Synthesis of the organoarsenical antibiotic arsinothricin and derivatives thereof
The subject invention provides methods and procedures for synthesis and/or semi-synthesis of the novel antibiotic arsinothricin (AST) and derivatives. Arsinothricin (AST), a new broad-spectrum organoarsenical antibiotic, is a non-proteinogenic analog of glutamate that effectively inhibits glutamine synthetase. The subject invention provides chemical synthesis of an intermediate in the pathway of AST synthesis, hydroxyarsinothricin (AST-OH), which can be converted to AST by enzymatic methylation catalyzed by the ArsM As(III) S-adenosylmethionine methyltransferase. The methods provide a source of the novel antibiotic that will be required for future clinical trials. The subject invention also provides AST derivatives as a new class of antibiotics.
1. A method for synthesizing hydroxyarsinothricin (AST-OH) comprising
mixing halogen or OH-substituted alkane with an arsenous acid or a salt of an arsenous acid in the presence of a base to form a pentavalent arsenic acid;
optionally, adding a reducing agent, a catalytic agent and an acid to form a trivalent arsine;
optionally, adding an oxidizer to increase the oxidation state of As to form a second pentavalent arsenic acid;
adding a malonate compound and a base to form an aminated and carboxylated arsenic acid; and
adding a second acid.
2. A method for synthesizing arsinothricin (AST) comprising steps for synthesizing AST-OH according to claim 1 , and converting AST-OH to AST comprising:
mixing AST-OH with a second reducing agent to reduce the oxidation state of As from V to III;
mixing the mixture with a base for neutralization; and
incubating the mixture with an arsenite methyltransferase.
3. The method according to claim 1 , the halogen or OH-substituted alkane being 2-chloroethanol or 1,2-dichloroethane.
4. The method according to claim 1 , the salt of arsenous acid being As(ONa) 3 .
5. The method according to claim 1 , the reducing agent being SO 2 .
6. The method according to claim 1 , the catalytic agent being KI.
7. The method according to claim 1 , the first and second acid being HCl.
8. The method according to claim 1 , the oxidizer being H 2 O 2 .
9. The method according to claim 1 , the malonate compound being diethyl acetamidomalonate.
10. The method according to claim 1 , the base being a mixture of Na and EtOH.
11. The method according to claim 1 , which consists of:
mixing 2-chloroethanol with an arsenous acid or a salt of an arsenous acid in the presence of a base to form a pentavalent arsenic acid;
adding a reducing agent, a catalytic agent and an acid to form a trivalent arsine, and subsequently, mixing with a halogen donor;
adding an oxidizer to form (2-chloroethyl)arsonic acid;
adding diethyl acetamidomalonate and sodium ethoxide; and
adding second acid.
12. The method according to claim 1 , which comprises:
mixing 1,2-dichloroethane with an arsenous acid or a salt of arsenous acid in the presence of a base to form (2-chloroethyl)arsonic acid;
adding diethyl acetamidomalonate and sodium ethoxide; and
adding an acid.
13. The method according to claim 2 , the second reducing agent being an acidic mixture of Na 2 S 2 O 3 , Na 2 S 2 O 5 and H 2 SO 4 .
14. A derivative of AST having a general structure of formula
wherein X is O or S;
Z is OR 7 or NHCHR 10 R 11 ;
R 1 and R 2 are independently selected from hydrogen, alkyl, substituted alkyl, aryl, substituted aryl, acetyl, benzyl, and benzoyl;
R 3 is hydrogen or alkyl;
R 4 is OH, alkyl, substituted alkyl, aryl, substituted aryl, heteroalkyl, substituted heteroalkyl, acetyl, benzyl, benzoyl or sulfhydryl;
R 5 is alkyl, substituted alkyl, aryl, substituted aryl, heteroalkyl, substituted heteroalkyl, acetyl, benzyl, benzoyl or sulfhydryl;
R 6 is hydrogen, or hydroxyl;
R 7 is hydrogen, alkyl, substituted alkyl, aryl, substituted aryl, benzyl, benzoyl, heteroalkyl, or substituted heteroalkyl;
R 10 is hydrogen, alkyl, or substituted alkyl; and
R 11 is hydrogen, alkyl, substituted alkyl, aryl, substituted aryl, heteroalkyl, substituted heteroalkyl, acyl, alkoxy, amino, or substituted amino.
15. The derivative of AST according to claim 14 , the derivative having a structure of
wherein R 1 and R 2 are independently selected from hydrogen, alkyl, substituted alkyl, benzoyl or benzyl, aryl, and substituted aryl;
R 4 is alkyl, substituted alkyl, aryl, substituted aryl, or sulfhydryl; and
R 7 is hydrogen, alkyl, substituted alkyl, aryl, or substituted aryl.
16. The derivative of AST according to claim 15 , wherein R 1 and R 2 are independently selected from methyl, acetyl, CF 3 CO, benzoyl and benzyl; R 4 is methyl, phenyl, sulfhydryl or thiomethyl; and R 7 is H, methyl, ethyl, propyl, isopropyl, phenyl, or acetoxymethyl.
17. The derivative of AST according to claim 14 , the derivative having a structure of
or
wherein R 1 and R 2 are independently selected from hydrogen, alkyl, substituted alkyl, aryl, and substituted aryl;
R 7 is hydrogen, alkyl, substituted alkyl, aryl, or substituted aryl; and
R 14 is alkyl, substituted alkyl, aryl, or substituted aryl.
18. The derivative of AST according to claim 17 , wherein R 1 and R 2 are independently selected from methyl, acetyl, CF 3 CO, benzoyl and benzyl; R 7 is H, methyl, ethyl, propyl, isopropyl, phenyl, or acetoxymethyl; and R 14 is H, methyl, ethyl, propyl, phenyl, or acetoxymethyl.
19. The derivative of AST according to claim 14 , the derivative having a structure of
wherein R 5 is unsubstituted or substituted C2-C10 alkyl.
20. The derivative of AST according to claim 14 , the derivative having a structure of
wherein X is O or S; Y is N or O; R 10 is alkyl, substituted alkyl, aryl, or substituted aryl; and R 15 is alkyl, substituted alkyl, aryl, substituted aryl, or benzyl.
21. The derivative of AST according to claim 20 , wherein Y is O; and R 15 is methyl, ethyl, propyl, isopropyl, acetoxymethyl, phenyl, CH 2 Ph or benzyl; or
wherein Y is N; and R 15 Y is an amino acid or a peptide comprising two, three, four, or five amino acids.
22. The derivative of AST according to claim 14 , the derivative having a structure of
23. A pharmaceutical composition comprising an AST derivative according to claim 14 , or a salt thereof, and a pharmaceutically acceptable carrier.