Research Article Novel Palladium(II) and Platinum(II ... · Journal of Chemistry F F NH 2 NH 2 NH 2 N NH 2 N N N CH 3 CH 3 Pt Cl Cl Cl Cl K 2 PtCl 4 [Pd(NCCH 3)4](BF 4)2 (BF 4)2 NCCH

Research ArticleNovel Palladium(II) and Platinum(II) Complexes witha Fluoropiperazinyl Based Ligand Exhibiting High Cytotoxicityand Anticancer Activity In Vitro

Kayed A Abu-Safieh1 Adnan S Abu-Surrah2 Hani D Tabba2 Huda A AlMasri1

Randa M Bawadi3 Fadila M Boudjelal3 and Lubna H Tahtamouni4

1Department of Chemistry Hashemite University PO Box 150459 Zarqa 13115 Jordan2Department of Chemistry and Earth Sciences College of Arts and Sciences Qatar University PO Box 2713 Doha Qatar3Department of Physiology and Biochemistry The University of Jordan Amman 11942 Jordan4Department of Biology and Biotechnology Hashemite University Zarqa 13115 Jordan

Correspondence should be addressed to Adnan S Abu-Surrah asurrahqueduqa

Received 10 December 2015 Accepted 31 January 2016

Academic Editor Josefina Pons

Copyright copy 2016 Kayed A Abu-Safieh et al This is an open access article distributed under the Creative Commons AttributionLicense which permits unrestricted use distribution and reproduction in any medium provided the original work is properlycited

cis-Dichloro-palladium(II) and cis-dichloro-platinum(II) complexes (2 4) of the general formula [M(N-N)Cl2] (M=Pd(II) and

Pt(II) N-N= 12-diamino-4-fluoro-5-(4-methyl-1-piperazinyl) benzene (DFMPB)) and the dicationic palladium(II) complex[Pd(N-N)(CH

3CN)2](BF4)2(3) have been prepared and characterized by elemental analysis 1H-NMR- mass spectroscopy and

IR spectroscopy The cytotoxic effect of these complexes against MDA-231 and MCF-7 human breast cancer cell lines and K562human leukemia cell line has been studiedThe influence was dose dependent and varies with cell typeThe palladium(II) complex(2) showed superior cytotoxic effect compared with the corresponding platinum(II) complex and the standard cisplatin whentested against all the above cell lines

1 Introduction

The similarity between the coordination chemistry of pal-ladium(II) and platinum(II) compounds has led to a largeresearch effort towards Pd(II) antitumor drugs that areefficient against Pt(II) resistant therapies and have less sideeffects [1] A key factor that might explain why platinum ismost useful comes from the ligand-exchange kinetics Thehydrolysis in palladium complexes is too rapid 105 timesfaster than that of the corresponding platinum analogues[2] These complexes dissociate readily in solution leadingto very reactive species that are unable to reach their phar-macological targets Accordingly compared to cisplatin thecorresponding cis-palladium cis-[Pd(NH

3)2Cl2] does not

show antitumor activity [3 4] Therefore if an antitumorpalladium complex is to be designed it must be stabilized bya chelate or a strongly coordinating nitrogen ligand [5]

Studies of platinum and palladium compounds withbiologically active carriers have yielded promising results in

the field of anticancer chemistry and there is potential forvarying the biological activity of these complexes by changingthe structure of the carrier [6 7] Significant advances haveemerged from this methodology of design [8ndash10]

Previously we reported the synthesis and molecularstructure of an enantiomerically pure trans-palladium(II)complex trans-[Pd(R)-(+)-bornyl-amine

2Cl2] that bears

the bulky amine ligand R-(+)-bornylamine (endo-(1R)-177-trimethylbicyclo[2-2-1]-heptan-2-amine) [11] The complexshowed similar antitumor activity against HeLa cells whencompared with the activity of the standard referencescisplatin carboplatin and oxaliplatin In addition a pal-ladium complex which contains the bulky nitrogen lig-and harmine (7-methoxy-1-methyl-9H-pyrido[34-b]indole)trans-[Pd(harmine)(DMSO)Cl

2] exhibited a greater cyto-

toxic activity against P388 L1210 and K562 cell lines thancisplatin [12 13]

Connors et al [14] and Meischen et al [15] have reporteddifferent platinum(II) complexes with aromatic amines such

Hindawi Publishing CorporationJournal of ChemistryVolume 2016 Article ID 7508724 7 pageshttpdxdoiorg10115520167508724

2 Journal of Chemistry

as cis-dichloro(4-chloro-12-phenylenediamine)platinum(II)and cis-dichloro(12-phenylenediamine)platinum(II) Al-though these complexes were less active than cisplatinthey have showed relevant biological activity against theL1210 leukemic cell lines de Almeida et al also reportedthat platinum(II) complexes with ligands derived from 12-phenylenediamine have potential cytotoxicity [16] The eval-uated compounds were less active in vitro than cisplatinCytotoxic evaluation results suggested that the presence of thestrong electron-withdrawing group in the aromatic ring leadto a decrease in the cytotoxicity against human cancer celllines such as MCF7 and EVSAT (mammary cancers) WiDr(colon cancer) and H226 (lung cancer)

4-Fluoro-5-(4-piperazinyl)-12-diaminobenzene has re-cently been proved to be a valuable intermediate for thesynthesis of various benzimidazole derivatives of biologi-cal interest for example as anticancer agents and bacte-ricides [17] Furthermore ferrocenyl-based complexes with5-fluoro-6-(4-substituted-1-piperazinyl)benzimidazoles havebeen reportedThese complexes were shown to have potencycomparable to that of azole-based antifungal agents (micona-zole) [18] It seems that the benzimidazoles with both fluorineandpiperazine as substituents lead to a considerable enhance-ment of the antibacterial potency [19] The substituted 1-piperazinyl derivative belongs to a group of DNA bindingfluorochromes used in chromosome staining and some ofthem exhibit antihistaminic activity [20 21]

