Biflavanoids and derivatives thereof as antiviral agents

Abstract

Substantially purified antiviral biflavanoids robustaflavone, hinokiflavone, amentoflavone, agathisflavone, volkensiflavone, morelloflavone, rhusflavanone, succedaneaflavanone, GB-1a, and GB-2a are provided. Antiviral biflavanoid derivatives and salt forms thereof, e.g., robustaflavone tetrasulfate potassium salt, and methods for preparing the same are also disclosed. Pharmaceutical compositions which include the antiviral biflavanoids, derivatives or salts thereof are also provided alone or in combination with at least one antiviral agent such as 3TC. Also disclosed is an improved method for obtaining substantially pure robustaflavone from plant material. The biflavanoid compounds, derivatives or salts thereof of the invention may be used in a method for treating and/or preventing viral infections caused by viral agents such as influenza, e.g., influenza A and B; hepatitis, e.g., hepatitis B; human immunodeficiency virus, e.g., HIV-1; Herpes viruses (HSV-1 and HSV-2); Varicella Zoster virus (VZV); and measles. For instance, semi-synthetic hexa-O-acetate and hexa-O-methyl ether derivatives of robustaflavone have been found to be effective in a method for treating or preventing hepatitis B viral infections. Compositions which include these robustaflavone derivatives along with methods for preparing and using the same are also provided. These compositions may be used alone or in combination with at least one antiviral agent such as 3TC.

1 . A method for treating or preventing a viral infection which comprises administering a composition comprising an antivirally effective amount of at least one biflavanoid and at least one antiviral agent.  
     
     
         2 . The method according to  claim 1 , wherein said biflavanoid is selected from the group consisting of robustaflavone, hinokiflavone, amentoflavone, agathisflavone, volkensiflavone, rhusflavanone, succedaneaflavanone, morelloflavone, GB-1a, GB-2a, derivatives or salts thereof.  
     
     
         3 . The method according to  claim 2 , wherein said biflavanoid is robustaflavone.  
     
     
         4 . The method according to  claim 2 , wherein said derivatives or salts thereof comprise alkyl ethers, esters, acid adducts, amines and sulfates.  
     
     
         5 . The method according to  claim 4 , wherein said robustaflavone salt is robustaflavone tetrasulfate potassium salt.  
     
     
         6 . The method according to  claim 4 , wherein said robustaflavone salt is robustaflavone hexa-O-methyl ether.  
     
     
         7 . The method according to  claim 4 , wherein said robustaflavone salt is robustaflavone hexa-O-acetate.  
     
     
         8 . The method according to  claim 4 , wherein said robustaflavone salt is robustaflavone tetrasodium salt.  
     
     
         9 . The method according to  claim 1 , wherein said antiviral agent comprises AZT, ddC, ddI, D4T, lamivudine (3TC), alyclovir, gancyclovir, fluorinated nucleosides, TIBO derivatives, nevirapine, saquinavir, α-interferon and recombinant CD4), imnmunostimulants (e.g., various interleukins and cytokines), immunomodulators and antibiotics (e.g., antibacterial, antifungal, anti-pneumocysitis agents).  
     
     
         10 . The method according to  claim 4 , wherein said antiviral agent is 3TC.  
     
     
         11 . The method according to  claim 1 , wherein said biflavanoid is robustaflavone and said antiviral agent is 3TC.  
     
     
         12 . The method according to  claim 1 , wherein said viral infection is by an influenza virus.  
     
     
         13 . The method according to  claim 12 , wherein said influenza virus is influenza A or influenza B virus.  
     
     
         14 . The method according to  claim 1 , wherein said viral infection is by a hepatitis virus.  
     
     
         15 . The method according to  claim 14 , wherein said hepatitis virus is hepatitis B virus.  
     
     
         16 . The method according to  claim 1 , wherein said viral infection is by a Herpes virus.  
     
     
         17 . The method according to  claim 16 , wherein said Herpes virus is HSV-1 or HSV-2 virus.  
     
     
         18 . The method according to  claim 1 , wherein said viral infection is by a Varicella Zoster Virus (VZV).  
     
     
         19 . The method according to  claim 18 , wherein said viral infection is by a respiratory virus.  
     
     
         20 . The method according to  claim 19 , wherein said respiratory virus is a measles virus.  
     
     
         21 . The method according to  claim 1 , wherein the viral infection is by a retrovirus.  
     
     
         22 . The method according to  claim 21 , wherein the retrovirus is a human immunodeficiency virus (HIV).  
     
     
         23 . The method according to  claim 22 , wherein human immunodeficiency virus (HIV) is HIV- 1.  
     
     
         24 . A pharmaceutical composition for treating and/or preventing viral infections which comprises an antivirally effective amount of at least one substantially purified biflavanoid, at least one antiviral agent and a pharmaceutically acceptable carrier.  
     
     
         25 . The composition according to  claim 24  wherein said biflavanoid comprises robustaflavone, hinokiflavone, amentoflavone, agathisflavone, volkensiflavone, rhusflavanone, succedaneaflavanone, morelloflavone, GB-1a, GB-2a, derivatives or salts thereof.  
     
     
         26 . The composition according to  claim 25 , wherein said biflavanoid is robustaflavone.  
     
