Sialidase inhibitors and preparation thereof

Patent metadata

Field	Value
Publication number	US-11325936-B2
Application number	US-201816608640-A
Country	US
Kind code	B2
Filing date	Apr 27, 2018
Priority date	Apr 27, 2017
Publication date	May 10, 2022
Grant date	May 10, 2022

Abstract

New 2-deoxy-2,3-dehydro-sialic acids and 2,7-anhydro-sialic acids, which are useful as sialidase inhibitors, and enzymatic methods for preparing them are disclosed. The methods include forming a reaction mixture comprising a glycoside acceptor, a sialic acid donor, and a sialyltransferase; maintaining the reaction mixture under conditions sufficient to form a sialoside; and contacting the sialoside with a Streptococcus pneumoniae sialidase to form the sialic acid product. Methods for the inhibition and sialidases and the treatment of cancer and infectious diseases are also disclosed.

First claim

What is claimed is:

1. A method for preparing a 2-deoxy-2,3-dehydro-sialic acid, the method comprising:
forming a reaction mixture comprising a glycoside acceptor, a sialic acid donor, and a sialyltransferase;
maintaining the reaction mixture under conditions sufficient to form a sialoside; and
contacting the sialoside with a Streptococcus pneumoniae sialidase to form the 2-deoxy-2,3-dehydro-sialic acid.

2. The method of claim 1 , wherein the 2-deoxy-2,3-dehydro-sialic acid is a compound according to Formula I:

or a salt thereof, wherein:
R 1 , R 2 , R 3 , and R 4 are independently selected from the group consisting of —NHC(O)R a , —N 3 , —NH 2 , —NHR a , —OC(O)R a , —OH, and hydrogen;
R 5 is selected from the group consisting of —NHAc, —NHGc, —NHC(O)R a , —N 3 , —NH 2 , —OC(O)R a , —OH, and hydrogen;
Ac is —C(O)CH 3 ;
Gc is —C(O)CH 2 OH); and
each R a is independently selected from the group consisting of C 1-12 alkyl, C 1-12 haloalkyl, C 3-10 cycloalkyl, C 6-10 aryl, and C 7-22 arylalkyl.

3. The method of claim 2 , wherein the Streptococcus pneumoniae sialidase is SpNanC having the amino acid sequence set forth in SEQ ID NO:1 or TIGR4 SpNanC having the amino acid sequence set forth in SEQ ID NO:2.

4. The method of claim 1 , wherein the sialoside is an α2-3-linked sialoside.

5. The method of claim 4 , wherein the α2-3-linked sialoside is selected from the group consisting of Neu5Acα2-3Lac, Neu5Gcα2-3Lac, Neu5TFAα2-3Lac, Neu5Acα2-3LacβProN 3 , Neu5Gcα2-3LacβProN 3 , Neu5TFAα2-3LacβProN 3 , Neu5Acα2-3LacβProNHCbz, Neu5Gcα2-3LacβProNHCbz, Neu5TFAα2-3LacβProNHCbz, Neu5Acα2-3LacβProNHFmoc, Neu5Gcα2-3LacβProNHFmoc, and Neu5TFAα2-3LacβProNHFmoc.

6. The method of claim 1 , wherein the sialyltransferase is PmST1_M144D comprising the amino acid sequence set forth in SEQ ID NO:4.

7. The method of claim 1 , wherein the glycoside acceptor is a lactoside comprising a carboxybenzyl (Cbz)-protected amine or a fluorenylmethyloxycarbonyl (Fmoc)-protected amine.

8. The method of claim 7 , wherein the glycoside acceptor is a lactoside Lacβ-OR, wherein R is Cbz-protected C 1-6 alkyl amine or Fmoc-protected C 1-6 alkyl amine.

9. The method of claim 8 , wherein R is Cbz-protected propyl amine or Fmoc-protected propyl amine.

10. A method for preparing a 2,7-anhydro-sialic acid, the method comprising:
forming a reaction mixture comprising a glycoside acceptor, a sialic acid donor, and a sialyltransferase, wherein the glycoside acceptor is a lactoside comprising a carboxybenzyl (Cbz)-protected amine or a fluorenylmethyloxycarbonyl (Fmoc)-protected amine;
maintaining the reaction mixture under conditions sufficient to form a sialoside; and
contacting the sialoside with a Streptococcus pneumoniae sialidase to form the 2,7-anhydro-sialic acid.

11. The method of claim 10 , wherein the glycoside acceptor is a lactoside Lacβ-OR, wherein R is Cbz-protected C 1-6 alkyl amine or Fmoc-protected C 1-6 alkyl amine.

12. The method of claim 11 , wherein R is Cbz-protected propyl amine or Fmoc-protected propyl amine.

13. The method of claim 10 , wherein the 2,7-anhydro-sialic acid is a compound according to Formula II:

or a salt thereof, wherein:
R 11 , R 12 , and R 14 are independently selected from the group consisting of —NHC(O)R a , —N 3 , —NH 2 , —NHR a , —OC(O)R a , —OH, and hydrogen;
R 15 is selected from the group consisting of —NHAc, —NHGc, —NHC(O)R a , —N 3 , —NH 2 , —OC(O)R a , —OH, and hydrogen;
Ac is —C(O)CH 3 ;
Gc is —C(O)CH 2 OH); and
each R a is independently selected from the group consisting of C 1-12 alkyl, C 1-12 haloalkyl, C 3-10 cycloalkyl, C 6-10 aryl, and C 7-22 arylalkyl.

14. The method of claim 10 , wherein the Streptococcus pneumoniae sialidase is SpNanB having the amino acid sequence set forth in SEQ ID NO:3.

15. The method of claim 10 , wherein the sialoside is an α2-3-linked sialoside.

16. The method of claim 15 , wherein the α2-3-linked sialoside is selected from the group consisting of Neu5Acα2-3LacβProNHCbz, Neu5Gcα2-3LacβProNHCbz, Neu5TFAα2-3LacβProNHCbz, Neu5Acα2-3LacβProNHFmoc, Neu5Gcα2-3-LacβProNHFmoc, and Neu5TFAα2-3LacβProNHFmoc.

17. The method of claim 10 , wherein the sialyltransferase is PmST1_M144D comprising the amino acid sequence set forth in SEQ ID NO:4.

Assignees

• Univ California

Inventors

• Chen Xi
• Xiao An
• Li Wanqing
• Li Xixuan
• Li Yanhong
• Slack Teri

Classifications

• C07D309/30 Primary

  Oxygen atoms, e.g. delta-lactones · CPC title

• C07H13/04

  having the esterifying carboxyl radicals attached to acyclic carbon atoms · CPC title

• A61K31/7012

  Compounds having a free or esterified carboxyl group attached, directly or through a carbon chain, to a carbon atom of the saccharide radical, e.g. glucuronic acid, neuraminic acid (gluconic acid A61K31/191; ascorbic acid A61K31/375) · CPC title

• C07H1/00

  Processes for the preparation of sugar derivatives · CPC title

• C07H15/207

  Cyclohexane rings not substituted by nitrogen atoms, e.g. kasugamycins · CPC title