Objective:To compare inhibition effect of four neoflavonoids on respiratory burst of rat neutrophils. Method: Vc as reference

chemi-luminescence was used to compare strengths of the four neoflavonoids compounds in antineutrophill rspiratory burst. Result: Four neoflavonoids have different effect on neutrophils respiratory burst

and the marked logarithmic relationship existed between bioactivity and chemical structure. The inhibition abilities of four neoflavonoids on neutrophils respiratory burst were as follows: 2

4-dihydroxy-5-methoxy-benzophenone

R(+)-dalbergiphenol

R(-)-latifolin

2-O-methyllatifolin. Conclusion: In chemical structure of neoflavonoids

the Cross-Shaped conjugation of A ring was favorable for the inhibition effect of four neoflavonoids on neutrophils respiratory burst

and the phenolic hydroxyl group

in A ring

was the key bioactivity group. In addition

the hydroxymethylation of hydroxyl in B ring was not favorable for improving bioactivity.