It was proposed that a combination between Pd(II)or Pt(II) and 4-fluoro-5-(4-piperazinyl)-12-diaminobenzenecould led to the formation of compounds with potent anti-tumor activity To our knowledge as we are aware no studyof palladium(II) and platinum(II) complexes containing 4-fluoro-5-(4-piperazinyl)-12-diaminobenzene was reported

As an extension of our studies on both the coordinationchemistry of heteroatom containing ligands [22] and the bio-logical activity [23ndash25] of their metal complexes we describehere the synthesis and characterization of new square-planarplatinum(II) and palladium(II) complexes bearing the biden-tate chelate 12-diamino-4-fluoro-5-(4-methyl)-1-piperazinylbenzene (DFMPB) For comparison purposes the biologicalactivity of the corresponding water soluble dicationic diace-tonitrile palladium(II) complex was also investigated Theaim of our studywas to investigate the influence of DFMPB asa biologically active carrier on the cytotoxic properties of theplatinum(II) and palladium(II) complexes against MDA-231andMCF-7 human breast cancer cell lines andK562 leukemiacell line

2 Experimental

21 Materials and Instrumentation The complex[Pd(CH

3CN)4](BF4)2was purchased from Aldrich Reagent

grade chemicals were used as received unless otherwisestated 12-Diamino-4-fluoro-5-(4-methyl-1-piperazinyl) ben-zene was prepared as previously described [26] (Mp) 97∘CIR (KBr cmminus1) ] = 3382 (mbr) 3224 (m) 2943 (m) 2811 (w)1634 (m) and 1523 (s) 1H NMR (ppm DMSO-119889

6) 120575 = 627

(m H arom2H) 278 (br CH2CH2 4H) 241 (br CH

2CH2

4H) and 219 (s CH3 3H) MS (EI) () 225 (M+ 100)

Elemental analyses were performed using a EURO EA3000 instrument 1H-NMR spectra were recorded on aBruker spectrometer operating at 300MHz using DMSO-1198896as a solvent with TMS as an internal standard Infrared

spectra (KBr discs) were measured on a Nicolet-Magna-IR 560 Spectrophotometer Mass spectra (EI) were acquiredusing a Shimadzu-QP5050A Melting points were measuredby a Stuart ScientificmeltingApparatus (uncorrectedplusmn01∘C)

22 Synthesis of Complexes

221 cis-Dichloro(12-diamino-4-fluoro-5-(4-methyl-1-piper-azinyl)benzene)-palladium(II) ([Pd(DFMPB)Cl

2] 2) A fil-

tered solution of the ligand (1) (0065 g 029mmol) inacetone (30mL) was added to a solution of [Pd(PhCN)

2Cl2]

(050 g 130mmol) in acetone (50mL) with continuousstirring Upon addition an orange solid was formed After5 h stirring the precipitate was filtered washed with acetone(2 times 5mL) and Et

2O (2 times 10mL) and dried in vacuum

Yield of 041 g (78) Mp (dec) 230∘C Found C 3363H 454 N 1375 Anal Calc for C

11H17N4FPdCl

2 C 3289

H 427 N 1395 IR (KBr cmminus1) ] = 3389 (mbr) 3181 (m)3037 (m) 2725 (w) 1620 (w) 1513 (s) MS (EI) () 403 (M+10) 225 (M+-PdCl

2 45)

222 cis-Diacetonitrile(12-diamino-4-fluoro-5-(4-methyl-1-piperazinyl) benzene) palladium(II) bis(tetraflouroborate)([Pd(DFMPB)(CH

3CN)2](BF4)2) 3) To a solution of

[Pd(CH3CN)4](BF4)2

(039 g 088mmol) in acetonitrile(3mL) was added a filtered solution of the ligand (1)(088mmol) in acetonitrile (4mL) with continuous stirringat room temperature Upon addition a dark orange solutionwas formed After 5 h stirring the solvent was evaporated todryness and the isolated product was washed with Et

2O (2 times

5 mL) and dried in vacuumYield of 045 g (87) Mp (dec) 210∘C Found C 2760

H 380 N 1224 Anal Calc for C15H23N6F9PdB2sdot4H2O C

2736 H 352 N 1276 IR (KBr cmminus1) ] = 3391 (mbr) 3189(m) 3037 (m) 2715 (w) 1656 (m) 1509 (s) 1036 (ssh BF

4)

1H NMR (ppm DMSO) 120575 = 650 (m H arom2H) 351 (brCH2CH2 4H) 320 (br CH

2CH2 4H) 289 (s NCCH

3 6H)

200 (s CH3 3H) MS (EI) () 411 (M+-B

2F8 12) 370 (M+-

C2H3NB2F8 14) 225 (M+-C

4H6N2F8PdB2 100)

223 cis-Dichloro(12-diamino-4-fluoro-5-(4-methyl-1-piper-azinyl) benzene)-platinum(II) ([Pt(DFMPB)Cl

2] 4) To a

solution of K2[PtCl4] (042 g 1mmol) in water (4mL) was

added dropwise the ligand (1mmol) in methanol (5mL)with continuous stirring After 24 h in the dark at roomtemperature the brown solid formed was filtered washedwith water and dried


11H17N4FPtCl

2sdot2H2O C

2510 H 326 N 1065 IR (KBr cmminus1) ] = 3449 (mbr) 3051(mbr) 2745 (w) 1618 (m) 1516 (s) 1178 (m) MS (EI) () 491(M+ 10) 321 (M+-C

5H11N2Cl2 10)

Journal of Chemistry 3

F

F

NH2

NH2

NH2

NH2N

N

N

N

CH3

CH3

PtCl

Cl

Cl

Cl

K2PtCl4

[Pd(NCCH3)4](BF4)2

(BF4)2NCCH3

NCCH3

(1) (2)

(3)(4)

F

F

NH2

NH2

NH2

NH2

N

N

N

N

CH3

CH3

Pd

Pd[Pd(NCPh)2Cl2]

Scheme 1 Synthesis of the complexes used in the present study (2ndash4)

