Raltitrexed thymidylate synthase inhibitor OH H2N NH Hydroxycarbamide HO Ribonucleotide reductase inhibitor pentostatin Adenosine deaminase inhibitor IV治疗毛细胞白血病 N HN O H3C N CH3 S NH O OH O O OH Raltitrexed thymidylate synthase inhibitor N N N O HN H HO HO HO pentostatin Adenosine deaminase inhibitor IV 治疗毛细胞白血病 O H2 N NH OH Hydroxycarbamide Ribonucleotide reductase inhibitor