Part 1. 我們根據人類氨基肽酶P (Human Aminopeptidase P，簡稱hAMPP)水解bradykinin (一個會使血管擴張的物質)的過程中可能產生的四面體過渡狀態設計一系列結構類似於該過渡狀態的hAMPP抑制劑 (TH01~TH11) (圖十二)，並成功的將這一系列的化合物合成出來，並等待其活性性測試之後的結果。 另一方面，為了能夠對我們所合成出來的一系列化合物進行快速的活性測試以篩選出有抑制效果的化合物，我們也根據前人所使用的方法24合成出螢光檢測方法所需的substrate24 (化合物27，圖十四)，並等待其實驗操作條件的建立。 Part 2. 我們設計並合成出一系列ethacrynic acid (EA)的類似物作為人類麩胺基硫轉換酶 (hGST)的抑制劑 (TH52~TH55，圖七)，然後針對hGSTA2及hGSTM1兩不同類型的hGST測試其生物活性，並探討其化學結構與活性之間的關係。結果顯示TH52~TH55對hGSTA2及hGSTM1具有很明顯的選擇性，這四種抑制劑都是對hGSTM1有較好的抑制效果，其中又以苯環上有氯原子的TH52對hGSTM1的效果最好，IC50 = 5.5±2.6 μM，其於三個抑制劑在苯環上沒有任何氯原子及其他鹵素原子的存在，抑制效果非常不盡理想，因此我們認為在苯環上接上鹵素類的拉電子基可能會有助於提升其抑制效果，因此這一點可以成為我們以後設計此類型抑制劑時的一個依據。 Part 1. Human aminopeptidase P (hAMPP) is a metal-dependent enzyme and a member of proline-specific peptidase, which catalyzes the Xaa-Pro bond by cleaving the N-terminal residue at the C-terminus of peptide, such as bradykinin. The design and synthesis of potent peptide-type hAMPP tetrahedral transition-state analogue inhibitors such as TH01~TH11 is described. Furthermore, a fluorescent substrate used to analyze hAMPP activity through the theory of fluorescence resonance energy transfer (FRET) was successfully synthesized. Measurement of biological activity is currently underway. Part 2. A series of ethacrynic acid (EA)-based human glutathione-S-transferase (hGST) inhibitors, TH52~TH55, were synthesized, and their participation in inhibition of hGSTA2 and hGSTM1 was evaluated. Compounds TH52~TH55 selectively displayed potent inhibitory properties toward hGSTM1 but hGSTA2. Especially, TH52 was the most active compound against hGSTM1 with an IC50 of 5.5 ± 2.6 μM. These results suggested that substitution of electron-withdrawing groups in aromatic ring are clearly required for the enhancement of inhibitory property and provide a new way for inhibitor design in the future.
