The pentacyclic triterpenoids in herbal medicines and their pharmacological activities in diabetes and diabetic complications - Alqahtani, A; Hamid, K; Kam, A; Wong, K H; Abdelhak, Z; Razmovski-Naumovski, V; Chan, K; Li, K M; Groundwater, P W; Li, G Q (Curr Med Chem, 2013)