申请人:The Regents of the University of California
公开号:US05134232A1
公开(公告)日:1992-07-28
The invention discloses fluorescent chelator compounds that are especially useful to monitor and measure cytosolic concentrations of alkali metal cations such as Na.sup.+, K.sup.+, and Li.sup.+. The new compounds are comprised of: (1) crown ethers (that may or may not have substituent groups attached to the core carbons, but will always contain at least one core nitrogen) that are linked via the core nitrogen(s) to at least one (2) fluorophore that contains an additional heteroaromatic liganding center. In the currently preferred dye, SBFI, the core compound is crown ether 1,7-diaza-4,10,13-trioxacyclopentadecane and the heteroaromatic fluorophores are benzofurans that are linked to isophthalate groups. Selectivities for Na.sup.+ over K.sup.+ of about 20 are observed, resulting in effective dissociation constants for Na.sup.+ of about 20 mM against a background of 120 mM K.sup.+. Increasing [Na.sup.+ ] increases the ratio of excitation efficiency at 330-345 nm to that at 370-390 nm with emission collected at 450-550 nm, so that ratio fluorometry and imaging work at the same wavelengths as used with the well-known Ca.sup.2+ indicator fura-2. If the macrocyclic ring is increased in size to a 1,10-diaza-4,7,13,16-tetraoxacyclooctadecane, the chelators become selective for K.sup.+ over Na.sup.+. If the ring is decreased in size, for example to a 1,7-diaza-4,10-dioxacyclododecane, the chelators become selective for Li.sup.+ over Na.sup.+.
本发明揭示了荧光螯合物化合物,特别适用于监测和测量细胞质中碱金属阳离子(如Na.sup. +,K.sup. +和Li.sup. +)的浓度。新化合物由以下组成:(1)冠醚(可能具有或不具有连接到核心碳的取代基,但始终包含至少一个核心氮),通过核心氮与至少一个(2)荧光团连接,其中荧光团包含额外的杂环芳基配位中心。在目前首选的染料SBFI中,核心化合物是1,7-二氮代-4,10,13-三氧杂环十五烷,杂环芳基荧光团是连接到异苯二甲酸基团的苯并呋喃。观察到对Na.sup. +的选择性超过K.sup. +约20倍,因此在120 mM K.sup. +的背景下,对Na.sup. +的有效解离常数约为20 mM。增加[Na.sup. +]会增加在330-345 nm处的激发效率与在370-390 nm处的激发效率之比,发射在450-550 nm处收集,因此比例荧光测量和成像与众所周知的Ca.sup.2+指示剂fura-2使用相同的波长。如果将大环环增加到1,10-二氮代-4,7,13,16-四氧杂环八十一烷,则螯合剂对K.sup. +比Na.sup. +更具选择性。如果环的大小减小,例如到1,7-二氮代-4,10-二氧杂环十二烷,则螯合剂对Li.sup. +比Na.sup. +更具选择性。