Isolation and Structure-Activity Relationship of the Antioxidant Chemical Constituents from the Flowers of Rosa chinensis Jacq

Figures & data

Table 1  Application of sample

Number	Method
Ac	2 ml DPPH·ethanol solution + 1 ml Tris-HCl + 2 ml methanol
Ai	2 ml DPPH·ethanol solution + 1 ml Tris-HCl + 2 ml sample solution
Aj	2 ml dehydrated alcohol + 1 ml Tris-HCl + 2 ml sample solution
A0	2 ml dehydrated alcohol + 1 ml Tris-HCl + 2 ml methanol

Table 2  The DPPH scavenging activities of the extracts of the flowers of Rosa chinensis Jacq

Group	IC50 (μg/ml)
Petroleum ether fraction	92.27 ± 1.40
Chloroform fraction	49.38 ± 0.91
Ethyl acetate fraction	10.14 ± 0.18
n-Butanol fraction	23.86 ± 0.51
Water-soluble fraction	32.61 ± 0.67
Ethanol fraction	33.84 ± 0.97
Ascorbic acid	6.89 ± 0.30

Figure 1 Ten compounds were obtained from ethyl acetate fraction.

Table 3  Free radical-scavenging activity (IC₅₀) of the isolated ten compounds of the flowers of Rosa chinensis Jacq

Compound	IC50 (mM)
3,4,8,9,10-Pentahydroxydibenzo[b,d]pyran-6-one (1)	0.015 ± 0.001
Quercetin (2)	0.039 ± 0.001
Kaempferol (3)	0.051 ± 0.002
3,5,7,4′-Tetra-hydroxy-8-methoxy-flavone (4)	0.054 ± 0.001
Isoquercetrin (5)	0.030 ± 0.001
Kampferol 3-O-β-D-glucoside (6)	0.042 ± 0.001
Tiliroside (7)	0.045 ± 0.002
Kampferol 3-O-(6′′-galloyl)-β-D-glucoside (8)	0.016 ± 0.000
Kampferol 3-O-(2′′,6′′-digalloyl)-β-D-glucoside (9)	0.013 ± 0.001
Quercetin 3-O-(2′′,6′′-digalloyl)-β-D-glucoside (10)	0.010 ± 0.001
Ascorbic acid	0.039 ± 0.002