New photoremovable protecting groups for carboxylic acids with high photolytic efficiencies at near-UV irradiation. Application to the photocontrolled release of L-glutamate
New photoremovable protecting groups for carboxylic acids with high photolytic efficiencies at near-UV irradiation. Application to the photocontrolled release of L-glutamate
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DOI：
10.1002/cbic.200600111
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发表时间：
2006-11-01
期刊：
影响因子：
3.2
通讯作者：
Goeldner, Maurice
中科院分区：
文献类型：
--
作者：
Specht, Alexandre;Thomann, Jean-Sebastien;Goeldner, Maurice
本文报道了3-（4，5-二甲氧基-2-硝基苯基）-2-丁基酯（DMNP 8）的合成、光解性质及其在L-谷氨酸笼化反应中的应用。DMNP 8酯的高产率合成产生4：1苏型/反式非对映异构体混合物，其可通过HPLC分离。虽然这些酯在中性缓冲液中是稳定的，但在364 nm处的光解诱导了>= 95%的羧酸释放，L-谷氨酸盐形成的量子产率为0.26。L-谷氨酸的释放也可能通过双光子光解，在720 nm处的作用截面为0.17 GM。在350 nm处的激光光解在410 nm左右产生一个瞬态物种，这归因于一个quinidaci-nitro中间体，该中间体在亚毫秒的时间范围内（t（1/2）= 0.53 ms）衰变为更快的γ-L-谷氨酰苏式酯。考虑到这些酯的吸光度（λ（max）=350 nm; λ =4500），苏型DMNPB酯代表可以在近UV波长下有效光解的新的笼状基团。在原代培养的海马神经元上已经证明了L-谷氨酸的有效和快速的光解释放。
We report here the syntheses and the photolytic properties of 3-(4,5-dimethoxy-2-nitrophenyl)-2-butyl (DMNP8) esters as new photoremovable groups for carboxylic acids, and their use for the caging of L-glutamate. A high-yielding synthesis of the DMNP8 esters led to a 4:1 threo/erythro diastereomeric mixture, which could be separated by HPLC. While these esters were stable in neutral buffer, photolysis at 364 nm induced a >= 95 % release of the carboxylic acid, with a 0.26 quantum yield for L-glutamate formation. L-Glutamate release was also possible by two-photon photolysis with an action cross section of 0.17 GM at 720 nm. Laser photolysis at 350 nm generated a transient species at around 410 nm, attributed to a quinonoid aci-nitro intermediate that decayed in the submillisecond time range (t(1/2) = 0.53 ms) for the faster gamma-L-glutamyl threo-esters. Given the absorbance of these esters (lambda(max)=350 nm; epsilon=4500), the threo DMNPB esters represent new caging groups that can be efficiently photolyzed at near-UV wavelengths. An efficient and rapid photolytic release of L-glutamate has been demonstrated on hippocampal neurons in primary culture.