Paul Amrita, Mengji Rakesh, Chandy Olive Abraham, Nandi Surajit, Bera Manoranjan, Jana Avijit, Anoop Anakuthil, Singh N D Pradeep
Department of Chemistry, Indian Institute of Technology Kharagpur, 721302, West Bengal, India.
Org Biomol Chem. 2017 Oct 18;15(40):8544-8552. doi: 10.1039/c7ob02280h.
o-Hydroxycinnamate derivatives are well-known phototriggers for fast and direct release of alcohols and amines without proceeding through the cleavage of carbonate or carbamate linkages. Despite these unique features, o-hydroxycinnamates lack extensive applications in biological systems mainly because of their non-fluorescent nature. To overcome this limitation, we have attached a 2-(2'-hydroxyphenyl) benzothiazole (HBT) moiety, capable of rapid excited-state intramolecular proton transfer (ESIPT) to the o-hydroxycinnamate group. The ESIPT effect induced two major advantages to the o-hydroxycinnamate group: (i) large Stokes' shifted fluorescence (orange colour) properties and (ii) distinct fluorescence colour change upon photorelease. In vitro studies exhibited an image guided, photoregulated release of bioactive molecules by the o-hydroxycinnamate-benzothiazole-methyl salicylate conjugate and real-time monitoring of the release action.
邻羟基肉桂酸衍生物是众所周知的光触发剂，可在不经过碳酸酯或氨基甲酸酯键断裂的情况下快速直接释放醇类和胺类。尽管具有这些独特特性，但邻羟基肉桂酸在生物系统中的应用并不广泛，主要是因为它们具有非荧光性质。为了克服这一限制，我们将一个能够进行快速激发态分子内质子转移（ESIPT）的2-（2'-羟基苯基）苯并噻唑（HBT）部分连接到邻羟基肉桂酸基团上。ESIPT效应给邻羟基肉桂酸基团带来了两个主要优点：（i）大斯托克斯位移荧光（橙色）特性，以及（ii）光释放时明显的荧光颜色变化。体外研究表明，邻羟基肉桂酸-苯并噻唑-水杨酸甲酯共轭物能够实现图像引导的、光调节的生物活性分子释放，并能实时监测释放过程。
