TY - JOUR
AU1 - Zhang, Yufeng
AU2 - Zhang, Peng
AU3 - Cheng, Yiyu
AB - Eighteen isoprenylated flavonoids (8 flavanones, 3 flavanols, and 7 chalcones) isolated from Kushen or synthesized were studied by positive and negative ion electrospray ionization multistage tandem mass spectrometry (ESI‐MSn). Plausible fragmentation patterns were obtained by comparing their MSn spectra with each other, which were further supported by high‐resolution MS data and two model compounds. It was shown that the 2′‐OH group would make the C‐ring of flavonoids studied more labile through a six‐membered mechanism, resulting in base peaks of 1, 3A+ (positive mode) and 1, 4A− (negative mode). In addition, the 2′‐OH is also responsible for the neutral loss of water in (+)ESI/MS2 of flavanones. The neutral loss of water (or methanol) in (−)ESI/MS2 of flavanols was elucidated by a E2 elimination mechanism. Different relative abundances (RA) of 1, 3A+ and S+ in (+)ESI/MS2 spectra were used to discriminate flavanones with their open‐ring products, chalcones, since the equilibrium for flavanone$\leftrightarrow$chalcone isomerization in ESI ion source could not be obtained in positive mode. Copyright © 2008 John Wiley & Sons, Ltd.
TI - Structural characterization of isoprenylated flavonoids from Kushen by electrospray ionization multistage tandem mass spectrometry
JF - Journal of Mass Spectrometry (Incorp Biological Mass Spectrometry)
DO - 10.1002/jms.1423
DA - 2008-10-01
UR - https://www.deepdyve.com/lp/wiley/structural-characterization-of-isoprenylated-flavonoids-from-kushen-by-D3mVxhqtfn
SP - 1421
EP - 1431
VL - 43
IS - 10
DP - DeepDyve
ER -