Fig. 7
Replacement of the steviol aglycone ring of the substrate by another hydrophobic group. a Direct MS of the reaction of 4-nitrophenyl β-D-glucopyranoside by UGT76G1. The nitrophenyl ring shows a similar role to give the reactivity to the glycone unit. The reaction of 4-nitrophenyl β-d-glucopyranoside was catalyzed by 0.25 mg ml−1 UGT76G1 for 12 h. The two main negative ions derived from the substrate (M) and product (P) are labeled. b The slow reaction scheme and the binding mode of 4-nitrophenyl β-D-glucopyranoside by UGT76G1
