1: With hesperidinase H8137 T=40°C; pH=3.8; 15 h; aq. acetate bufferEnzymatic reaction; 2: With pyridine; (L)-cysteine methyl ester hydrochloride T=60°C; 1 h; 3: With N,O-bis(trimethylsilyl) trifluoroacetamide T=60°C; 1 h;