Analysis of MS/MS fragmentation of taxoids.
The fragmentation pathways of seven types of taxoids were investigated by using a LC-MS/MS method, namely: (1) neutral taxoids with a C-4(20) double bond; (2) taxoids with a C-4(20) double bond and oxygenation at C-14; (3) 5-cinnamoyl taxoids with a C-4(20) double bond; (4) a basic taxoid with a C-4(20) double bond; (5) a taxoid with a C-4(20) epoxide; (6) taxoids with an oxetane ring; and (7) taxoids with an oxetane ring and a phenylisoserine C-13 side chain. Depending on the class of core structure and the substitution pattern, each taxoid gave either the molecular adduct ion [M+NH4]+ or [M+H]+. In the MS/MS, the molecular adduct ion gave characteristic product ions corresponding to the loss of water, acetic acid, benzoic acid, and cinnamic acid or the phenylisoserine group. These could reflect the difference of the substitutions and structural modifications and should be utilized for the structure elucidation oftaxoids by LC-MS.
Division of Complementary Medicine, School of Allied Health Science, Kitasato University, 1-15-1 Kitasato, Sagamihara 228-8555, Japan.
Kouhei
K
Morikawa
Ken
K
Tanaka
Feng
F
Li
Suresh
S
Awale
Yasuhiro
Y
Tezuka
Takahiro
T
Nobukawa
Shigetoshi
S
Kadota
D002853:Chromatography, Liquid; D021241:Spectrometry, Mass, Electrospray Ionization; D053719:Tandem Mass Spectrometry; D043823:Taxoids / Q000737:chemistry* / Q000302:isolation & purification
D043823:Taxoids