Compositions and methods for treating microbial infections

Abstract

Embodiments of the presently-disclosed subject matter include activators of HssRS that induce endogenous heme biosynthesis by perturbing central metabolism. These molecules are toxic to fermenting S. aureus , including clinically relevant small colony variants (SCVs). The utility of targeting fermenting bacteria is exemplified by the fact that this compound prevents the emergence of antibiotic resistance, enhances phagocyte killing, and reduces S. aureus pathogenesis. This small molecule is a powerful tool not only for studying bacterial heme biosynthesis and central metabolism, but also establishes targeting of fermentation as a viable antibacterial strategy.

1 . A method for treating a microbial infection, comprising: administering an effective amount of a fermentation inhibitor, comprising a compound of the formula: 
       
         
           
           
               
               
           
         
         wherein, 
         R 1  is H, alkyl, aryl, heteroaryl; 
         R 2  is H, halogen, alkyl, aryl, heteroaryl; 
         R 3  is H, hydroxyl, alkoxy, alkyl, aryl, heteroaryl, amino, amino sulfonyl, acetamide; 
         R 4  is H, hydroxyl, alkoxy, alkyl, aryl, heteroaryl, amino, amino sulfonyl, acetamide; 
         R 5  is H, hydroxyl, alkoxy, alkyl, aryl, heteroaryl, amino, amino sulfonyl, acetamide; 
         R 6  is H, hydroxyl, alkoxy, alkyl, aryl, heteroaryl, amino, amino sulfonyl, acetamide; 
         R 7  is H, hydroxyl, alkoxy, alkyl, aryl, heteroaryl, amino, amino sulfonyl, acetamide; 
         R 8  is —CR 3 , O, S; 
         wherein R 5  and R 6 , R 7  and R 6 , R 5  and R 4 , R 4  and R 3  can cyclize forming a 3-10 member ring comprising C, O, S, and/or N optionally substituted with one or more R 3 . 
       
     
     
         2 . The method of  claim 1 , wherein:
 R 1  is H, alkyl, aryl;   R 2  is H, halogen, alkyl, aryl, heteroaryl;   R 3  is H, alkyl, hydroxyl, alkoxy, amino, amino sulfonyl, acetamide, aryl, heteroaryl;   R 4  is H, alkyl, hydroxyl, alkoxy, amino, amino sulfonyl, acetamide;   R 5  is H, alkyl, hydroxyl, alkoxy, amino, amino sulfonyl, acetamide;   R 6  is H, alkyl, aryl.   
     
     
         3 . The method of  claim 1 , wherein
 R 1  is H or   
       
         
           
           
               
               
           
         
         R 2  is 
       
       
         
           
           
               
               
           
         
         R 3  is H, OH, 
       
       
         
           
           
               
               
           
         
         R 4  is H, OH, 
       
       
         
           
           
               
               
           
         
         or R 4  and R 5 , taken together with the carbon atoms to which they are bonded, can form an aromatic ring containing 6 carbon atoms; 
         R 5  is H, OH, 
       
       
         
           
           
               
               
           
         
         or R 4  and R 5 , taken together with the carbon atoms to which they are bonded, can form an aromatic ring containing 6 carbon atoms, or R 5  and R 6 , taken together with the carbon atoms to which they are bonded, can form an aromatic ring containing 6 carbon atoms; 
         R 6  is H, or R 5  and R 6 , taken together with the carbon atoms to which they are bonded, can form an aromatic ring containing 6 carbon atoms; 
         R 7  is H or OH; and 
         R 8  is O or S. 
       
     
     
         4 . The method of  claim 1 , wherein the fermentation inhibitor is selected from the compounds set forth in Table 1. 
     
     
         5 . (canceled) 
     
     
         6 . The method of  claim 1 , and further comprising administering an antimicrobial. 
     
     
         7 . The method of  claim 6 , wherein the antimicrobial in an antibiotic. 
     
