Reference no: EM133037847

CHT214 Formative Workshop

Question 1. Answer ALL parts a) - d).

Compound 1 is an anti-arrythmia drug that is obtained as a single enantiomer using the following one-pot, multi-enzyme mixture:

a) Draw structures for compounds A and B.

b) Which compound(s) is (are) consumed in this de-racemisation process?

c) Briefly explain why the enzyme formate dehydrogenase is added to the reaction mixture.

d) Write a curly arrow mechanism for the following reaction in the cascade that clearly shows the role of the co-factor NADH.

Question 2. Answer ALL parts a) - d).

Pictet-Spenglerases have been shown to catalyse reactions similar to the one shown below.

(a) Write a curly-arrow mechanism for this reaction.

(b) A product D (MW = 255; [α]D > 0°) when pyruvate and the hydroxybenzylamine C were incubated with a Pictet-Spenglerase and an (S)-selective transaminase. Propose a structure for D and briefly explain why a large excess of pyruvate was added to the reaction mixture.

(c) The same (S)-transminase was used in the following enzyme cascade:

Draw the structure of the co-factor required by the enzyme acetohydroxyacid synthase and propose a structure for the product E.

(d) Propose a structure for the reagent F and briefly explain why it is added at the same concentration as the starting aldehyde even though the initial concentration of pyruvate is 100x lower.