Table 2 Characterization of major ingredients in Huang-Qin extract by HPLC–DAD–APCI–MS

1

14.0

215, 275, 318

APCI⁺—MS: 549(100); MS² [549]: 531(70), 513(60), 495(90), 483(20), 465(45), 429(10), 411(100), 393(30), 363(10); MS³ [411]: 393(100), 375(60), 363(70), 333(80), 309(30), 279(28)

APCI⁻—MS: 547(100); MS² [547]: 529(20), 511(10), 487(85), 457(100), 427(42), 409(10), 367(60), 337(70); MS³ [457]: 367(10), 337(100)

Chrysin-6-C-arabinosyl-8-C-glucoside^c

2

17.6

215, 275, 318

APCI⁺—MS: 549(100); MS² [549]: 531(100), 513(30), 495(20), 483(45), 465(20), 453(18), 441(18), 411(10), 393(8), 381(6); MS³ [531]: 513(80), 495(60), 483(100), 465(75), 453(70), 441(60), 411(12), 393(30), 381(50), 363(40)

APCI⁻—MS: 547(100); MS² [547]: 529(15), 487(15), 457(70), 427(100), 367(20), 337(30); MS³ [427]: 367(15), 337(100)

Chrysin-6-C-glucosyl-8-C-arabinoside^c

3

27.3

215, 277, 316

APCI⁺—MS: 447(100), 271(20); MS² [447]: 271(100); MS³ [271]: 253(40), 241(100)

APCI⁻—MS: 559(100); MS² [559]: 445(100); MS³ [445]: 269(100)

Baicalin^b

4

29.7

215, 280, 360

APCI⁺—MS: 447(100), 271(20); MS² [447]: 271(100)

APCI⁻—MS: 559(20), 445(100); MS² [559]: 445(100); MS³ [445]: 269(100)

Norwogonin-7-O-glucuronide^c

5

30.8

215, 273, 312

APCI⁺ – MS: 431(100), 255(20); MS² [431]: 255(100)

APCI⁻—MS: 543(100); MS² [543]: 429(100); MS³ [429]: 253(100), 173(40)

Chrysin-7-O-glucuronide^c

6

32.3

215, 275, 349

APCI⁺—MS: 461(100); MS² [461]: 285(100); MS³ [285]: 270(100)

APCI⁻—MS: 573(100); MS² [573]: 459(100); MS³ [459]: 283(100), 268(20), 174(30)

Wogonoside^b

7

40.1

215, 275, 322

APCI⁺—MS: 271(100); MS² [271]: 241(100)

Baicalein^b

8

48.0

210, 275

APCI⁺—MS: 285(100); MS² [285]: 270(100)

Wogonin^b

9

50.5

215, 273, 318

APCI⁺—MS: 285(100); MS² [285]: 270(100)

Oroxylin A^c