Neopinone isomerase and methods of using

1. A method of making a second morphinan compound having a saturated carbon bond at position C8-C14 and a mono-unsaturated carbon bond at position C7-C8, the method comprising:

providing a host cell transformed with an expression construct comprising a nucleic acid sequence encoding neopinone isomerase and expressing the neopinone isomerase with a first morphinan compound having a mono-unsaturated carbon bond at position C8-C14 and a saturated carbon bond at position C7-C8

under reaction conditions permitting the conversion of the first morphinan compound into the second morphinan compound;

wherein the neopinone isomerase is a polypeptide encoded by:

(i) a nucleic acid molecule comprising a nucleic acid sequence of each of SEQ ID NO: 14, SEQ ID NO: 15, SEQ ID NO: 16, and SEQ ID NO: 17;

(ii) a nucleic acid molecule comprising a nucleic acid sequence having at least 90% identity to each of SEQ ID NO: 14, SEQ ID NO: 15, SEQ ID NO: 16 and SEQ ID NO: 17; or

(iii) a nucleic acid molecule comprising within the nucleic acid molecule a nucleic acid sequence having at least 90% identity to each of SEQ ID NO: 14, SEQ ID NO: 15, SEQ ID NO: 16 and SEQ ID NO: 17 but for the degeneration of the genetic code or

wherein the neopinone isomerase is:

(iv) a polypeptide comprising each of the amino acid sequences SEQ ID NO: 18, SEQ ID NO: 19, SEQ ID NO: 20, and SEQ ID NO: 21; or

(v) a polypeptide comprising within the polypeptide an amino acid sequence having at least 90% identity to each of the amino acid sequences SEQ ID NO: 18, SEQ ID NO: 19, SEQ ID NO: 20, and SEQ ID NO: 21.

2. The method according to claim 1 , wherein the method further comprises isolating the second morphinan compound.

3. The method according to claim 1 , wherein the first and second morphinan compounds possess a bridging oxygen atom between carbon atoms C4 and C5, forming a tetrahydrofuranyl ring within the morphinan chemical structure.

4. The method according to claim 1 , wherein the first morphinan compound is a chemical compound having the chemical structure (I):

the second morphinan compound is a chemical compound having the chemical structure (II):

wherein R 1 is either a hydroxyl group or a methoxy group.

5. The method according to claim 4 , the method further comprising transforming the host cell with an expression construct comprising a nucleic acid sequence encoding codeinone reductase and expressing the codeinone reductase,

wherein the R 1 of the second morphinan compound is a methoxy group, and

wherein reaction conditions permitting the conversion of the second morphinan compound into a third morphinan compound having the chemical structure (III):

6. The method according to claim 5 , wherein the method further comprises isolating the third morphinan compound having chemical structure (Ill).

7. The method according to claim 5 , wherein additionally a fourth morphinan having the chemical structure (IV):

is formed, and

wherein the quantity of compound (IV) upon completion of the reaction does constitute no more than 20% (w/w) of all morphinan compounds.

8. The method according to claim 7 , wherein, compound (IV) upon completion of the reaction constitutes no more than 15%, 14%, 13%, 12%, 11%, 10%, 9%, 8%, 7%, 6%, 5%, 4%, 3%, 2% of 1% (w/w) of all morphinan compounds.

9. The method according claim 5 , the method further comprising transforming the host cell with an expression construct comprising a nucleic acid sequence encoding codeinone-O-demethylase and expressing the codeinone-O-demethylase,

wherein reaction conditions permitting the conversion of the third morphinan compound into a fourth morphinan compound having the chemical structure (V):

10. The method according to claim 9 , wherein the method further comprises isolating the fourth morphinan compound having chemical structure (V).