Novel aminoglycoside antibiotics

Abstract

This invention relates to novel aminoglycoside antibiotics, which have potent antimicrobial activity against bacteria, which induce infectious diseases, particularly MRSA, and has no significant nephrotoxicity, and process for producing them. More particularly, the present invention relates to compounds represented by formula (Ia) or their pharmacologically acceptable salts or solvates, or their diastereomer mixtures, antimicrobial agents comprising them, and a process for producing them.

1 - 36 . (canceled) 
     
     
         37 . A compound represented by formula (Xa): 
       
         
           
           
               
               
           
         
         wherein R 5ax  and R 5eq , which are different from each other, represent a hydrogen atom or hydroxyl. 
       
     
     
         38 . A compound represented by formula (XXV): 
       
         
           
           
               
               
           
         
         wherein
 R 2  and G represent a protective group for hydroxyl, 
 R 3 , R 2′ , R 6′  and E represent a protective group for amino, 
 n is an integer of 1 to 4, and 
 the steric configuration of carbon atom attached with * represents R or S, or its diastereomer mixture with respect to the carbon atom attached with *. 
 
       
     
     
         39 . The compound according to  claim 38  or its diastereomer mixture with respect to the carbon atom attached with *, wherein
 R 2  represents optionally substituted aryl C1-3 alkyl, 
 R 3 , R 2′  and R 6′ , which may be the same or different, represent
 optionally substituted C1-6 alkyl sulfonyl, 
 optionally substituted aryl sulfonyl, or 
 optionally substituted C1-6 alkyloxycarbonyl, 
 
 E represents optionally substituted C1-6 alkyloxycarbonyl, and 
 G represents a hydrogen atom,
 optionally substituted C1-6 alkylcarbonyl, 
 optionally substituted arylcarbonyl, or 
 optionally substituted aryl C1-3 alkyl. 
 
 
     
     
         40 . The compound according to  claim 38  or its diastereomer mixture with respect to the carbon atom attached with *, wherein
 R 2  represents aryl C1-3 alkyl optionally substituted by methoxy or nitro, 
 R 3 , R 2′  and R 6′ , which may be the same or different, represent
 C1-6 alkylsulfonyl optionally substituted by optionally substituted phenyl, arylsulfonyl optionally substituted by methyl, or 
 C1-6 alkyloxycarbonyl optionally substituted by optionally substituted phenyl, 
 
 E represents C1-6 alkyloxycarbonyl optionally substituted by optionally substituted phenyl, and 
 G represents a hydrogen atom,
 C1-6 alkylcarbonyl, 
 arylcarbonyl, or 
 aryl C1-3 alkyl optionally substituted by methoxy. 
 
 
     
     
         41 . The compound according to  claim 38  or its diastereomer mixture with respect to the carbon atom attached with *, wherein
 R 2  represents benzyl, methoxybenzyl or nitrobenzyl, 
 R 3 , R 2′  and R 6′ , which may be the same or different, represent 
 methanesulfonyl, benzyl sulfonyl, 
 p-toluenesulfonyl, 
 benzyloxycarbonyl, tert-butoxycarbonyl, p-methoxybenzyloxycarbonyl, or p-nitrobenzyloxycarbonyl, 
 E represents benzyloxycarbonyl, and 
 G represents a hydrogen atom,
 acetyl, 
 benzoyl, benzyl, p-methoxybenzyl, or triphenylmethyl. 
 
 
     
     
         42 . A compound represented by formula (Xb): 
       
         
           
           
               
               
           
         
         wherein
 R 5ax  and R 5eq , which are different from each other, represent a hydrogen atom or hydroxyl, and 
 R 4″ax  and R 4″eq , which are different from each other, represent a hydrogen atom or hydroxyl. 
 
       
     
     
         43 . A compound represented by formula (XIV):