Antitumor activity organotin

When the antitumor activity of cisplatin was discovered, several research groups started to investigate the possible therapeutic applications of other metal-based, often organometallic, compounds. The organotin(lV) compounds that were first tested were those that were available or easily synthesized, like tri- or diorganotin(rV) halides. 

Table 11 Antitumor activities of organotin(IV) compounds against two types of leukemia cell lines...

Finally, more and more experimental data must be collected in order to understand the biological (including antitumor) activity of organotin(IV) complexes... 

Photoelectron spectra and ab initio calculations correlated for Me3ES2P(OR)2 (E = Si, Ge, Sn).104 Some organotin and organoantimony dithiophosphates (and -phosphinates) have been found to possess antitumor activity.105,106... 

The compounds having not only nitrogen but also oxygen or sulfur as coordination atoms also show antitumor activity [103]. The activity (T/C) of organotin compounds is about 200% lower than those of the platinum derivatives (200-300%) against the same tumor system, as organotin compounds do not show nephrotoxicities. Sn is expected to show lower side effects. 

Antitumor in vitro activiry of many organotin derivatives have been well doeumented [296-298], A number of organotin derivatives of earboranes were synthesized and antitumor activity of some of them was determined (Figure 27) [299-303],... 

In the evaluation of a number of studies, Saxena and Huber found that the most active organotin species were the dialkyltin compounds. Brown found that triphenyltin acetate exhibited antitumor activity in mice, while triphenyltin chloride was inactive. She believed that the degree of water solubility was an important factor in the anticancer activity of the organotin compounds. 

In contrast to this view, but in analogy with the behavior of several antitumor metal complexes, some authors proposed that the DNA is the probable target for cytotoxic activity of organotin(IV) compounds. In this section we survey and compare the most important literature data published to date on this subject. 

Attempts to improve the bioavailability of the organotin(IV) cations by the formation of water-soluble complexes or by their inclusion into )S-cyclodex-trin have also been reported. In spite of their widespread activity, these antitumor organotin(IV) complexes have not yet been subjected to extensive clinical trials in humans. 

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