Table 1. β-Glucosidases with Relaxed Substrate Specificities toward Flavonoid β-d-Glucosides.
| GH family | enzyme(s) | speciesa | flavonoid glucoside substrateb | relative activity [%] | remarks | ref |
|---|---|---|---|---|---|---|
| – | – | Citrus sinensis (p) | hesperetin 7-O-linked | 199c | main enzymatic activity toward the disaccharides cellobiose, laminaribiose and gentiobiose | (155) |
| naringenin 7-O-linked | 138c | |||||
| – | GII | Penicillium decumbens | daidzein 7-O-linked (1.6) | 1c | in addition, hydrolysis activity toward cellobiose and gentiobiose | (156) |
| apigenin 7-O-linked (1.5) | 1c | |||||
| GH1 | Bbg572 | Bifidobacterium lactis | daidzein 7-O-linked | – | activity toward isoflavanones, quercetin glucosides, and glucosyl-based disaccharides with β-1→2, β-1→3, β-1→4, and β-1→6 glycosidic bonds; hydrolysis products were identified by TLC | (157) |
| genistein 7-O-linked | ||||||
| glycitein 7-O-linked | ||||||
| quercetin 3-O-linked | ||||||
| quercetin 4′-O-linked | ||||||
| quercetin 7-O-linked | ||||||
| GH1 | Llbglu1 | Leucaena leucocephala (p; legume family) | genistein 7-O-linked | – | – | (158) |
| naringenin 7-O-linked | ||||||
| apigenin 7-O-linked | ||||||
| genistein 4′-O-linked | ||||||
| GH1 | NfBGL595 wild-type enzyme | Neosartorya fischeri | apigenin 7-O-linked (747) | 2b | – | (107) |
| genistein 7-O-linked (1670) | 5b | |||||
| quercetin 3-O-linked (759) | 2b | |||||
| GH1 | TnBgl1A wild-type enzyme | Thermotoga neapolitana | daidzein 7-O-linked | 100 | a mutagenesis study was performed based on the crystal structure of TnBgl1A (PDB 5IDI; see text) | (106) |
| genistein 7-O-linked | 100 | |||||
| kaempferol 7-O-linked | 100 | |||||
| quercetin 4′-O-linked | 100 | |||||
| quercetin 3,4′-O-diglucoside | 82 | |||||
| quercetin 3-O-linked (101) | 73 (5c) | |||||
| kaempferol 3-O-linked | 87 | |||||
| isorhamnetin 3-O-linked | 93 | |||||
| GH1 | – | Thermobifida fusca | daidzein 7-O-linked | 100 | in addition, activity toward cellobiose and cyanidin 3-O-β-d-glucoside | (159) |
| genistein 7-O-linked | 62 | |||||
| GH3 | SBGL | Novosphingobium sp. | daidzein 7-O-linked (33300) | – | in addition, hydrolysis activity toward cellobiose, gentiobiose, and amygdalin | (126) |
| genistein 7-O-linked (19200) | ||||||
| GH3 | GluDHis and GluEHis | Bifidobacterium pseudocatenulatum | genistein 7-O-linked | – | in addition, hydrolysis activity toward cellobiose and gentiobiose; hydrolysis products were identified by TLC | (160) |
| daidzein 7-O-linked | ||||||
| GH5 | EXG1, SPR1 and YIR007W | Saccharomyces cerevisiae | daidzein 7-O-linked | – | EXG1: PDB 1H4P | (161) |
| genistein 7-O-linked | ||||||
| naringenin 7-O-linked | ||||||
| kaempferol 7-O-linked | ||||||
| luteolin 7-O- and 4′-O-linked | ||||||
| quercetin 4′-O-linked | ||||||
a
(p): plant.
b
Where available, the corresponding kcat/KM values [s–1 mM–1] are indicated in parentheses.
c
Relative to the activity toward pNP β-d-glucopyranoside (100%).