Post on 26-Mar-2015
transcript
Electrochemistry upfront MS
1
ROXY™ - EC/LC upfront MS
With ReactorCell™ forGenerating Redox metabolitesCleavage of proteins/peptidesSignal enhancement in MSOxidative stressMetabolism
2
Why Electrochemistry / MS?
Mimics Natures Redox Reactions
In Drug Development and Proteomics
Fast & CleanComplementary to existing methods
3
Why Electrochemistry / MS?
Mimics Natures Redox Reactions
Drug developmentImmediate results, minutes vs weeks
No by products, no cleanupNo biohazardNo rodents
ProteomicsNo enzymes, clean without by products
4
Electrochemistry / MS
Mimicking nature’s redox reactionsFast alternative for laborious, time consuming procedures
5
Electrochemistry / MS
Mimicking nature’s redox reactionsFast alternative for laborious, time consuming procedures
6
MSEC
Modes of operation
On-line EC/MS
On-line EC/LC/MS
- Pre injection
- Post column
Off-line EC/MS
7
Electrochemical Reaction
8
ΔE
Facilitates the EC reaction
9
Role of electrode potential E
0
20
40
60
80
100
0 400 800 1200 1600
E (mV)
Sig
nal
(%
)
no reaction
formation of oxidation or reduction products
A B
Facilitates the EC reaction
10
Role of electrode potential E
0
20
40
60
80
100
0 400 800 1200 1600
E (mV)
Sig
nal
(%
)
2000
formation of secondary products
A B C
B C
B: instable intermediate
How to Find Optimum ΔE ?
Traditional Electrochemistry: VoltammogramOn-line EC/ESI-MS: “MS Voltammogram”
180 200 220 240 260 280 300 320 340 360 380 4000
1000
2000
3000
4000
5000
1500
2500
2000
inte
nsity
[-]
m/z
E [mV]
11
oxidative degradation of the substrate
oxidation products
oxidation products
Typical Reactions Catalyzed by Cytochrome P450 Simulated by EC
Allylic and aliphatic hydroxylation
Possible at high potentials
(only with ROXY)
Benzylic hydroxylation
Possible
Desalkylation of amines Possible
Desalkylation of ethers and thioethers
Ethers: Possible
Tioethers: not mimicked
Hydroxylation of aromatics
Possible
Epoxide formation Possible
Oxidation of heteroatoms (N, S)
Possible
Adapted from W. Lohmann et al. LC/GC Jan. 2010
R-CH2-CH3 R-CH-CH3
OH
RR R
OH
R
OH
N-CH2-R NH + R-CHO
R-O-CH2-R R-OH + RCHO
RRR
OH
R
OH
O
C=CR
C CR
C CR
HO OH
R C NH R R C+ N RO-
RR
H
Proteomics
Electrochemical cleavage (oxidation) of proteins/peptides
‘enzymatic digestion’ by electro-chemical cell
no enzymes, no non-specific cleavage, no auto-digestion, etc.
13
Electrochemistry in Proteomics
14
Electrochemistry in Proteomics
15
Electrochemistry in Proteomics
16
Conclusion EC/MS
Many application areasTime and cost savings...Fast and clean
17
Conclusion EC/MS
Mimics Natures Redox Reactions
Drug developmentImmediate results, minutes vs weeks
No by products, no cleanupNo biohazardNo rodents
ProteomicsNo enzymes, clean without by products
18
Thank you!
www.myAntec.com