Objective: To study the liver protecting chemical constituents of Caesalpinia minax. Method: The compounds were isolated and purified by silica gel columns

and recrystallization

and the structures of these compounds were identified by MS and NMR. Result: A total of 16 kinds of compounds were obtained.They were identified as caffeine(1)

β-sitosterol(2)

octadecanoic acid(3)

ursolic acid(4)

oleanolic acid(5)

β-daucosterol(6)

3

5

7-3-hydroxy-4'-methoxy dihydroflavonol(7)

neocaesalpin L(8)

neocaesalpin L1(9)

neocaesalpin K(10)

minaxin C(11)

ferulic acid(12)

caffeic acid(13)

gallic acid(14)

12α-ethoxyl-1α

6α

7β-triacetoxy-5α

14β-dihydroxy-cass-13(15)-en-16

12-olide (15) and stigmasta-5

22(E)-dien-3-beta-ol(16). Conclusions: Compound 5

6

7

12

13

16 were isolated from C. minax for the first time

and compound 7 was first obtained from the Leguminosae.