Biological activity unrelated to structure

It has been known for some time that vitamin E can act as an antioxidant within the body [21, 61] and that the biological potency of the tocopherols is proportional to their antioxidant activity [62], Synthetic antioxidants, which often have structures unrelated to that of the vitamin, are also capable of preventing the symptoms of vitamin E deficiency [23, 24, 63, 64]. The general proposal [63, 65], therefore, is that the function of vitamin E is one of an in vivo antioxidant, protecting membrane phospholipids from attack by free radicals generated within the cell. 

Additionally, in the case of validated hits with records of any previously known biological activity, the SAR expansion shall include other small molecules annotated with the same primary target, yet belonging to structurally unrelated scaffolds. When possible, it is also useful to investigate whether it is possible to rescue or compete away the phenotypic effect by adding a small molecule, naturally occurring or synthetic, that has the opposite MMoA on the primary target. 

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