申请人:Nycomed Imaging AS
公开号:US05530140A1
公开(公告)日:1996-06-25
The invention provides novel persistent free radicals useful in Overhauser MRI being triarylmethyl radicals having as at least one aryl group a group of formula ##STR1## (wherein each X which may be the same or different is an oxygen or sulphur atom or a group CO or S(O).sub.n, (where n is 1 to 3) with the proviso that at least one group X is a sulphur atom or a S(O).sub.n group; R.sup.1 is a hydrogen atom or group of formula --M, --XM, --X--Ar.sup.2, or --Ar.sup.2 where M is a water solubilizing group, and Ar.sup.2 represents a 5-10 membered aromatic ring optionally substituted by a water solubilizing group M; and each of the groups R.sup.7, which may be the same or different, is a hydrogen atom, or a hydrocarbon group or a water solubilizing group M, or two groups R.sup.7 together with the atom to which they are bound represent a carbonyl group or a 5 to 8 membered cycloalkylidene, mono- or di-oxacycloalkylidene, mono- or di-azacycloalkylidene or mono- or di-thiacycloalkylidene group optionally with the ring attachment carbon replaced by a silicon atom, and R.sup.7 where it is other than hydrogen, is optionally substituted by a hydroxyl group, an optionally alkoxylated, optionally hydroxylated acyloxy or alkyl group or a water solubilizing group M)). The novel radicals have good stability, long relaxation times and good relaxivity.
本发明提供了一种新型的持久自由基,适用于Overhauser MRI,其为三芳基甲基自由基,其中至少一个芳基团为以下公式的一个团 ##STR1## (其中每个X,可以相同或不同,为氧或硫原子或CO或S(O).sub.n(其中n为1至3),但至少一个X为硫原子或S(O).sub.n团;R.sup.1为氢原子或式--M、--XM、--X--Ar.sup.2或--Ar.sup.2的一种,其中M为水溶解基团,Ar.sup.2表示一个5-10成员的芳香环,可选地被水溶解基团M取代;每个R.sup.7,可以相同或不同,为氢原子、烃基团或水溶解基团M,或两个R.sup.7基团与它们所结合的原子一起表示一个羰基团或5-8成员的环烷基亚烷基、单-或双-氧杂环烷基亚烷基、单-或双-氮杂环烷基亚烷基或单-或双-硫杂环烷基亚烷基,可选地,环附着碳原子被硅原子取代,其中R.sup.7如果不是氢原子,则可被羟基基团、可选烷氧基化、可选羟基化的酰氧基或烷基团或水溶解基团M取代)。这些新型自由基具有良好的稳定性、长的弛豫时间和良好的弛豫度。