23 Biology

231 Cell Culture Human MDA-231 breast cancer cell linewas cultured in high glucose DMEM (Gibco USA) sup-plemented with 20 fetal calf serum (FCS) (EurocloneItaly) Human MCF-7 breast cancer cell line was cultured inRPMI-1640 medium (Euroclone Italy) supplemented with10 FCS Human K562 chronic myelogenous leukemic cellswere cultured in RPMI-1640 supplemented with 10 FCSTrypsin-EDTA (Lonza Switzerland) was routinely used forsubcultures Cell growth was accomplished at 37∘C in a 5carbon dioxide atmosphere

232 In Vitro Cytotoxicity (3-(45-Dimethylthiazol-2-yl)-25-diphenyltetrazolium bromide) MTT Test Cytotoxicity of thevarious complexes on MDA-231 MCF-7 and K562 cells wasevaluated by means of MTT (tetrazolium salt reduction)test [27 28] Briefly 5 times 104 viable cells were added toeach well of a 96-well tissue culture plate containing growthmedia supplemented with FCS [29] Cells were kept in ahumified 5 CO

2incubator at 37∘C for 24 h The complexes

(2ndash4 and cisplatin) were tested and for each complex sixconcentrations were prepared in growth media 01 05 255 25 and 50 120583gmL The complexes were solubilized in10 DMSO The next morning the different concentrationswere added and the cells were incubated for 24 h 48 h and72 h Freshly prepared MTT salt (3-(45-dimethylthiazol-2-yl)-25-diphenyltetrazolium bromide) (5mgmL) was addedto each well to give a final concentration of 05 120583g120583L Theplates were incubated for 4 h and the formation of formazancrystals was checked using an inverted microscope Equalvolume of 1 1 (200 120583L) DMSO and isopropanol mixturewas added to each well and incubated for 30ndash45min Theinhibition of cell growth induced by the various complexeswas detected by measuring the absorbance of each well at570 nm using a Statfax microplate reader For comparisonpurposes the cytotoxicity of cisplatin was evaluated underthe same experimental conditions

233 Clonogenic Assay 2 times 105 cells were seeded in tissueculture dishes containing growth media supplemented withFCS Cells were kept in a humified 5 CO

2incubator at

37∘C for 24 h Afterwards the medium was replaced and thecells were incubated for 3 h in the presence of an increasingconcentration of tested complexes (01 05 25 5 25 and50 120583gmL) Aliquots of 200 cells were seeded on soft agar forMDA-231 and MCF-7 cell lines and on methyl cellulose forK562 cell line and incubated for 12 days The colonies werethen stained and counted discarding colonies with less than50 cells The surviving fraction (SF) was calculated accordingto Alverdi et al [30] and Franken et al [31]

3 Results and Discussion

31 Chemistry The palladium(II) (2) and platinum(II)(4) complexes were prepared by treating each of thestarting materials [Pd(PhCN)

2Cl2] and K

2PtCl4 with

one equivalent of the diamine ligand 12-diamino-4-fluoro-5-(4-methyl-1-piperazinyl) benzene (DFMPB 1) atroom temperature (Scheme 1) The palladium(II) complex[Pd(DFMPB)(CH

3CN)2] (3) was prepared by reacting

the ligand (1) with [Pd(CH3CN)4](BF4)2

following ourpreviously published standard procedure [32]

The isolated compounds are microcrystalline or powder-like and stable at atmospheric conditions The new com-pounds have been characterized using variety of techniquesincluding elemental analysis IR- 1H-NMR-spectroscopyand mass- (EI-) spectroscopy

Elemental analyses of the complexes (2ndash4) showed thatthe metal to the fluoropiperazinyl ligand ratio in the dichlorocomplexes is 1 1The presence of the ligands in the complexeswas also confirmed by IR-analyses (Table 1) The peaks dueto the stretching vibration of the amine (N-H) showed slightshift to higher frequency This slight stiffness of vibrationrefers to complexation of the ligands with the metal (Table 1)Although some of the complexes were microcrystallineattempts to obtain crystals of suitable quality for an X-ray


Table 1 Analysis of the compoundsa

Entry Compound Compound number Color mp (dec) ∘C IRa

cmminus1

1 DFMPB 1 Colorless 97 3382 1634 15232 [(DFMPB)PdCl

2] 2 Orange 230 3389 1620 1513

3 [Pd(DFMPB)(CH3CN)2](BF4)2

3 Red 210 3391 1656 15094 [Pt(DFMPB) Cl

2] 4 Brown 240 3449 1618 1516

aN-H stretching absorption C=C absorption and in-plane NH2 scissoring absorption respectively

Table 2 MTT (3-(45-dimethylthiazol-2-yl)-25-diphenyltetrazolium bromide) results the values shown are IC50

a

Entry Compound Compound number MDA-231 MCF-7 K562

1 DFMPB 1(After 24 h)+ (After 24 h)+ (After 48 h)+

307 120583gmL 292 120583gmL 251 120583gmL13627 120583M 12961 120583M 1109120583M

2 [Pd(DFMPB)Cl2] 2

(After 24 h)+ (After 24 h)+ (After 48 h)+

311 120583gmL 288 120583gmL 239 120583gmL6383 120583M 7153 120583M 5936 120583M


3 No effectb(After 72 h)+ (After 48 h)+

501 120583gmL 436 120583gmL8529 120583M 7422 120583M

4 [Pt(DFMPB)Cl2] 4


428 120583gmL 446 120583gmL 354120583gmL8712 120583M 9079 120583M 721 120583M

5 Cisplatin(After 48 h)+ (After 24 h)+ (After 48 h)+

430 120583gmL 401 120583gmL 259 120583gmL14331 120583M 13365 120583M 8632 120583M

aThe results are shown in terms of IC50 values (the concentration needed to inhibit 50 of the cellular proliferation) For comparison purposes the cytotoxicityof cisplatin a standard antitumor drug was tested under the same conditions+The time it took for the drug to affect cell viabilitybAfter 72 h of drug addition the drug killed at most 15 of the cells at 50120583gmL

structure determination were unsuccessful and could bedue to the marginal solubility of the dichloride complexesTherefore only the solution behavior of complex 3 wasdetermined by NMR spectroscopy in DMSO-119889

