h3C-S sXHa h3C-S sXHa m/z 159 m/z 173

Q6. The molecule can only be constructed from acetate and propionate by starting on the right-hand side. It contains two acetates and three propionates. Any of a number of ways of labelling could be used. Radio-labelling would be less useful because the molecule would have to be degraded to find where the label was located. CD3 labelling of propionic acid would show up in the mass spectrum, but best would be labelling with 2,3-[13C]propionic acid and the 13C-13C coupling at the places indicated by asterisks should be seen.

Q7. Incorporation is 20.79%. It is much easier to get high incorporations like this when using excised tissues or glands.

Chapter 6

Q1. An oxidase will convert oc-pinene to cw-verbenol.


Q2. Made from a-farnesene. An «-oxidation is required (-CH3 —> -CH2OH —>

CHO) to produce the aldehyde at the 'wrong' end of the chain. Q3. To check, see Figure 6.12, although there can be some mixing of the label in the terminal dimethyl group of geranyl pyrophosphate.

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