Molecular Design of Nobel DNA Alkylating Agent at GG step

Nobel DNA 烷基化剂 GG 步骤的分子设计

• 批准号: 11680588
• 负责人: NAKATANI Kazuhiko
• 金额: $ 2.3万
• 依托单位: KYOTO UNIVERSITY
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1999
• 资助国家: 日本
• 起止时间: 1999 至 2000
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-11680588/
• 关键词: Guamine; Alkylation; Homo; GG配列; HOMO; DNA; インターカレーション; GG; 配列選択性; エポキシド

We have synthesized naphthopyranone epoxide from D-isoascorbic acid together with its three diastereoisomers. DNA alkylation of ODNs containing 5'XGT3' and 5'TGY3' by (11R, 13R)-epoxide, where X and Y are any nucleotide bases, occurred at all G residues except at G of 5'TGC3' sequence. In contrast, other three diastereoisomers showed only weak G alkylation activity. Differential ^1H NMR NOE of drug-G adduct confirmed the G-N7 alkylation at the epoxide carbon with concomitant S_N2 ring opening of the epoxide. Quantitative HPLC analysis of G alkylation efficiency by showed the order of G alkylation susceptibility as TGGT 【approximately equal】 CGT >> TGA > AGT > TGT >> TGC.The order was fully consistent with those reported for aflatoxin B_1 oxide and kapurimycin A_3, suggesting that the sequence selectivity observed for these DNA alkylating agents is not structure dependent but most likely due to the intrinsic property of DNA sequences. We found that the order of G alkylation susceptibility obtained completely matched with the calculated HOMO energy level of G-containing sequences. These results underscore that our drug is a unique molecular probe for ranking HOMO level of G-containing sequences by well-known G alkylation chemistry and suggests that the intercalation of charge neutral intercalators is a HOMO-controlled process.

我们以D-异抗坏血酸及其三个非对映异构体为原料合成了萘并吡喃酮环氧化物。含5 'XGT 3'和5 'TGY 3'的ODN被（11 R，13 R）-环氧化物（X和Y为任意核苷酸碱基）的烷基化反应发生在5 'TGC 3'序列中除G外的所有G残基上。相比之下，其他三种非对映异构体仅显示弱的G烷基化活性。药物-G加合物的差示1H NMR NOE证实了在环氧化物碳上的G-N7烷基化，伴随着环氧化物的S_N2开环。HPLC定量分析表明，G烷基化敏感性的顺序为TGGT>> TGA > AGT > TGT >> TGC，与文献报道的氧化黄曲霉毒素B_1和卡普雷霉素A_3的顺序完全一致。这表明对这些DNA烷基化剂观察到的序列选择性不是结构依赖性的，而很可能是由于DNA的内在性质序列的我们发现，得到的G烷基化敏感性的顺序与计算的含G序列的HOMO能级完全匹配。这些结果强调了我们的药物是一种独特的分子探针，用于通过众所周知的G烷基化化学对含G序列的HOMO水平进行排名，并表明电荷中性嵌入剂的嵌入是HOMO控制的过程。