Jun.28,2007  27  US 2007/0148124 Al  TABLE I-continued  TABLE I-continued  *R - the moiety, that when covalently attached to the polymer, copolymer,  or oligomer backbone, results in a molecule that is able to remain molecu› larly dispersed, and mostly dissociated, in solution over a wide range of  pH. Ras defined, refers to any one of R 1 ,  R 2 ,  R 3 ,  R 4 ,  or R 5 ,  as defined  herein.  **pKa values given at room temperature and taken from a variety of  sources including (Hall, H.K., J. Am Chem. Soc. 79:5439-5441, 1957;  Handbook of Chemistry and Physics (Hodgman, C.D., editor on Chief,  Chemical Rubber Publishing Company, Cleveland, OH p. 1636-1637,  1951).  [0266]  In the examples of Table  1,  except for maleic and  succinic acid, the linkage to the oxygen atom by R1, R 2 , R 3 ,  R 4  and Rs is via an ester through an acyl group of the  carboxylic acid or anhydride. However, with respect to the  acrylic polymers, the linkage of the maleic acid and succinic  acid by Rs is obtained by replacing a hydrogen atom of the  CH$_{2 }$ in succinic acid or a hydrogen atom of CH=CH in  maleic acid with a bond to the oxygen atom in the polymer.  However, the linkage of the maleic and succinic acid of R  1 ,  R 2 , R 3  and R 4  in the cellulose based polymer to the oxygen  atom is through the acyl group.  [0267]  It is understood to one skilled in synthetic organic  chemistry that Table  1  represents only a partial list of  suitable substituents, and that many more examples are  possible provided that no other reactive functionalities are  present which would compete with the primary desired  reaction of forming substituted cellulose- or acrylic-based  polymers or oligomers. One skilled in the art can prepare  one or more active compounds in this class by performing  the above synthesis or similar methods using combinatorial  synthesis or equivalent schemes by altering the monocar› boxylic acid moiety, or the di- or tri-carboxylic acid moiety,  or a mixed moiety containing both carboxylic acid groups  and sulfate or sulfonate groups, or a moiety containing a  sulfate or sulfonate group. Furthermore, additional hydro› phobicity can be added using techniques known in the art on  those resulting molecules. This can be accomplished in a  number of ways including the addition of a naphthalene  group such as those shown in Table  1  (naphthalene tetra› carboxylic dianhydride or naphthalimide) to the cellulose  backbone.  [0268]  Other substituents for R1, R 2 , R 3 , R 4  of Formula I  or Rs of Formula II are obtained by using a mixture of the  moieties identified or suggested herein or in Table  1.  Hydroxypropyl methylcellulose acetate maleate (HPMC› AM) is just such a compound in which a mixture of acetic  and maleic anhydride is used to derivatize the hydroxypro› pyl methyl cellulose backbone, and is illustrative of the  compounds of the present invention.  Substitutions for cellulose or acrylic based oligomers, copolymers, or  ol mers.  *R  1,8-Naphthalic anhydride  0  0  1,4,5 ,8-Naphthalene  tetracarboxylic acid  dianhydride  2-sulfobanzoic acid  cyclic anhydride  o=s=o  I  OK  1,8-Naphthalic anhydride  COOR  ~OH  ~OH  COOR  Tartaric Acid  (+)-2.99,  4.4  (-)-3.03,  4.4  Meso- 3.22, 4.85  **pKa  Values  Substitutions for cellulose or acrylic based oligomers, copolymers, or  ol mers.  *R  /"--yCOOH  HOOC  I  OH  D or L Mallie Acid  Vinyl acetic acid  **pKa  Values  3.4, 5.2  4.42 