     
         8 - 20 . (canceled) 
     
     
         21 . A composition, comprising:
 a fermentation inhibitor comprising a compound of the formula   
       
         
           
           
               
               
           
         
         wherein, 
         R 1  is H, alkyl, aryl, heteroaryl; 
         R 2  is H, halogen, alkyl, aryl, heteroaryl; 
         R 3  is H, hydroxyl, alkoxy, alkyl, aryl, heteroaryl, amino, amino sulfonyl, acetamide; 
         R 4  is H, hydroxyl, alkoxy, alkyl, aryl, heteroaryl, amino, amino sulfonyl, acetamide; 
         R 5  is H, hydroxyl, alkoxy, alkyl, aryl, heteroaryl, amino, amino sulfonyl, acetamide; 
         R 6  is H, hydroxyl, alkoxy, alkyl, aryl, heteroaryl, amino, amino sulfonyl, acetamide; 
         R 7  is H, hydroxyl, alkoxy, alkyl, aryl, heteroaryl, amino, amino sulfonyl, acetamide; 
         R 8  is —CR 3 , O, S; 
         wherein R 5  and R 6 , R 7  and R 6 , R 5  and R 4 , R 4  and R 3  can cyclize forming a 3-10 member ring comprising C, O, S, and/or N optionally substituted with one or more R 3 . 
       
     
     
         22 . The composition of  claim 21 , wherein:
 R 1  is H, alkyl, aryl;   R 2  is H, halogen, alkyl, aryl, heteroaryl;   R 3  is H, alkyl, hydroxyl, alkoxy, amino, amino sulfonyl, acetamide, aryl, heteroaryl;   R 4  is H, alkyl, hydroxyl, alkoxy, amino, amino sulfonyl, acetamide;   R 5  is H, alkyl, hydroxyl, alkoxy, amino, amino sulfonyl, acetamide;   R 6  is H, alkyl, aryl.   
     
     
         23 . The composition of  claim 22 , wherein
 R 1  is H or   
       
         
           
           
               
               
           
         
         R 2  is 
       
       
         
           
           
               
               
           
         
         R 3  is H, OH, 
       
       
         
           
           
               
               
           
         
         R 4  is H, OH, 
       
       
         
           
           
               
               
           
         
         or R 4  and R 5 , taken together with the carbon atoms to which they are bonded, can form an aromatic ring containing 6 carbon atoms; 
         R 5  is H, OH, 
       
       
         
           
           
               
               
           
         
         or R 4  and R 5 , taken together with the carbon atoms to which they are bonded, can form an aromatic ring containing 6 carbon atoms, or R 5  and R 6 , taken together with the carbon atoms to which they are bonded, can form an aromatic ring containing 6 carbon atoms; 
         R 6  is H, or R 5  and R 6 , taken together with the carbon atoms to which they are bonded, can form an aromatic ring containing 6 carbon atoms; 
         R 7  is H or OH. 
       
     
     
         24 . The composition of  claim 21 , wherein the fermentation inhibitor is selected from the compounds set forth in Table 1. 
     
     
         25 . (canceled) 
     
     
         26 . The composition of  claim 21 , and further comprising administering an antimicrobial. 
     
     
         27 - 42 . (canceled) 
     
     
         43 . A compound have the structure 
       
         
           
           
               
               
           
         
         wherein, 
         R 1  is H, alkyl, aryl, heteroaryl; 
         R 2  is H, halogen, alkyl, aryl, heteroaryl; 
         R 3  is H, hydroxyl, alkoxy, alkyl, aryl, heteroaryl, amino, amino sulfonyl, acetamide; 
         R 4  is H, hydroxyl, alkoxy, alkyl, aryl, heteroaryl, amino, amino sulfonyl, acetamide; 
         R 5  is H, hydroxyl, alkoxy, alkyl, aryl, heteroaryl, amino, amino sulfonyl, acetamide; 
         R 6  is H, hydroxyl, alkoxy, alkyl, aryl, heteroaryl, amino, amino sulfonyl, acetamide; 
         R 7  is H, hydroxyl, alkoxy, alkyl, aryl, heteroaryl, amino, amino sulfonyl, acetamide; 
         R 8  is —CR 3 , O, S; 
         wherein R 5  and R 6 , R 7  and R 6 , R 5  and R 4 , R 4  and R 3  can cyclize forming a 3-10 member ring comprising C, O, S, and/or N optionally substituted with one or more R 3 . 
       
