. 2021 Sep 18;26(18):5673. doi: 10.3390/molecules26185673

Table 9.

Summary of structures and inhibitory activities of flavonoids against three sialyltransferases (Data from [166]).

#	Functional Groups on the Flavonoid Core Structure											IC₅₀ (μM)
#	C3	C4	C5	C6	C7	C8	C2′	C3′	C4′	C5′	C6′	rST6	hST6	rST3
71	H	=O	OH	H	OCH₃	H	H	H	OH	H	H	39.0 ^A	39.0 ^A	39.0 ^A
72	O-β-D-Glc	=O	OH	H	OH	H	H	H	OH	H	H	43.5 ^A	-	-
73	H	=O	OH	H	O-β-L-Glc	H	H	H	OH	H	H	25.0 ^A	40.0 ^A
74	H	=O	OH	β-D-Glc	OCH₃	H	H	H	OH	H	H	32.9% ^B	49.8% ^B	10.7 ^B
75	H	=O	OH	H	OC₂H₅	H	H	H	OH	H	H	93.5 ^A	NT	NT
76	H	=O	H	H	H	H	H	H	OH	H	H	66.0 ^A	81.7 ^A	192.2 ^A
77	H	=O	H	H	H	H	H	OH	OH	OH	H	5.1 ^A	7.1 ^A	1.4 ^A
78	OH	=O	H	H	H	H	H	H	OH	H	H	424 ^A	-	NT
79	OH	=O	H	H	H	H	H	OH	OH	OH	H	1.9 ^A	7.3 ^A	NT

rST6, hST6 and rST3 indicate ratST6Gal-I, human ST6Gal-I and rat ST3Gal-III, respectively. Glc, glucose. -, not inhibited significantly up to 50 μM compounds; NT, not tested. ^A IC₅₀ values of compounds at 15 mM and 250 μM CMP-Neu5Ac for ST6Gal-I and ST3Gall-III, respectively. ^B Relative infectivity in the presence of compounds (50 μM) to control infection.