6at room

temperature The 1H-NMR experiments showed that themetal to ligand ratio is 1 1 It has been indicated that slightshift to higher delta values of the ligand signals is observedupon coordination with palladium

32 Biological Investigations The cytotoxic activities of theligand (1) and the corresponding complexes (2ndash4) wereevaluated against human MDA-231 breast cancer cell linehuman MCF-7 breast cancer cell line and human K562leukemia cell line The results are shown in Table 2 in termsof IC

50values (the concentration needed to inhibit 50

of the cellular proliferation) For comparison purposes thecytotoxicity of cisplatin a standard antitumor drug wastested under the same conditions

The obtained data (Table 2) indicate a superior activity forthe palladium(II) complex [Pd(DFMPB)Cl

2] (2) against all

cell lines MDA-231 and MCF-7 breast cancer cell lines andK562 leukemia cell lines (IC

50= 6383 7153 and 5936 120583M)

under similar condition It showed the highest activity among

the compounds investigated in the present study In additionthe organic carrier (ligand DFMPB 1) showed substantialactivity compared with the standard antitumor drug cis-platin and the platinum(II) complex (4) against MDA-231and MCF-7 human breast cancer cell lines The noticeableactivity of the organic ligand could be due to the presenceof the piperazinyl moiety Previous investigation showed thatthe presence of a strong electron-withdrawing group in thearomatic ring leads to a decrease in the cytotoxic activity ofplatinum(II) complexes [16]

However the platinum(II) complex [Pt(DFMPB)Cl2] (4)

is more active than cisplatin against only MDA-231 breastcancer and human K562 leukemia cell linesThe correspond-ing dicationic complex (3) showed higher cytotoxic activitycompared with cisplatin and the ligand only against K562leukemia cell line

According to Table 2 coordination of the organic bio-logical carrier with palladium significantly increases its bio-logical activity towards all cancer cell lines However thecorresponding platinum(II) complex showed lower activitythan compounds 1 and 2 This behavior could be due tothe relatively lower rate of hydrolysis of the palladium(II)complex caused by the coordination with the ridged aromatic


Cisplatin12

43

0

01

02

03

04

05

06

07

08

09

1

Surv

ivin

g fr

actio

n

10 20 30 40 50 600Drug concentration (120583gmL)

(a)

Cisplatin12

43

0

01

02

03

04

05

06

07

08

09

1

Surv

ivin

g fr

actio

n


(b)

Cisplatin12

43

10 20 30 40 50 6000

01

02

03

04

05

06

07

08

09

1

Surv

ivin

g fr

actio

n

Drug concentration (120583gmL)

(c)

Figure 1 The antiproliferative activity of drugs (2ndash4 and the standard antitumor drug cisplatin) was evaluated using the clonogenic assayagainst (a) human MDA-231 breast cancer cell line (b) human MCF-7 breast cancer cell line and (c) human K562 leukemia cell line Thesurviving fraction was calculated as number of colonies after treatment[number of seeded cells (200 cells) times plating efficiency (PE)] wherePE = number of colonies[number of seeded cells (200 cells) times 100]

diamine ligand (1) However due to the relatively lowerstability of the dicationic complex (3) the activity towardshuman MCF-7 breast cancer cell declined

Based on the cytotoxic activity results above it seemsthat both electronic properties and bulkiness of the ligandhave a noticeable influence not only on the activity of thepalladium(II) but also on its stability The antiproliferativeactivity of the new complexes was also evaluated by studyingthe effect on clonal growth capacity of cells (Figures 1(a)ndash1(c))Theobtained data suggest that the palladiumderivativesshow a significant antiproliferative activity similar to that ofthe reference drug (cisplatin)

4 Conclusions

Several strategies have been utilized in order to design a betterantitumor drug Studies of platinum and palladium com-pounds with biologically active carriers have yielded promis-ing results in the field of anticancer chemistry In the presentstudy we showed that the biologically active compound 12-diamino-4-fluoro-5-(4-methyl-1-piperazinyl)benzene couldgenerate palladium(II) and platinum(II) complexes with highcytotoxic activity against MDA-231 and MCF-7 breast cancercell lines and K562 leukemia cell lines Our experimentsillustrate that the activity against the above cell lines for the


palladium(II) complex (2) (IC50= 6383 7153 and 5936 120583M

resp) is much better than that for the corresponding plat-inum(II) complex (4) (IC

50= 8712 9079 and 721 120583M resp)

and cisplatin (IC50= 14331 13365 and 8632 120583M resp) under

similar conditions

Disclosure

Current address of Kayed A Abu-Safieh is ChemistryDepartment College of Science King Khalid UniversityPO Box 9004 Abha Saudi Arabia The permanent addressof Adnan S Abu-Surrah is Department of ChemistryHashemite University P O Box 150459 Zarqa 13115 Jordan

Conflict of Interests

The authors declare that there is no conflict of interestsregarding the publication of this paper

Acknowledgment

Financial support by the Hashemite University is gratefullyacknowledged

References

[1] A M Montana and C Batalla ldquoThe rational design of anti-cancer platinum complexes the importance of the structure-activity relationshiprdquo Current Medicinal Chemistry vol 16 no18 pp 2235ndash2260 2009

[2] A S Abu-Surrah andM Kettunen ldquoPlatinum group antitumorchemistry design and development of new anticancer drugscomplementary to cisplatinrdquo Current Medicinal Chemistry vol13 no 11 pp 1337ndash1357 2006

[3] F L Wimmer S Wimmer P Castan S Cros N Johnsonand E Colacio-Rodrigez ldquoThe antitumor activity of somepalladium(II) complexes with chelating ligandsrdquo AnticancerResearch vol 9 no 3 pp 791ndash794 1989

[4] G Zhao H Lin Y Ping et al ldquoEthylenediamine-palladium(II)complexes with pyridine and its derivatives synthesis molecu-lar structure and initial antitumor studiesrdquo Journal of InorganicBiochemistry vol 73 no 3 pp 145ndash149 1999

