The utilization of platinum complexes in medicine continues to be a prevalent treatment modality for diverse tumour types. However, it should be noted that certain platinum complexes are characterized by a high degree of toxicity. In recent years, there has been a focus among scientists on synthesizing “non-classic” platinum complexes, such as those with a trans-configuration, Pt(IV) complexes, and mixed ammine/amine platinum complexes, with the aim of reducing the toxic side effects of certain platinum complexes, including cisplatin. For instance, newly synthesized platinum complexes with a trans-configuration exhibited substantial cytotoxic activity which was comparable to that of the corresponding cis-isomers and cisplatin. This finding challenged the prevailing cis-geometry paradigm and prompted a re-evaluation of the structural activity relationships (SARs) of antitumour platinum complexes. It is widely accepted that Pt(IV) complexes act as prodrugs and release the active Pt(II) species. This property renders them promising candidates as anticancer drugs. Furthermore, it has been established that mixed ammine/amine platinum complexes are less toxic than cisplatin. In addition, compared to cisplatin, they have been observed to have equivalent or greater cytotoxic activity.

The antioxidant activity of bioactive compounds is fundamentally determined by their chemical structures and, more specifically, by the nature and positioning of key functional groups. Despite the structural diversity among natural and synthetic antioxidants, many share common molecular features that enable them to neutralize reactive oxygen and nitrogen species. The present review is an attempt to systematize the classification of antioxidants according to their functional groups. The role of redox-active moieties such as phenolic hydroxyl (-OH), thiol (-SH), amine (-NH2), and carbonyl (C=O) groups is also highlighted. The groups facilitate electron or hydrogen donation, stabilizing free radicals and interrupting oxidative chain reactions. Conjugated π-systems, such as those found in carotenoids and polyphenols, further enhance antioxidant capacity by allowing electron delocalization across the molecule. By examining the structural basis of antioxidant mechanisms, the review underscores the critical relationship between molecular structure and biological function in oxidative stress mitigation.