Crystal Structure and Antioxidant Activity of 6-Gingerol Oxime

Abstract

Under the acidic condition, 6-gingerol (C17H26O4) reacted with hydroxylamine to generate 6-gingerol oxime (C17H27NO4). Single-crystal X-ray diffraction with CuKα radiation (λ = 1.54184 Å) revealed the crystal belongs to the orthorhombic system, the space ground is P212121 with a = 5.24240(10), b = 25.7792(4), c = 25.9824(5) Å, V = 3511.39(11) Å3, Z = 8, Mr = 309.40, Dc = 1.171mg/mm3, μ = 0.669mm-1, S = 1.035, F(000) = 1344.0, the final wR2 was 0.1132 (all data) and R1 was 0.0412 [I>2σ (I)]. Two molecules compose one monomeric unit in the crystal. And the hydrogen bonds construct the dimer and the integral crystal spacial structure. The antioxidant activity of the 6-gingerol oxime was tested by the scavenging effect on DPPH radical and potassium ferricyanide reducing power test while Vitamin C was regarded as the comparison. The IC50 of the oxime for the scavenging effect on DPPH was 0.0471 g/L which was less strong than Vitamin C. The reducing power of Vitamin C was about three times powerful than the 6-gingerol oxime.