Platinum and Palladium Complexes as Promising Sources for Antitumor Treatments

Abstract

There is a need for new, safer, and more effective agents to treat cancer. Cytostatics that have transition metals at their core have attracted renewed interest from scientists. Researchers are attempting to use chemotherapeutics, such as cisplatin, in combination therapy (i.e., in order to enhance their effectiveness). Moreover, studies are being carried out to modify molecules, by developing them into multinuclear structures, linking different compounds to commonly used drugs, or encapsulating them in nanoparticles to improve pharmacokinetic parameters, and increase the selectivity of these drugs. Therefore, we attempted to organize recent drug findings that contain palladium and platinum atoms in their structures.

Keywords: anticancer treatments; palladium complexes; platinum complexes.

Figure 1

Structures of clinically used platinum anticancer drugs (1—cisplatin, 2—carboplatin, 3—nedaplatin, 4—lobaplatin, 5—oxaliplatin, 6—picoplatin, 7—miboplatin, 8—enloplatin).

Figure 2

Chemical structures of carbonic anhydrase IX targeted platinum(IV) complexes with (9) cisplatin and (10) oxaliplatin core.

Figure 3

Structures of the new complexes of platinum(IV) with dihydro-2-quinolone—(11) mono DHQLO oxaliplatin and (12) dual DHQLO oxaliplatin complex.

Figure 4

Structures of platinum(II) complexes with terpyridine derivatives exhibiting anticancer activity—(13) complex with 2,6-bis(2-pyridyl)-4[1H]-pyridone and (14) 2,2′-((2-([2,2′;6′,2″-terpyridin]-4′-yloxy)ethyl)azanediyl)bis-(ethan-1-ol).

Figure 5

Novel platinum complexes with glycine derivatives.

Figure 6

Structures of platinum(II) complexes with (15) 2,6-di-tert-butyl-4-(1-phenyl-1H-benzimidazol-2-2yl) phenol, (16) N,N-dimethyl-4-(1-phenyl-1H-benzimidazol-2-yl) aniline, and (17) 4-(1H-benzimidazol-2-yl)-N,N-dimethylaniline.

Figure 7

Novel cationic platinum(II)-complex (caPt(II)-complex).

Figure 8

Novel platinum complex with folic acid.

Figure 9

Structures of berenil-platinum(II) complexes (18—Pt₂(isopropylamine)₄berenil₂ and 19—Pt₂(piperidine)₄(berenil)₂).

Figure 10

Structures of the new synthesized platinum structures with (20) 4,4′-bipyridine, (21) 1,2-bis(4-pyridyl)ethane and (22) 1,2-bis(4-pyridyl)ethene.

Figure 11

Structure of the new trinuclear platinum complex (MTPC).

Figure 12

New palladium(II) complexes with (23) picolinic acid, (24) isonicotinic acid, (25) nicotinamide, and these complexes with an additional caffeine ligand (26–28).

Figure 13

Structures of palladium(II) complexes with 2-hydrazinopyridine conjugated with (29) oxalate, (30) malonate, and (31) pyrophosphate ligand.

Figure 14

Structures of palladium (II) complexes with (32) 2-acetyl-5-methylthiopene thiosemicarbazone, (33) (2E)-2-[1-(5-Methyl-2-thienyl)ethylidene]hydrazinecarbothioamide, and (34) (2E)-2-[(2E)-3-phenyl-2-propen-1-ylidene]hydrazinecarbothioamide ligands.

Figure 15

Structures of bis(phosphinite) palladium(II) complexes.

Figure 16

Complex AJ-5—binuclear palladacycle complex.

Figure 17

Palladium(II) binuclear complexes with quinoxaline (37), quinazoline (38), and phthalazine (39).

Figure 18

Structure of dinuclear palladium (II)—spermine complex (Pd₂Spm).

Figure 19

Structure of dinuclear novel palladium (II) complex with nitroimidazole.

Figure 20

Structure of palladium derivative conjugated with 2,6-dimethyl-4-nitro-pyridine (dmnp).