Novel Xanthine Oxidase (XO) inhibitory phenylindanes produced by thermal reaction of caffeic acid

Figures & data

Figure 1. Panel A, XO inhibitory activity of thermal reaction products (0.3 mg/mL) from chlorogenic acid, caffeic acid and quinic acid at 200^ºC. Scale of X-axis expresses reaction time. Data are expressed at the mean ± SD (n = 3). Panel B, XO inhibitory activity of thermal reaction product (0.3 mg/mL) from caffeic acid at the different temperatures. Scale of X-axis expresses reaction time. Data are expressed at the mean  ± SD (n = 3).

Figure 2. Structures of identified phenylindanes from the thermal reaction of caffeic acid.

Table 1. XO inhibitory activity of identified phenylindanes (200 μmol/L) from thermal reaction product of caffeic acid.

compound	% inhibition (mean± SD, n = 3)
1	61.9 ± 0.6
2	47.0 ± 0.6
3	18.8 ± 3.5
4	20.4 ± 2.6
5	25.5 ± 2.3
6	35.5 ± 2.6
Caffeic acid	4.0 ± 2.2
Allopurinol (0.5 μmol/mL)^a	51.9 ± 1.8

^a0.5 μmol/mL of allopurinol was employed as positive control.