Nitric oxide donating derivatives of fluprostenol

A compound of formula (I) or a salt thereof

• wherein
• R is —CH(CH3)2 or H;
• Ra is selected from
• A1):
• —(CHR1)—NH—(C═O)—(CH2)m—[O—(CH2)n]p—(CH—ONO2)q—CH2—ONO2
• A2):
• —(CH2)2—NH—(C═O)—(CH2)m—[O—(CH2)n]p—(CH—ONO2)q—CH2—ONO2
• A3):
• —(CH2)m—[O—(CH2)n]p—(CH—ONO2)q—CH2—ONO2
• wherein
• R1 is —H or —CH3,
• p is 1 or 0,
• q is 1 or 0,
• m is an integer ranging from 1 to 10;
• n is an integer ranging from 1 to 6.