[5] H Mansuri-Torshizi T S Srivastava H K Parekh andM P Chitnis ldquoSynthesis spectroscopic cytotoxic and DNAbinding studies of binuclear 221015840-bipyridine-platinum(II) and-palladium (II) complexes of meso-1205721205721015840-diaminoadipic andmeso-1205721205721015840-diaminosuberic acidsrdquo Journal of Inorganic Bio-chemistry vol 45 no 2 pp 135ndash148 1992

[6] Y-P Ho K K W To S C F Au-Yeung X Wang G Lin andX Han ldquoPotential new antitumor agents from an innovativecombination of demethylcantharidin a modified traditionalchinese medicine with a platinummoietyrdquo Journal of MedicinalChemistry vol 44 no 13 pp 2065ndash2068 2001

[7] T V Polyanskaya I Kazhdan D M Motley and J AWalmsley ldquoSynthesis characterization and cytotoxicity studiesof palladium(II)ndashproflavine complexesrdquo Journal of InorganicBiochemistry vol 104 no 11 pp 1205ndash1213 2010

[8] F Z Wimmer S Wimmer P Castan S Cros N Johnsonand E Colacio-Rodrigez ldquoThe antitumor activity of some

palladium(II) complexes with chelating ligandsrdquo AnticancerResearch vol 9 no 3 pp 791ndash794 1989

[9] G Zhao H Lin P Yu et al ldquoEthylenediamine-palladium(II)complexes with pyridine and its derivatives synthesis molecu-lar structure and initial antitumor studiesrdquo Journal of InorganicBiochemistry vol 73 no 3 pp 745ndash149 1999

[10] A S Abu-Surrah H H Al-Sarsquodoni and M Y AbdallaldquoPalladium based chemotherapeutic agents Routes towardscomplexes with good antitumor activityrdquo Cancer Therapy vol6 pp 1ndash10 2008

[11] A S Abu-Surrah T A K Al-Allaf L J Rashan M Klingaand M Leskela ldquoSynthesis crystal structure and initialbiological evaluation of the new enantiomerically purechiral palladium(II) complex trans-bisendo-(1R)-177-tri-methylbicyclo[221]-heptan-2-aminopalladium(II)dichloriderdquoEuropean Journal of Medicinal Chemistry vol 37 no 11 pp919ndash922 2002

[12] T A K Al-Allaf and L J Rashan ldquoSynthesis and cytotoxic eval-uation of the first trans-palladium(II) complex with naturallyoccurring alkaloid harminerdquo European Journal of MedicinalChemistry vol 33 no 10 pp 817ndash820 1998

[13] T A K Al-Allaf L J Rashan M T Ayoub and M H AddayUK Patent No2 304 712 1997

[14] T A Connors M Jones W C J Ross P D Braddock A RKhokhar and M L Tobe ldquoNew platinum complexes with anti-tumour activityrdquo Chemico-Biological Interactions vol 5 no 6pp 415ndash424 1972

[15] S J Meischen G R Gale L M Lake et al ldquoAntileukemic prop-erties of organoplatinum complexesrdquo Journal of the NationalCancer Institute vol 57 no 4 pp 841ndash845 1976

[16] M V de Almeida J D S Chaves A P S Fontes E T Cesar andMGielen ldquoSynthesis and characterization of platinum(II) com-plexes from trifluoromethyl phenylenediamine picoline andN-benzyl ethylenediamine derivativesrdquo Journal of the BrazilianChemical Society vol 17 no 7 pp 1266ndash1273 2006

[17] R J Abdel-Jalil R A Al-Qawasmeh W Voelter PHeeg M M El-Abadelah and S S Sabri ldquoSynthesis andproperties of some 23-disubstituted 6-fluoro-7-(4-methyl-1-piperazinyl)quinoxalinesrdquo Journal of Heterocyclic Chemistryvol 37 no 5 pp 1273ndash1275 2000

[18] R J Abdel-Jalil and W Voelter ldquoSynthesis of new 2-ferrocenyl-5-fluoro-6-(4-substituted-1-piperazinyl)-1H-benzimidazoles ofpotential biological interestrdquo Journal of Heterocyclic Chemistryvol 42 no 1 pp 67ndash71 2005

[19] M P Wentland D M Bailey J B Cornett R A DobsonR G Powles and R B Wagner ldquoNovel amino-substituted3-quinolinecarboxylic acid antibacterial agents synthesis andstructure-activity relationshipsrdquo Journal of Medicinal Chem-istry vol 27 no 9 pp 1103ndash1108 1984

[20] G A Daxhelet M M Coene P P Hoet and C G CocitoldquoSpectrofluorometry of dyes with DNAs of different basecomposition and conformationrdquo Analytical Biochemistry vol179 no 2 pp 401ndash403 1989

[21] R Iemura and H Ohtaka ldquoQuantitative structure-activityrelationships of H1-antihistaminic benzimidazole derivativesrdquoChemical and Pharmaceutical Bulletin vol 37 no 4 pp 967ndash972 1989

[22] K LappalainenK Yliheikkila A SAbu-Surrah et al ldquoIron(II)-and cobalt(II) complexes with tridentate bis(imino)pyridine


nitrogen ligands bearing chiral bulky aliphatic and aro-matic substituents crystal structure of [CoCl

22 6-bis[R-(+)-

(bornylimino)methyl]pyridine]rdquo Zeitschrift fur Anorganischeund Allgemeine Chemie vol 631 no 4 pp 763ndash768 2005

[23] A S Abu-Surrah K A Abu Safieh I M Ahmad et al ldquoNewpalladium(II) complexes bearing pyrazole-based Schiff baseligands synthesis characterization and cytotoxicityrdquo EuropeanJournal of Medicinal Chemistry vol 45 no 2 pp 471ndash475 2010

