**3. Conclusion**

448 Biochemistry

**measured Stobadine Trolox** 

IC50 (µmol/L) 25.3 ± 14.6 93.5 ± 8.5

IC50 (mol/L) 0.65 ± 0.08 0.13 ± 0.02

8.1 ± 0.5 (0.25 mmol/L)

7.9 ± 0.7 (0.25 mmol/L)

3.4 ± 0.5 (0.25 mmol/L)

IC50 (µmol/L) 35 98

121 ± 15 79 ± 8

44 ± 8 131 ± 20

7.4 ± 0.7 (0.25 mmol/L)

6.5 ± 0.4 (0.25 mmol/L)

3.3 ± 0.2 (0.25 mmol/L)

1.5 0.38

**Assay system Parameter** 

precipitation IC50 (µmol/L)

Amadori product (with respect to 8.2 ± 0.4 nmol/mg BSA for control without

fluorescence (with respect to 11.2 ± 0.7 nmol/mg BSA for control without inhibitor)

Carbonyl groups (with respect to 5.6 ± 0.4 nmol/mg BSA for control without

(The increase in lag time given by one stobadine molecule per single LDL particle)

inhibitor)

∆tlag (min)

inhibitor)

Relative

Inhibition of protein

Inhibition of protein oxidation

Glucose attachment into the molecule of BSA

Glycationinduced fluorescence changes of BSA

Formation of DNPH-reactive carbonyl groups in BSA

Inhibition of TBARS production

Cu2+-mediated oxidation of LDL

(Horakova et al., 1996)

Fe2+/ascorbate induced oxidative damage of rat

brain homogenate (Horakova et al.,

2000)

AAPH induced LPO in DOPC

(Rackova et al., 2002)

AAPH-induced oxidative modification of soluble eye lens proteins

(Stefek et al., 2005)

Oxidative modification of BSA in an experimental glycation model (Stefek et al., 1999)

BSA cross-linking induced Fe2+/EDTA/H2O2/ascorbate (Kyselova et al., 2003)

liposomes

On balance then, the present paper, by summarizing the current data on both trolox and stobadine, underscores the structural and physicochemical differences between the two compounds as respective representatives of phenolic- and indole-type antioxidants. The structural variance explains their different mechanisms of antioxidant action and variable efficacies in the range of assay systems studied. Considering a plethora of studies reported on stobadine antioxidant action, physicochemical properties, and on a variety of its other biological activities, stobadine may represent a pertinent indole-type reference antioxidant. Hence, in studies of indole compounds, stobadine antioxidant standard may be utilized as a more relevant alternative to structurally diverse trolox.
