Objective: To assess difference of fingerprints and index constituents in couplet medicines of Lonicerae Similis Flos-Scutellariae Radix before and after compatibility.Method: The separation was performed on InertSustain C18 column(4.6 mm×250 mm

5 μm) with mobile phase composed of acetonitrile-0.2% phosphoric acid solution for gradient elution at the flow rate of 1.0 mL · min-1

the column temperature was set at 25℃

the injection volume was 10 μL

the detection wavelengths were set at 327 nm(0-27

43-62 min)

237 nm(27-33 min)

274 nm(33-43

90-120 min)

280 nm(62-90 min).The fingerprints of single and mixed decoction of 10 batches of Lonicerae Similis Flos and Scutellariae Radix were established

common peaks were demarcated and their respective control fingerprints were gained.Attributing analysis of common peaks in the fingerprints after compatibility was adopted and the contents of index ingredients through the 11 kinds of mixed control were determined.Result: Twenty-six common peaks were marked in the HPLC fingerprints of couplet medicines;9 derived from Lonicerae Similis Flos and 17 derived from Scutellariae Radix;the peaks of 1

2

3

4

13

14

15

18

23

25

26 corresponded to neochlorogenic acid

chlorogenic acid

cryptochlorogenic acid

caffeic acid

isochlorogenic acid B

isochlorogenic acid A

isochlorogenic acid C

baicalin

wogonoside

baicalein

wogonin

respectively.The number of peaks had no change before and after compatibility

but the contents of index ingredients made differences.Conclusion: There are no differences in chemical ingredients from couplet medicines of Lonicerae Similis Flos-Scutellariae Radix before and after compatibility

but the dissolution of main effective components affects each other.