[24] A S Abu-Surrah T A K Al-Allaf M Klinga and MAhlgrend ldquoChiral palladium(II) and platinum(II) complexes ofdiaminocyclohexane X-ray structures of (1R2R)-(-)-12-diami-nocyclohexane dihydrochloride and its corresponding oxalatoplatinum(II) complexrdquo Polyhedron vol 22 no 12 pp 1529ndash1534 2003

[25] T A K Al-Allaf L J Rashan A S Abu-Surrah R Fawziand M Steiman ldquoChemical properties and cytotoxic activityof complexes of platinum(II) and palladium(II) containingdmso and various anions synthesis and structural charac-terization of [Pt(dmso)

2O2(CO)2CCH2CH2CH2]rdquo Transition

Metal Chemistry vol 23 no 4 pp 403ndash406 1998[26] M M El-Abadelah S S Sabri M H Abu-Zarga and R J

Abdel-Jalil ldquoSubstituted benzimidazoles Part 1 Synthesis andproperties of some 2-aryl-5-fluoro-6-(4-methyl-1-piperazinyl)-1H-benzimidazolesrdquo Heterocycles vol 41 no 2 pp 2713ndash27281995

[27] T Mosmann ldquoRapid colorimetric assay for cellular growth andsurvival application to proliferation and cytotoxicity assaysrdquoJournal of Immunological Methods vol 65 no 1-2 pp 55ndash631983

[28] G Fotakis and J A Timbrell ldquoIn vitro cytotoxicity assayscomparison of LDH neutral red MTT and protein assay inhepatoma cell lines following exposure to cadmium chloriderdquoToxicology Letters vol 160 no 2 pp 171ndash177 2006

[29] R Freshney Culture of Animal Cells A Manual of BasicTechnique and Specialized Applications John Wiley amp SonsHoboken NJ USA 2000

[30] V Alverdi L Giovagnini C Marzano et al ldquoCharacterizationstudies and cytotoxicity assays of Pt(II) and Pd(II) dithiocar-bamate complexes by means of FT-IR NMR spectroscopy andmass spectrometryrdquo Journal of Inorganic Biochemistry vol 98no 6 pp 1117ndash1128 2004

[31] N A P Franken H M Rodermond J Stap J Haveman and Cvan Bree ldquoClonogenic assay of cells in vitrordquo Nature Protocolsvol 1 no 5 pp 2315ndash2319 2006

[32] A S Abu-Surrah G Eckert W Pechhold W Wilke andB Rieger ldquoUltrahigh molecular weight alternating propeneethenecarbon monoxide terpolymers with elastic propertiesrdquoMacromolecular Rapid Communications vol 17 no 8 pp 559ndash565 1996

Submit your manuscripts athttpwwwhindawicom

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Inorganic ChemistryInternational Journal of

Hindawi Publishing Corporation httpwwwhindawicom Volume 2014

International Journal ofPhotoenergy


Carbohydrate Chemistry

International Journal of


Journal of

Chemistry


Advances in

Physical Chemistry

Hindawi Publishing Corporationhttpwwwhindawicom

Analytical Methods in Chemistry

Journal of

Volume 2014

Bioinorganic Chemistry and ApplicationsHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

SpectroscopyInternational Journal of


The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Medicinal ChemistryInternational Journal of


Chromatography Research International


Applied ChemistryJournal of



Theoretical ChemistryJournal of


Journal of

Spectroscopy

Analytical ChemistryInternational Journal of


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Organic Chemistry International

ElectrochemistryInternational Journal of



CatalystsJournal of


as cis-dichloro(4-chloro-12-phenylenediamine)platinum(II)and cis-dichloro(12-phenylenediamine)platinum(II) Al-though these complexes were less active than cisplatinthey have showed relevant biological activity against theL1210 leukemic cell lines de Almeida et al also reportedthat platinum(II) complexes with ligands derived from 12-phenylenediamine have potential cytotoxicity [16] The eval-uated compounds were less active in vitro than cisplatinCytotoxic evaluation results suggested that the presence of thestrong electron-withdrawing group in the aromatic ring leadto a decrease in the cytotoxicity against human cancer celllines such as MCF7 and EVSAT (mammary cancers) WiDr(colon cancer) and H226 (lung cancer)

4-Fluoro-5-(4-piperazinyl)-12-diaminobenzene has re-cently been proved to be a valuable intermediate for thesynthesis of various benzimidazole derivatives of biologi-cal interest for example as anticancer agents and bacte-ricides [17] Furthermore ferrocenyl-based complexes with5-fluoro-6-(4-substituted-1-piperazinyl)benzimidazoles havebeen reportedThese complexes were shown to have potencycomparable to that of azole-based antifungal agents (micona-zole) [18] It seems that the benzimidazoles with both fluorineandpiperazine as substituents lead to a considerable enhance-ment of the antibacterial potency [19] The substituted 1-piperazinyl derivative belongs to a group of DNA bindingfluorochromes used in chromosome staining and some ofthem exhibit antihistaminic activity [20 21]

It was proposed that a combination between Pd(II)or Pt(II) and 4-fluoro-5-(4-piperazinyl)-12-diaminobenzenecould led to the formation of compounds with potent anti-tumor activity To our knowledge as we are aware no studyof palladium(II) and platinum(II) complexes containing 4-fluoro-5-(4-piperazinyl)-12-diaminobenzene was reported

As an extension of our studies on both the coordinationchemistry of heteroatom containing ligands [22] and the bio-logical activity [23ndash25] of their metal complexes we describehere the synthesis and characterization of new square-planarplatinum(II) and palladium(II) complexes bearing the biden-tate chelate 12-diamino-4-fluoro-5-(4-methyl)-1-piperazinylbenzene (DFMPB) For comparison purposes the biologicalactivity of the corresponding water soluble dicationic diace-tonitrile palladium(II) complex was also investigated Theaim of our studywas to investigate the influence of DFMPB asa biologically active carrier on the cytotoxic properties of theplatinum(II) and palladium(II) complexes against MDA-231andMCF-7 human breast cancer cell lines andK562 leukemiacell line

