d,l-型環丁基丙烯氨圬鎝氧錯合物晶體分解反應之研究
d,l-型環丁基丙烯氨圬鎝氧錯合物晶體分解反應之研究
蔡長書
慈濟技術學院放射技術系
摘 要
在較高倍率掃描式電子顯微照相觀察下，鎝氧環丁基丙烯氨圬(99Tc(V)O-d,l-CB-PAO )單晶原為細長棒狀結晶，因不穩定分解產生團縮或蛀洞，晶面出現皺折或不規則碎裂。而未長晶之前已變黑之母液乾燥物，或已破壞分解之99Tc(V)O-d,l-CB-PAO 晶體，經由 1H-NMR 核磁共振光譜測試，只發現一較強的溶劑波峰(solvent peak) 吸收，可推測錯合物可能分解產生順磁性的 TcO2 之故。13C-NMR 核磁共振光譜結果亦知其不 同 環 境 碳種類(carbon style )僅有一組，已小於未分解前99Tc(V)O-d,l-CB-PAO 理 論 上 應 有 的 十 二 組 不 同 環 境 碳種類，顯示其立體化學結構亦已改變。另由紫外光-可見光光譜之測定，99Tc(V)O-d,l-CB-PAO 單晶可能由於水解或自身氧化還原，而分解產生游離態過鎝酸根離子(free 99TcO4- )和游離態的d,l-CB-PAO配位子或某些水 溶 性 的未知新物種。此一實驗結果與文獻報導， 99mTc(V)O-d,l-HM-PAO 配 劑 後，有 體 外 不 穩 定 分 解 現 象 及 進 入 血 腦 障 壁 後 因 親 脂性 變 為 水 溶 性 物 種 而 滯 腦，有 相 同 現象與特性。因而，初步可推論99mTc(V)O-d,l-CB-PAO 與 99mTc(V)O-d,l-HM-PAO 有 類 似 的 體 內 滯 腦 機 制。
關鍵字：鎝(V)氧-環丁基丙烯氨圬錯合物，配位子，單晶，水 溶 性，親 脂性
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Study on the Decomposition of Single Crystal of 99Tc(V)O-d,l-CB-PAO Complex
Chang-Shu Tsai
Department of Radiological Technology Tzu-Chi College of Technology
ABSTRACT
The single crystal of 99Tc(V)O-d,l-CB-PAO was observed under scanning electron microscope(SEM) with an enlargement of ×20-200,000, and was found the well-defined bar-like crystal. Due to the in vitro instability of 99Tc(V)O-d,l-CB-PAO complex, SEM micrographs of decomposed fractions clearly revealed some distinct crystal characters: ill-defined irregular bars stunk together into amorphous looking materials. The black amorphous 99Tc(V)O-d,l-CB-PAO fractions which sampling from the dried mother liquor were measured by using 1H-NMR spectroscopy. It was found that one strong solvent absorption peak displays only. This may support that 99Tc(V)O-d,l-CB-PAO has decomposed and produced a paramagnetic TcO2 species. In addition, 13C-NMR spectroscopy of decomposed 99Tc(V)O-d,l-CB-PAO displays only one kind of carbon type, but that of undecomposed 99Tc(V)O-d,l-CB-PAO should exist 12 kinds of C type theoretically. It appears that the stereochemical structure of 99Tc(V)O-d,l-CB-PAO has clearly been changed. According to results of UV-vis spectroscopy, the single crystal of 99Tc(V)O-d,l-CB-PAO has been decomposed and it may produce free 99TcO4-, isolated d,l-CB-PAO ligand and new unknown hydrophilic species by means of hydrolysis or self-oxidation and reduction.
Base on the experimental results shown above with those found in the literatures, one notices that in vitro instability of 99mTc(V)O-d,l-CB-PAO was observed similarly compared to commercial 99mTc(V)O-d,l-HM-PAO now in clinic use. Extensive studies have confirmed that the lipophilic 99mTc(V)O-d,l-HM-PAO complex is possible to be metabolized and changed into hydrophilic species when crossing the blood-brain barrier(BBB). Therefore, it seemed that in vivo brain uptake and retention mechanism of 99mTc(V)O-d,l-CB-PAO is similar with that of 99mTc(V)O-d,l-HM-PAO.
Key words: 99Tc(V)O-d,l-CB-PAO complex, ligand, single crystal, hydrophilic, lipophilic
