Table II.

The substrate specificity of UGT74M1

UGT74M1 assays were performed as described in “Materials and Methods” using the radiochemical assay. The substrates for which no activity was detected are α-amyrin, β-amyrin, asiatic acid, benzoic acid, caffeic acid, cholesterol, cyanidin, diosgenin, erythrodiol, lupeol, oleanolic acid, quercetin, salicylic acid, and spinasterol.

SubstrateRelative ActivityC-23C-16
%
16α-Hydroxygypsogenic acid177COOHOH
Gypsogenic acid100COOHH
Gypsogenin22CHOH
Quillaic acid19CHOOH
Echinocystic acid9CH3OH
Hederagenin4.5CH2OHH
Betulinic acid2.5CH3H