2 Experimental

21 Materials and Instrumentation The complex[Pd(CH

3CN)4](BF4)2was purchased from Aldrich Reagent

grade chemicals were used as received unless otherwisestated 12-Diamino-4-fluoro-5-(4-methyl-1-piperazinyl) ben-zene was prepared as previously described [26] (Mp) 97∘CIR (KBr cmminus1) ] = 3382 (mbr) 3224 (m) 2943 (m) 2811 (w)1634 (m) and 1523 (s) 1H NMR (ppm DMSO-119889

6) 120575 = 627

(m H arom2H) 278 (br CH2CH2 4H) 241 (br CH

2CH2

4H) and 219 (s CH3 3H) MS (EI) () 225 (M+ 100)

Elemental analyses were performed using a EURO EA3000 instrument 1H-NMR spectra were recorded on aBruker spectrometer operating at 300MHz using DMSO-1198896as a solvent with TMS as an internal standard Infrared

spectra (KBr discs) were measured on a Nicolet-Magna-IR 560 Spectrophotometer Mass spectra (EI) were acquiredusing a Shimadzu-QP5050A Melting points were measuredby a Stuart ScientificmeltingApparatus (uncorrectedplusmn01∘C)

22 Synthesis of Complexes

221 cis-Dichloro(12-diamino-4-fluoro-5-(4-methyl-1-piper-azinyl)benzene)-palladium(II) ([Pd(DFMPB)Cl

2] 2) A fil-

tered solution of the ligand (1) (0065 g 029mmol) inacetone (30mL) was added to a solution of [Pd(PhCN)

2Cl2]

(050 g 130mmol) in acetone (50mL) with continuousstirring Upon addition an orange solid was formed After5 h stirring the precipitate was filtered washed with acetone(2 times 5mL) and Et

2O (2 times 10mL) and dried in vacuum


11H17N4FPdCl

2 C 3289

H 427 N 1395 IR (KBr cmminus1) ] = 3389 (mbr) 3181 (m)3037 (m) 2725 (w) 1620 (w) 1513 (s) MS (EI) () 403 (M+10) 225 (M+-PdCl

2 45)

222 cis-Diacetonitrile(12-diamino-4-fluoro-5-(4-methyl-1-piperazinyl) benzene) palladium(II) bis(tetraflouroborate)([Pd(DFMPB)(CH

3CN)2](BF4)2) 3) To a solution of

[Pd(CH3CN)4](BF4)2

(039 g 088mmol) in acetonitrile(3mL) was added a filtered solution of the ligand (1)(088mmol) in acetonitrile (4mL) with continuous stirringat room temperature Upon addition a dark orange solutionwas formed After 5 h stirring the solvent was evaporated todryness and the isolated product was washed with Et

2O (2 times

5 mL) and dried in vacuumYield of 045 g (87) Mp (dec) 210∘C Found C 2760

H 380 N 1224 Anal Calc for C15H23N6F9PdB2sdot4H2O C

2736 H 352 N 1276 IR (KBr cmminus1) ] = 3391 (mbr) 3189(m) 3037 (m) 2715 (w) 1656 (m) 1509 (s) 1036 (ssh BF

4)

1H NMR (ppm DMSO) 120575 = 650 (m H arom2H) 351 (brCH2CH2 4H) 320 (br CH

2CH2 4H) 289 (s NCCH

3 6H)

200 (s CH3 3H) MS (EI) () 411 (M+-B

2F8 12) 370 (M+-

C2H3NB2F8 14) 225 (M+-C

4H6N2F8PdB2 100)

223 cis-Dichloro(12-diamino-4-fluoro-5-(4-methyl-1-piper-azinyl) benzene)-platinum(II) ([Pt(DFMPB)Cl

2] 4) To a

solution of K2[PtCl4] (042 g 1mmol) in water (4mL) was

added dropwise the ligand (1mmol) in methanol (5mL)with continuous stirring After 24 h in the dark at roomtemperature the brown solid formed was filtered washedwith water and dried


11H17N4FPtCl

2sdot2H2O C

2510 H 326 N 1065 IR (KBr cmminus1) ] = 3449 (mbr) 3051(mbr) 2745 (w) 1618 (m) 1516 (s) 1178 (m) MS (EI) () 491(M+ 10) 321 (M+-C

5H11N2Cl2 10)


F

F

NH2

NH2

NH2

NH2N

N

N

N

CH3

CH3

PtCl

Cl

Cl

Cl

K2PtCl4

[Pd(NCCH3)4](BF4)2

(BF4)2NCCH3

NCCH3

(1) (2)

(3)(4)

F

F

NH2

NH2

NH2

NH2

N

N

N

N

CH3

CH3

Pd

Pd[Pd(NCPh)2Cl2]


23 Biology






2incubator at




2Cl2] and K

2PtCl4 with










cmminus1


2] 2 Orange 230 3389 1620 1513


3 Red 210 3391 1656 15094 [Pt(DFMPB) Cl

2] 4 Brown 240 3449 1618 1516



a



307 120583gmL 292 120583gmL 251 120583gmL13627 120583M 12961 120583M 1109120583M

2 [Pd(DFMPB)Cl2] 2


311 120583gmL 288 120583gmL 239 120583gmL6383 120583M 7153 120583M 5936 120583M



501 120583gmL 436 120583gmL8529 120583M 7422 120583M

4 [Pt(DFMPB)Cl2] 4


428 120583gmL 446 120583gmL 354120583gmL8712 120583M 9079 120583M 721 120583M


430 120583gmL 401 120583gmL 259 120583gmL14331 120583M 13365 120583M 8632 120583M



6at room






2] (2) against all


50= 6383 7153 and 5936 120583M)







Cisplatin12

43

0

01

02

03

04

05

06

07

08

09

1

Surv

ivin

g fr

actio

n


(a)

Cisplatin12

43

0

01

02

03

04

05

06

07

08

09

1

Surv

ivin

g fr

actio

n


(b)

Cisplatin12

43

10 20 30 40 50 6000

01

02

03

04

05

06

07

08

09

1

Surv

ivin

g fr

actio

n


(c)




