Platinum complexes iproplatin

The only prominent antitumor tetravalent platinum complex so far is iproplatin (102). In vitro it has been shown to cause interstrand DNA-breaking and cross linking. Free radical scavengers inhibit these effects. The complex is less neurotoxic and less nephrotoxic than cisplatin. Its synthesis begins with hydrogen peroxide oxidation of cis-dichlorobis(isopropvlamine) platinum (100) to the dimethylacetamide complex 101. The latter is heated in vacuum to liberate iproplatin [25]. 

Fig. 2A-C. Structure of the second generation antitumor platinum complexes carboplatin (A), spiroplatin (B), and iproplatin (C)...

Potency. Nearly all of the platinum(IV) complexes tested are less potent than cisplatin, with the single exception of (25) [74]. Iproplatin is 4-16-times less potent, with multidose schedules tending toward the higher number whether measured by antitumour O.D. or LDS0 determinations. Oxoplatin, (23), is likewise about 10-times less potent than cisplatin. 

Iproplatin [CHIP, cis-dichloro-trans-dihydroxo-bis(isopropylamine) plati-num(iv) see Figure 1 for structure], like carboplatin, was selected for clinical evaluation because of its favourable efficacy profile in preclinical studies, i.e. less nephrotoxicity but antitumour activity comparable to that of cisplatin. Iproplatin was the first quadrivalent platinum(iv) complex possessing an octahedral configuration, rather than the square-planar configuration of cisplatin and... 

---