respectively indicative of a four-
coordinated tin(IV) atom21-23. Complex 3 also showed that the
1J(119Sn-13C) value of 591.1 Hz lie in the range of 550-660 Hz,
thus indicating that the tin(IV) atom in complex 3 was four-
coordinated and has a distorted tetrahedral geometry. In addi-
tion, in the 13C NMR spectra of complex 3, the signals due to
the methanol molecule was located at the upfield region at δ =
51.20 ppm as observed.
The δ(119Sn) value of the four-coordinated complexes fall
in the range between +200 to -60 ppm; the five-coordinated
complexes between -90 to -190 ppm and the six-coordinated
complexes between -210 to -400 ppm24. Complexes derivatives
of organodistannoxane dimer types usually exhibit two well
resolved δ(119Sn) signals (complex 2 = -143.15, -207.94 ppm).
These two low- and high-field resonances were attributed to
the exo- and endo-cyclic tin(IV) atoms14,20. Based on the 119Sn
NMR spectra, all the tin(IV) atoms in complex 2 were five-
coordinated and each exhibited a distorted trigonal bipyramidal
geometry. This maybe due to the disassociation of the bidentate
bonds upon dilution during the preparation of the NMR sample
in solution form. The δ(119Sn) value of complex 1 was -261.95
TABLE-1
PRELIMINARY CYTOTOXIC ASSAYS, IC50 VALUE OF
ACID (HL) AND ITS ORGANOTIN(IV) COMPLEXES 1-3
IC50 (µg/mL)
Complexes
Human liver hepatocellular
carcinoma cells, HepG2
HL
1
Inactive (start at 1.0)
Inactive (start at 1.0)
0.171 0.011
2
0.143 0.013
3
Vincristine sulphate (reference)
0.042 0.031
IC50 (µg/mL) = concentration that yields 50 % inhibition of the cell
compared with untreated control; The cytotoxicity values are
expressed as mean S.E.M. from the triplicate
The preliminary in vitro antibacterial screening activity
of acid (HL) and its organotin(IV) complexes 1-3 are given in
Table-2. Inhibition zones with a diameter less than 10 mm are
considered as weak; larger than 10 mm but less than 16 mm
are considered as moderate and finally larger than 16 mm and
above are active13,28. Based on this study, complex 3 which
was derivatives of triphenyltin(IV) were found to be more
active compared to the diorganotin(IV) complexes (1 and 2)
and acid (HL) against Bacillus subtilis, Pseudomonas aeruginosa
and Staphylococcus aureus but lower compared to the reference
drugs. Based on the structural-activity study, complex 3 was
found to be more active due to complex 3 was obtained as a
simple monomer, four-coordinated and exhibited tetrahedral
(sp3) in solution form whereas complexes 1 (distorted octa-
hedral) and 3 (bulky molecule) obtained as a more complicated
structure which in turn restrict their mobility to the target cell
or active site. Moreover, based on the data in Table-2 showed
that complex 3 was completely inactive against Klebsiella

3380 Win et al.
Asian J. Chem.
TABLE-2
PRELIMINARY IN VITRO ANTIBACTERIAL SCREENING ACTIVITY OF ACID (HL) AND ITS ORGANOTIN(IV) COMPLEXES 1-3
Inhibition zone (mm)
Complexes
Bacillus subtilis
Escherichia coli
Klebsiella pneumoniae
Pseudomonas aeruginosa Staphylococcus aureus
HL
12
14
11
16
29
34
25
9
10
10
8
13
11
11
-
12
14
9
12
14
11
17
30
28
37
1
2
23
34
40
29
3
Chloramphenicol
Doxycycline
Rifampicin
-
23
21
23
24
24
Agar well diffusion method (in vitro) = 1.0 mg/mL; Reference drug = chloramphemicol, doxycycline and rifampicin
8. R. Willem, A. Bouhdid, B. Mahieu, L. Ghys, M. Biesmans, E.R.T.
Tiekink, D. de Vos and M. Gielen, J. Organomet. Chem., 531, 151
(1997).
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complex 3 was selective against certain bacterial starins.
9. S.G. Teoh, S.H. Ang, S.B. Teo, H.K. Fun, K.L. Khew and C.W. Ong, J.
Chem. Soc., Dalton Trans., 4, 465 (1997).
Conclusion
Complexes 1-3 have been successfully synthesized. The
structural as well as the coordination number of tin(IV) atoms
moieties of complexes 1-3 have been successfully characte-
rized quantitatively and qualitatively. Based on the preliminary
in vitro cytotoxic assay on human liver hepatocellular
carcinoma cells (HepG2) and antibacterial screening activity,
complex 3 [triphenyltin(IV)] showed better activity compared
to complexes 1 and 2 [diorganotin(IV)] but lower activity
compared to the reference drugs.
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ACKNOWLEDGEMENTS
The authors thank Universiti Tunku Abdul Rahman
(UTAR) for the UTAR Research Fund (Project No. IPSR/
RMC/UTARRF/C1-11/C07) and Universiti Sains Malaysia
(USM) for financial support as well as technical assistance
and facilities.
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