Patent ID: 7056898

Claim:
A compound of Structure I, comprising: wherein R 1 , R 2 , R 3 , R 4 , R 5 , and R 6 are either SO 3 − , PO 3 − or H; and (a) wherein R 1 , R 2 , R 3 , R 4 , R 5 , and R 6 are each independently either SO 3 − , PO 3 − or —H; and (b) wherein at least five of the group consisting of R 1 , R 2 , R 3 , R 4 , R 5 , and R 6 are each independently either SO 3 − or PO 3 − ; or (c) wherein at least four of the group consisting of R 1 , R 2 , R 3 , R 4 , R 5 , and R 6 are each independently either SO 3 − or PO 3 − ; or (d) wherein at least three of the group consisting of R 1 , R 2 , R 3 , R 4 , R 5 , and R 6 are each independently either SO 3 − or PO 3 − ; and provided that, if (i) R 3 arid R 4 are both SO 3 − then at least one of the group consistig of R 1 , R 2 , R 5 , and R 6 are either SO 3 − or PO 3 − ; or (ii) R 3 , R 4 , R 5 are SO 3 − then at least one of the group consisting of R 1 , R 2 , R 6 are either SO 3 − , or PO 3 − , or (iii) R 1 and R 4 are both SO 3 − and R 3 is not SO 3 − , then at least one of the group consisting or R 2 ,R 5 , and R 6 are either SO 3 − , or PO 3 − .