Three New 24‐Noroleanane Triterpenoids from Quercus aliena var. acuteserrata

Three new 24‐noroleanane triterpenoids, i.e., 2α,19α‐dihydroxy‐3‐oxo‐24‐norolean‐12‐en‐28‐oic acid ( 1 ) and 19α‐hydroxy‐3‐oxo‐24‐norolean‐12‐en‐28‐oic acid ( 2 ), and 2α,3β,19α‐trihydroxy‐24‐norolean‐12‐en‐28‐oic acid ( 3 ) were isolated from Quercus aliena var. acuteserrata, together with three known compounds, bartogenic acid ( 4 ), ilexgenin A ( 5 ), and aophitolic acid ( 6 ). Their structures were established by spectroscopic methods, especially 2D‐NMR and MS analyses.