     
         27 . The composition according to  claim 25 , wherein said derivatives or salts thereof comprise alkyl ethers, esters, acid adducts, amines and sulfates.  
     
     
         28 . The composition according to  claim 27 , wherein said derivatives or salts thereof is a robustaflavone salt.  
     
     
         29 . The composition according to  claim 25 , wherein said robustaflavone salt is robustaflavone tetrasulfate potassium salt.  
     
     
         30 . The composition according to  claim 25 , wherein said robustaflavone salt is robustaflavone hexa-O-methyl ether.  
     
     
         31 . The composition according to  claim 25 , wherein said robustaflavone is robustaflavone hexa-O-acetate.  
     
     
         32 . The composition according to  claim 25 , wherein said robustaflavone is robustaflavone tetrasodium salt.  
     
     
         33 . The composition according to  claim 24 , wherein said antiviral agent comprises AZT, ddC, ddI, D4T, lamivudine (3TC), alyclovir, gancyclovir, fluorinated nucleosides, TIBO derivatives, nevirapine, saquinavir, α-interferon and recombinant CD4), immunostimulants (e.g., various interleukins and cytokines), immunomodulators and antibiotics (e.g., antibacterial, antifungal, anti-pneumocysitis agents).  
     
     
         34 . The composition according to  claim 33 , wherein said antiviral agent is 3TC.  
     
     
         35 . The composition according to  claim 24 , wherein said biflavanoid is robustaflavone and said antiviral agent is 3TC.  
     
     
         36 . A pharmaceutical composition for treating and/or preventing viral infections which comprises an antivirally effective amount of a biflavanoid derivative.  
     
     
         37 . The composition of  claim 36  wherein said biflavanoid derivative comprises robustaflavone hexa-O-methyl ether, robustaflavone hexa-O-acetate, and robustaflavone tetrasodium salt and a pharmaceutically acceptable carrier.  
     
     
         38 . A method for treating or preventing a viral infection which comprises administering an antiviral effective amount of a biflavanoid derivative.  
     
     
         39 . The method according to  claim 38  wherein said biflavonoid derivative comprises robustaflavone hexa-O-methyl ether.  
     
     
         40 . The method according to  claim 38  wherein said biflavonoid derivative comprises robustaflavone hexa-O-acetate.  
     
     
         41 . The method according to  claim 38  wherein said biflavonoid derivative comprises robustaflavone tetrasodium salt.  
     
     
         42 . A method for treating or preventing a hepatitis B viral infection which comprises administering a composition comprising an antivirally effective amount of robustaflavone hexa-O-acetate.  
     
     
         43 . A method for treating or preventing a hepatitis B viral infection which comprises administering a composition comprising an antivirally effective amount of robustaflavone hexa-O-methyl ether.  
     
     
         44 . A method for treating or preventing a hepatitis B viral infection which comprises administering a composition comprising an antivirally effective amount of robustaflavone tetrasodium salt.  
     
     
         45 . The method according to claims  42 ,  43 , or  44 , further comprising administering at least one other antiviral agent.  
     
     
         46 . The method according to  claim 45 , wherein said antiviral agent comprises AZT, ddC, ddI, D4T, lamivudine (3TC), alyclovir, gancyclovir, fluorinated nucleosides, TIBO derivatives, nevirapine, saquinavir, α-interferon and recombinant CD4), immunostimulants (e.g., various interleukins and cytokines), immunomodulators and antibiotics (e.g., antibacterial, antifungal, anti-pneumocysitis agent).  
     
     
         47 . The method according to  claim 45 , wherein said antiviral agent comprises AZT, ddC, ddI, D4T, lamivudine (3TC), alyclovir, gancyclovir, fluorinated nucleosides, TIBO derivatives, nevirapine, saquinavir, α-interferon and recombinant CD4), immunostimulants (e.g., various interleukins and cytokines), immunomodulators and antibiotics (e.g., antibacterial, antifungal, anti-pneumocysitis agents).  
     
     
         48 . The method according to claims  45 , wherein said antiviral agent is 3TC.  
     
     
         49 . A pharmaceutical composition for treating and/or preventing a hepatitis B viral infection which comprises an antivirally effective amount of robustaflavone hexa-O-acetate and a pharmaceutically acceptable carrier.  
     
     
         50 . A pharmaceutical composition for treating and/or preventing a hepatitis B viral infection which comprises an antivirallv effective amount of robustaflavone hexa-O-methyl ether and a pharmaceutically acceptable carrier.  
     
     
         51 . A pharmaceutical composition for treating and/or preventing a hepatitis B viral infection which comprises an antivirally effective amount of robustaflavone tetradsodium salt and a pharmaceutically acceptable carrier.  
     
     
         52 . The pharmaceutical composition according to claims  49 - 51  further comprising at least one other anti-viral agent comprising AZT, ddC, ddI, D4T, lamivudine (3TC), alyclovir, gancyclovir, fluorinated nucleosides, TIBO derivatives, nevirapine, saquinavir, α-interferon and recombinant CD4), immunostimulants (e.g., various interleukins and cytokines), immunomodulators and antibiotics (e.g., antibacterial, antifungal, anti-pneumocysitis agents).