Table 3.

Effect of polyphenolic compounds [cyanidin, quercetin, silybin, cyanin, (+)-catechin and (−)-epicatechin] on kinetic parameters of chromogenic substrate hydrolysis by thrombin

	K m (10−6 M)	V max (10−6 mol/min)	k cat (1/s)
Control	158.7	30.7	29.1
Cyanidin	600.6	30.3	28.7
Quercetin	633.8	29.4	27.8
Silybin	550.5	27	25.6
Cyanin	344.6	20.8	19.7
(+)-Catechin	700.1	31.2	29.5
(−)-Epicatechin	481.5	29.4	27.8

Parameters: Michaelis constant (K _m) and maximum speed (V _max) of reaction was obtained from Lineweaver–Burk curves; enzyme catalytic constant (k _cat) was calculated from formula: k _cat = V _max/E ₀