新型TTDA-β-GP、4-(R)-DPPO-TTDA配位子及其鑭系、鋅(III)金屬錯合物之合成及物化特性研究

Synthesis and Physicochemical Characterization of the Novel TTDA-β-GP and 4-(R)-DPPO-TTDA and Their Complexes with Lanthanides(III) and Zn(II) ions

許雅雯(Ya-Wen Hsu)

指導教授 ： 王雲銘

高雄醫學大學/生命科學院/醫藥暨應用化學研究所/碩士(2004年)

摘要

利用鋅金屬交換來研究[Gd(TTDA-β-GP)]–與半乳喃醣酵素(β-galactosidase, β-gal)反應前後之動力學穩定度。由結果顯示[Gd(TTDA-β-GP)]-及[Gd(TTDA-β-GP)]–+2.4 nM β-gal對Zn2+有足夠動力學穩定性。利用17O-NMR測定Dy(III)金屬離子誘導水中17O核種之化學位移變化(d.i.s.)，求得[Gd(TTDA-β-GP)]–與半乳喃醣酵素反應前後之內層水分子變化，結果顯示其與酵素反應後，內層水分子增加33%。利用400MHz核磁共振光譜儀在25°C下，測量[Gd(TTDA-β-GP)]–與半乳喃醣酵素反應前後之縱向弛緩時間(longitudinal relaxation time，T1)，由此結果發現，[Gd(TTDA-β-GP)]–加入的酵素濃度愈高，反應時間愈久，表示半乳喃醣酵素切割愈多，故其T1值下降愈多。利用400MHz的17O核磁共振光譜儀，求得釓金屬錯合物之弛緩率(1/T1, 1/T2)和化學位移，進行數據逼近(data fitting)，可計算出釓金屬錯合物之內層水分子交換速率(kex)及分子轉動相關時間。[Gd(TTDA-β-GP)]–之kex值為125*10^6s–1，與 [Gd(TTDA)(H2O)]2-(146*10^6 s–1)類似，而遠比[Gd(DTPA)(H2O)]2- (3.03*10^6 s–1)高很多。而[Gd(TTDA-HE)(H2O)1.2]–之kex值為32.2*10^6 s–1，明顯比[Gd(TTDA)(H2O)]-低很多。在分子轉動相關時間方面，[Gd(TTDA-HE)(H2O)1.2]–與[Gd(TTDA)(H2O)]2–類似，明顯比[Gd(TTDA-β-GP)(H2O)0.8]–小很多。將[Gd(TTDA-β-GP)(H2O)0.8]–與[Gd(TTDA-HE)(H2O)1.2]–及[Gd(TTDA)(H2O)]2–做比較可發現，將中間的羧酸基(carboxyl group)取代成半乳喃醣官能基(galactopyranose group)，分子量增加故其值增加。將加入及未加入酵素反應之釓金屬錯合物分別利用磁振造影掃描得到影像，由影像得知未加入酵素前，影像是較暗的，而與酵素反應的影像明顯信號強度增強，二者有顯著的對比，信號強度增加82.35%。由此磁振造影之影像更可證明[Gd(TTDA-β-GP)]-為具有生物活性或酵素可切割的磁振造影對比劑。

關鍵字

具生物活性對比劑 ； 血池對比劑

並列摘要

The kinetic stability of [Gd(TTDA-β-GP)]– chelate containing phosphate buffer and ZnCl2 in the presence and absence of β-gal was studied by transmetallation with Zn(II). The stability toward Zn2+ transmetallation of [Gd(TTDA-β-GP)]–in the presence and absence of β-gal is less than that of [Gd(DTPA)]2– but is significantly higher kinetically stable than that of [Gd(DTPA-BMA)]. The number of inner-sphere water of [Gd(TTDA-β-GP)]–in the presence and absence ofβ-galactosidase was obtained, through the Dy(III)-Induced 17O water NMR shifts experiments. The number of inner sphere water molecule was significantly decreased (about 33%) in the presence ofβ-gal. The effect of the presence of β-gal cleavage the galactopyranose group from the [Gd(TTDA-β-GP)]–chelate on the spin-lattice relaxation time (T1) was assessed by 400 MHz NMR spectroscopy. The 17O NMR relaxation rates and angular frequencies of the Gd(III) complex solutions, 1/T1and 1/T2 of the acidified water reference, 1/T1A and 1/T2A were measured at 9.4 T. The accurate estimation of values for [Gd(TTDA-β-GP)(H2O)0.8]–, [Gd(TTDA-HE)(H2O)1.2]– and [Gd(TTDA)(H2O)]– are 125*10^6, 32.2*10^6 and 146*10^6 s-1, respectively. The values of [Gd(TTDA-β-GP)(H2O)0.8]–is significantly higher than those of [Gd(TTDA-HE)(H2O)1.2]?{ and [Gd(DTPA)]2–but lower than that of [Gd(TTDA)(H2O)]2–. The ?豩 value of [Gd(TTDA-HE)(H2O)1.2]–is similar to that of [Gd(TTDA)(H2O)]2– and is significantly lower than that of [Gd(TTDA-β-GP)(H2O)0.8]–. From the higher values for [Gd(TTDA-β-GP)(H2O)0.8]–compared to [Gd(TTDA)(H2O)]2– and [Gd(TTDA-HE)(H2O)1.2]–indicate that the replacement of the middle carboxylate group by a galactopyranose group increases the value. The MR imagings of [Gd(TTDA-β-GP)]– solutions placed in 5 mm NMR tube in the presence and absence of β-gal. The enhancement results of enzymatic cleavage of [Gd(TTDA-β-GP)]– indicated that the enhancement (82.35%) was significantly higher than before the galactopyranose residue removed.

並列關鍵字

TTDA-β-GP ； 4-(R)-DPPO-TTDA

參考文獻

參考文獻

1. H. Gries, H. Miklautz, Physiol. Chem. Phys. Med. NMR 1984, 16, 105.

2. H. J. Weinmann, R. C. Brasch, W. R. Press and G. E. Wesbey, Am. J. Roentg. 1984, 142, 619.

3. G. Vittadin, E. Felder, P. Tirone and V. B. Lorusso, Invest. Radiol. 1988, 23, 246.

4. R. B. Lauffer, W. F. Grief, D. D. Stark, A. C. Vincent, S. Saini, V. J. Wedden and T. J. Brady, J. Comput. Assist. Tomogra. 1985, 9, 431.