Phenolic compounds with pancreatic lipase inhibitory activity from Korean yam (Dioscorea opposita)

Figures & data

Figure 1. Effect of D. opposita on pancreatic lipase in the presence or absence of samples at the final concentration of 10 µg/mL. Inhibition of lipase by 95% EtOH extract and fractions of D. opposita (A) and the subfractions of D. opposita n-BuOH fraction (B). Each values are expressed as the % control means ± SD of triplicate experiments; *p < 0.05, **p < 0.01 and ***p < 0.001 compared with the control.

Figure 2. Structures of phenolic compounds isolated from D. opposita n-BuOH extract.

Figure 3. A dose-dependent inhibition of lipase activity by 3,3′,5-trihydroxy-2′-methoxybibenzyl (A), (4E,6E)-1,7-bis(4-hydroxyphenyl)-4,6-heptadien-3-one (B) and Orlistat (C). Values are means of triplicate assays ± standard error.

Table 1. Inhibitory effects of compounds isolated from D. opposita against porcine pancreatic lipase†.

Compounds	Ki‡ (µm)	IC50§ (µm)
1	2.75 ± 0.14	13.50 ± 0.65**
2	6.45 ± 1.32	29.20 ± 6.26**
3	1.82 ± 0.43	8.77 ± 2.03*
4	6.79 ± 0.40	32.32 ± 1.91***
5	6.28 ± 0.68	30.14 ± 3.25***
6	5.06 ± 0.24	25.36 ± 1.14**
7	9.28 ± 0.26	44.11 ± 1.23***
10	9.66 ± 0.45	45.70 ± 2.14***
11	2.67 ± 0.30	12.72 ± 1.41*
13	8.57 ± 0.41	40.61 ± 1.93***
14	4.96 ± 1.34	25.09 ± 6.35**
17	7.49 ± 0.77	34.81 ± 3.64***
19	3.34 ± 0.86	16.36 ± 4.07*
20	1.92 ± 0.16	9.12 ± 0.76*
21	2.17 ± 0.74	11.08 ± 3.50*
Orlistat¶	0.26 ± 0.01	1.24 ± 0.05

†Compounds 8, 9, 12, 15, 16, 18, 22 and 23 were considered to be inactive

‡The K_i values were calculated from Cheng–Prusoff equation and K_m constant was determined using the Lineweaver–Burk plot.

§Each values were expressed as the means ± SD of triplicate experiments.

¶Positive control.

*p < 0.05, **p < 0.01 and ***p < 0.001 compared with the control.