Antioxidant potential of anthrarobin (1,2,10 trihydroxy anthracene) and its acyl derivatives

The current study explores the antioxidant potential of anthrarobin and its synthesized derivatives determined by various methods including dpph radical scavenging ability,reducing power and superoxide scavenging activity. anthrarobin was acetylated with acetic anhydride in the presence of pyridine to afford anthracen-1,10-dihydroxy-2-acetate (1),anthracen-1-hydroxy-2,10-diacetate (2) and anthracen-1,2,10-triacetate (3). anthrarobin exhibited good antioxidant potential with 68 and 78% at 50 μm and 100 μm concentrations,respectively. reducing power of anthrarobin increases with increase in concentration in a dose-dependent manner as could be seen from 37 and 54% activity at the concentration of 50 and 100 μm,respectively. 3-tetra-butyl-4-hydroxyanisole (bha) used as standard showed 84 and 93% activities at 50 and 100 μm,respectively. bha and anthrarobin were compared to determine that how much superoxide radicals were scavenged in alkaline dmso by different concentrations. it was found that 50 μm of anthrarobin was needed to scavenge 50% radicals while 12.5 μm of bha scavenged 50% radicals in dmso. it is concluded that anthrarobin has highest antioxidant potential as compared to its derivatives. it is postulated that position and numbers of hydroxyl group in anthrarobin are responsible for antioxidant potential and the activity decreases with the substitution of acyl groups at various positions in synthesized derivatives.