     
     
         44 . The compound of  claim 43 , wherein:
 R 1  is H, alkyl, aryl;   R 2  is H, halogen, alkyl, aryl, heteroaryl;   R 3  is H, alkyl, hydroxyl, alkoxy, amino, amino sulfonyl, acetamide, aryl, heteroaryl;   R 4  is H, alkyl, hydroxyl, alkoxy, amino, amino sulfonyl, acetamide;   R 5  is H, alkyl, hydroxyl, alkoxy, amino, amino sulfonyl, acetamide;   R 6  is H, alkyl, aryl.   
     
     
         45 . The compound of  claim 44 , wherein:
 R 1  is H or   
       
         
           
           
               
               
           
         
         R 2  is 
       
       
         
           
           
               
               
           
         
         R 3  is H, 
       
       
         
           
           
               
               
           
         
         R 4  is H, OH, 
       
       
         
           
           
               
               
           
         
         or R 4  and R 5 , taken together with the carbon atoms to which they are bonded, can form an aromatic ring containing 6 carbon atoms; 
         R 5  is H, OH, 
       
       
         
           
           
               
               
           
         
         or R 4  and R 5 , taken together with the carbon atoms to which they are bonded, can form an aromatic ring containing 6 carbon atoms, or R 5  and R 6 , taken together with the carbon atoms to which they are bonded, can form an aromatic ring containing 6 carbon atoms; 
         R 6  is H, or R 5  and R 6 , taken together with the carbon atoms to which they are bonded, can form an aromatic ring containing 6 carbon atoms; 
         R 7  is H or OH. 
       
     
     
         46 . The compound of  claim 44 , having a structure as set forth in Table 1. 
     
     
         47 . The compound of  claim 43 , and further comprising a label-modification, wherein the compound is of the formula: 
       
         
           
           
               
               
           
         
         wherein, R 1  is H or 
       
       
         
           
           
               
               
           
         
         R 2  is 
       
       
         
           
           
               
               
           
         
         R 3  is H, OH, 
       
       
         
           
           
               
               
           
         
         R 4  is H, OH, 
       
       
         
           
           
               
               
           
         
         or R 4  and R 5 , taken together with the carbon atoms to which they are bonded, can form an aromatic ring containing 6 carbon atoms; 
         R 5  is H, OH, 
       
       
         
           
           
               
               
           
         
         or R 4  and R 5 , taken together with the carbon atoms to which they are bonded, can form an aromatic ring containing 6 carbon atoms, or R 5  and R 6 , taken together with the carbon atoms to which they are bonded, can form an aromatic ring containing 6 carbon atoms; 
         R 6  is H, or R 5  and R 6 , taken together with the carbon atoms to which they are bonded, can form an aromatic ring containing 6 carbon atoms; 
         R 7  is H or OH. 
       
     
     
         48 . The composition of  claim 21 , and further comprising an antibiotic. 
     
     
         49 . The composition of  claim 21 , and further comprising a pharmaceutically-acceptable carrier. 
     
     
         50 . A system, comprising a device for creating an anaerobic environment adjacent a microbial infection; and a fermentation inhibitor comprising the composition of  claim 21 . 
     
     
         51 . A method for screening for a compound useful for inhibiting fermentation, comprising providing a first culture of bacteria and a second culture of bacteria; depriving said cultures of oxygen; contacting the first culture with a composition of  claim 21 ; contacting the second culture with a test compound; and identifying the test compound as a compound useful for inhibiting fermentation if there is a reduction in colonies in the second culture that is the same or less than a reducing in colonies in the first culture.