Quinone based nitric oxide donating compounds

1. A method of treating Sickle cell disease comprising administering a compound of formula (I) to a patient in need thereof:

or steroisomers thereof, wherein

R 1 is selected from H, methyl, methoxy;

R 3 is selected from H, methyl, methoxy;

or R 1 and R 3 together form —CH═CH—CH═CH—;

R 2 is H, methyl;

n is an integer from 0 to 10;

Q is selected from the group consisting of:

wherein

m is an integer from 0 to 6;

p is an integer from 0 to 1;

X is O, S or is —CHONO 2 , with the proviso that when X is —CHONO 2 then m is 0.