4 Conclusions





50= 8712 9079 and 721 120583M resp)


similar conditions

Disclosure




Acknowledgment


References


























22 6-bis[R-(+)-























Journal of

Chemistry


Advances in

Physical Chemistry



Journal of

Volume 2014














Journal of

Spectroscopy



Journal of


Quantum Chemistry






CatalystsJournal of


F

F

NH2

NH2

NH2

NH2N

N

N

N

CH3

CH3

PtCl

Cl

Cl

Cl

K2PtCl4

[Pd(NCCH3)4](BF4)2

(BF4)2NCCH3

NCCH3

(1) (2)

(3)(4)

F

F

NH2

NH2

NH2

NH2

N

N

N

N

CH3

CH3

Pd

Pd[Pd(NCPh)2Cl2]


23 Biology






2incubator at




2Cl2] and K

2PtCl4 with










cmminus1


2] 2 Orange 230 3389 1620 1513


3 Red 210 3391 1656 15094 [Pt(DFMPB) Cl

2] 4 Brown 240 3449 1618 1516



a



307 120583gmL 292 120583gmL 251 120583gmL13627 120583M 12961 120583M 1109120583M

2 [Pd(DFMPB)Cl2] 2


311 120583gmL 288 120583gmL 239 120583gmL6383 120583M 7153 120583M 5936 120583M



501 120583gmL 436 120583gmL8529 120583M 7422 120583M

4 [Pt(DFMPB)Cl2] 4


428 120583gmL 446 120583gmL 354120583gmL8712 120583M 9079 120583M 721 120583M


430 120583gmL 401 120583gmL 259 120583gmL14331 120583M 13365 120583M 8632 120583M



6at room






2] (2) against all


50= 6383 7153 and 5936 120583M)







Cisplatin12

43

0

01

02

03

04

05

06

07

08

09

1

Surv

ivin

g fr

actio

n


(a)

Cisplatin12

43

0

01

02

03

04

05

06

07

08

09

1

Surv

ivin

g fr

actio

n


(b)

Cisplatin12

43

10 20 30 40 50 6000

01

02

03

04

05

06

07

08

09

1

Surv

ivin

g fr

actio

n


(c)




4 Conclusions





50= 8712 9079 and 721 120583M resp)


similar conditions

Disclosure




Acknowledgment


References


























22 6-bis[R-(+)-























Journal of

Chemistry


Advances in

Physical Chemistry



Journal of

Volume 2014














Journal of

Spectroscopy



Journal of


Quantum Chemistry






CatalystsJournal of




cmminus1


2] 2 Orange 230 3389 1620 1513


3 Red 210 3391 1656 15094 [Pt(DFMPB) Cl

2] 4 Brown 240 3449 1618 1516



a



307 120583gmL 292 120583gmL 251 120583gmL13627 120583M 12961 120583M 1109120583M

2 [Pd(DFMPB)Cl2] 2


311 120583gmL 288 120583gmL 239 120583gmL6383 120583M 7153 120583M 5936 120583M



501 120583gmL 436 120583gmL8529 120583M 7422 120583M

4 [Pt(DFMPB)Cl2] 4


428 120583gmL 446 120583gmL 354120583gmL8712 120583M 9079 120583M 721 120583M


430 120583gmL 401 120583gmL 259 120583gmL14331 120583M 13365 120583M 8632 120583M



6at room






2] (2) against all


50= 6383 7153 and 5936 120583M)







Cisplatin12

43

0

01

02

03

04

05

06

07

08

09

1

Surv

ivin

g fr

actio

n


(a)

Cisplatin12

43

0

01

02

03

04

05

06

07

08

09

1

Surv

ivin

g fr

actio

n


(b)

Cisplatin12

43

10 20 30 40 50 6000

01

02

03

04

05

06

07

08

09

1

Surv

ivin

g fr

actio

n


(c)




4 Conclusions





50= 8712 9079 and 721 120583M resp)


similar conditions

Disclosure




Acknowledgment


References


























22 6-bis[R-(+)-























Journal of

Chemistry


Advances in

Physical Chemistry



Journal of

Volume 2014














Journal of

Spectroscopy



Journal of


Quantum Chemistry






CatalystsJournal of


Cisplatin12

43

0

01

02

03

04

05

06

07

08

09

1

Surv

ivin

g fr

actio

n


(a)

Cisplatin12

43

0

01

02

03

04

05

06

07

08

09

1

Surv

ivin

g fr

actio

n


(b)

Cisplatin12

43

10 20 30 40 50 6000

01

02

03

04

05

06

07

08

09

1

Surv

ivin

g fr

actio

n


(c)




4 Conclusions





50= 8712 9079 and 721 120583M resp)


similar conditions

Disclosure




Acknowledgment


References


























22 6-bis[R-(+)-























Journal of

Chemistry


Advances in

Physical Chemistry



Journal of

Volume 2014














Journal of

Spectroscopy



Journal of


Quantum Chemistry






CatalystsJournal of




50= 8712 9079 and 721 120583M resp)


similar conditions

Disclosure




Acknowledgment


References


























22 6-bis[R-(+)-























Journal of

Chemistry


Advances in

Physical Chemistry



Journal of

Volume 2014














Journal of

Spectroscopy



Journal of


Quantum Chemistry






CatalystsJournal of



22 6-bis[R-(+)-























Journal of

Chemistry


Advances in

Physical Chemistry



Journal of

Volume 2014














Journal of

Spectroscopy



Journal of


Quantum Chemistry






CatalystsJournal of










Journal of

Chemistry


Advances in

Physical Chemistry



Journal of

Volume 2014














Journal of

Spectroscopy



Journal of


Quantum Chemistry






CatalystsJournal of

Documents

Research Article Novel Palladium(II) and Platinum(II ... · Journal of Chemistry F F NH 2 NH 2 NH 2 N NH 2 N N N CH 3 CH 3 Pt Cl Cl Cl Cl K 2 PtCl 4 [Pd(NCCH 3)4](BF 4)2 (BF 4)2 NCCH