Interestingly, only the D‐form of firefly luciferin produces light by luciferin–luciferase (L–L) reaction. Certain firefly luciferin analogues with modified structures maintain bioluminescence (BL) activity; however, all L‐form luciferin analogues show no BL activity. To this date, our group has developed luciferin analogues with moderate BL activity that produce light of various wavelengths. For in vivo bioluminescence imaging, one of the important factors for detection sensitivity is tissue permeability of the number of photons emitted by L–L reaction, and the wavelengths of light in the near‐infrared (NIR) range (700–900 nm) are most appropriate for the purpose. Some NIR luciferin analogues by us had performance for in vivo experiments to make it possible to detect photons from deep target tissues in mice with high sensitivity, whereas only a few of them can produce NIR light by the L–L reactions with wild‐type luciferase and/or mutant luciferase. Based on the structure–activity relationships, we designed and synthesized here a luciferin analogue with the 5‐allyl‐6‐dimethylamino‐2‐naphthylethenyl moiety. This analogue exhibited NIR BL emissions with wild‐type luciferase (λ_max = 705 nm) and mutant luciferase AlaLuc (λ_max = 655 nm).

中文翻译：

---

与野生型和突变型荧光素酶反应的近红外萤火虫荧光素类似物的发展。

有趣的是，只有萤火虫萤光素的D型通过萤光素-萤光素酶（L-L）反应发光。某些萤火虫萤光素类似物具有修饰的结构，可保持生物发光（BL）活性；但是，所有L形式的萤光素类似物没有BL活性。迄今为止，我们的小组已经开发了具有中等BL活性的荧光素类似物，可产生各种波长的光。对于体内生物发光成像，检测灵敏度的重要因素之一是L–L反应发射的光子数量的组织渗透性，并且近红外（NIR）范围（700–900 nm）的光波长为最适合此目的。我们提供的一些NIR荧光素类似物可用于体内实验，从而可以高灵敏度地检测小鼠深层靶组织中的光子，而其中只有少数能够通过与野生型荧光素酶的L–L反应产生NIR光和/或突变体荧光素酶。根据结构-活动关系，我们在这里设计并合成了具有5-烯丙基-6-二甲氨基-2-萘基萘部分的荧光素类似物。该类似物通过野生型萤光素酶表现出NIR BL发射（λ_最大= 705纳米）和突变荧光素酶AlaLuc（λ_最大= 655纳米）。