Drug Metabolism in Drug Design and Development Basic Concepts and Practice

TABLE 12.6 Common 1D NMR experiments and their characteristics.1D NMR experiment

Application

Advantages

Limitations

Comments

1D

1 H

Verify or eliminate

proposed structures bycomparing the changesin chemical shifts,coupling constants,and integrations withthat of the parentmolecule.

Simple, fast, and highly

sensitive. It can beobserved on a sampleas little as 0.5

m

g.

Signal overlaps cannot

be resolved.

Should be used as the

first experiment forany meta bolite IDwork when comparedto its parent molecule

Can not differentiate

HC



O from HC



Nor

HC



O from CH

¼

CR

1D

1 H

with solvent

suppression

Same as above.

Improve the sensitivity

of the proton spectrumfor which the solventsignals is extremelystrong

In addition to the above

some resonances maynot be observed due tooverlap with solventresonances

Should be used when

the solvent signal isstrong and when thesample concentrationis very low

1D NOE

It provides stereochemistry

information Some times,it is used to verifyconnectivity of themolecule.

Extremely powerful for

stereochemistrydetermination andconnectivity verification

Low sensitivity, stable

spectrometer requiredfor long data collection,>

20

m

g of compound

required

Use only where required

or appropriate

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