Skip to main content
. Author manuscript; available in PMC: 2013 Nov 1.
Published in final edited form as: Anal Biochem. 2012 Jul 31;430(1):4–15. doi: 10.1016/j.ab.2012.07.022

Table 1.

Electron ionization mass spectra of native non-derivatized unlabeled AECK-DD and 13C2-AECK-DDa

m/z (intensity, %) Ion assignment m/z (intensity, %) Ion assignment
AECK-DD 13C2-AECK-DD
228 (100) M+• 230 (100) M+•
200 (36) [M–CO]+ • 202 (39) [M–CO]+ •
154 (58) [M–SCH2CH2N]+ • and [M–CH2CH2SCH2]+ • 156 (29)
155 (77)		 [M–SCH2CH2N]+ •
[M–CH2CH2S13CH2]+ •
126 (21) [M–SCH2CH2N–CO]+ • and [M–CH2CH2SCH2–CO]+ • 128 (20)
127 (41)		 [M–SCH2CH2NCH2–CO]+•
[M–CH2CH2S13CH2–CO]+ •
99 (17) [CH2CH2SCHCN]+• 100 (26) [CH2CH2S13CHCN]+ •
71 (17) [SCHCN]+ • 72 (15) [S13CHCN]+ •
45 (17) [SCH]+ • 46 (23) [SCH]+ •
28 (15) [CO]+ • and/or [CH2CH2]+• 28 (16) [CO]+ • and/or [CH2CH2]+•
a

Only ions with an intensity of ≥ 15% relative to M+• are listed.