In vitro effects of some flavonoids and phenolic acids on human pyruvate kinase isoenzyme M2

Figures & data

Figure 1. Activity (%) versus polyphenols concentrations regression analysis graphs for PKM2 in the presence of some polyphenols.

Figure 2. The Lineweaver–Burk graph using three different taxifolin concentrations for determination of K_i.

Figure 3. The Lineweaver–Burk graph using three different neoeriocitrin concentrations for determination of K_i.

Table 1. PKM2 inhibition or activation data by some polyphenol compounds.

Compounds class	Compounds name	IC50/AC50 µM	Effect
Flavonols	1. Fisetin	0.90	Inhibition
	2. Rutin	7.80	Inhibition
	3. Galangin	8.27	Inhibition
	4. Quercetin	9.24	Inhibition
	5. Kaempferol	9.88	Inhibition
	6. Morin hydrate	37.20	Inhibition
	7. Myricetin	0.51	Activation
	8. Quercetin 3-β-d-glucoside	1.34	Activation
	9. Quercetin 3-d-galactoside	27–107 µM	Ineffective
Flavanons	10. Neoeriocitrin	0.65	Inhibition
	11. Neohesperidin	14.20	Inhibition
	12. Naringin	16.60	Inhibition
	13. Hesperidin	17.30	Inhibition
	14. Hesperitin	29.10	Inhibition
	15. Naringenin	70.80	Activation
Flavanonols	16. (−)-Catechin gallate	0.85	Inhibition
	17. (±)-Taxifolin	1.16	Inhibition
	18. (−)-Epicatechin	1.33	Inhibition
	19. (+)-Gallocatechin	4–16 µM	Ineffective
Phenolic  acids	20. Ferulic	11.4	Inhibition
	21. Syringic and	13.8	Inhibition
	22. Caffeic acid	36.3	Inhibition
	23. 3,4-Dihydroxybenzoic acid	78.7	Inhibition
	24. Gallic acid	332.6	Inhibition
	25. Shikimic acid	990	Inhibition
	26. p-Coumaric acid	22.2	Activation
	27. Sinapinic acids	26.2	Activation
	28. Vanillic	607.9	Activation

Table 2. K_i values obtained from the Lineweaver–Burk graphs for PKM2 in the presence of three fixed inhibitors and five substrate concentrations for different polyphenol compounds.

Compounds	Inhibition type	Ki constant µM
Taxifolin	Competitive	0.84 ± 0.25
Neoeriocitrin	Non-competitive	1.99 ± 1.14
Fisetin	Non-competitive	3.69 ± 1.89
(−)-Catechin gallate	Non-competitive	2.60 ± 1.89
(−)-Epicatechin	Non-competitive	4.07 ± 2.27