14997-58-1Relevant articles and documents
Naphthalimide based fluorescent organic nanoparticles in selective sensing of Fe3+and as a diagnostic probe for Fe2+/Fe3+transition
Sarkar, Deblina,Chowdhury, Monalisa,Das, Prasanta Kumar
, p. 494 - 507 (2021)
Fluorescent organic nanoparticles (FONPs) have attracted considerable attention as a practical and effective platform for sensing and imaging applications. The present article delineates the fabrication of FONPs derived from the naphthalimide based histidine appended amphiphile, NID. The self-assembly of NID in 99 vol% water in DMSO led to the formation of FONPs through J-type aggregation. Aggregation-induced emission (AIE) was observed due to the pre-associated excimer of NID with bluish green emission at 470 nm along with intramolecular charge transfer (ICT). The emission of NID FONPs was utilized for selective sensing of Fe3+ and bioimaging of Fe3+ inside mammalian cells. The fluorescence intensity of the FONPs was quenched with the gradual addition of Fe3+ due to the formation of a 1?:?1 stoichiometric complex with the histidine residue of NID. The morphology of the FONPs transformed from spherical to spindle upon the complex formation of NID with Fe3+. The limit of detection (LOD) of this AIE based turn-off chemosensor for Fe3+ was found to be 12.5 ± 1.2 μM having high selectivity over other metal ions. On the basis of the very low cytotoxicity and selective sensing of Fe3+, NID FONPs were successfully employed for bioimaging of Fe3+ ions through fluorescence quenching within mammalian cells (NIH3T3, B16F10). Considering the varying oxidative stress inside different cells, NID FONPs were used for detecting Fe2+ to Fe3+ redox state transition selectively inside cancer cells (B16F10) in comparison to non-cancerous cells (NIH3T3). Selective sensing of cancer cells was substantiated by co-culture experiment and flow cytometry. Hence, NID FONPs can be a selective diagnostic probe for cancer cells owing to their higher H2O2 content. This journal is
Synthesis method of N-carbobenzoxy-L-histidine
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Paragraph 0047; 0055; 0058-0063; 0067-0071; 0074-0079, (2021/06/06)
The invention provides a synthesis method of N-carbobenzoxy-L-histidine, which comprises the following steps: step S1, enabling N-carbobenzoxy succinimide to react with L-histidine, so as to generate dicarbobenzoxy-L-histidine; and step S2, removing carbobenzoxy on an imidazolyl group in the bis (carbobenzoxy)-L-histidine, so as to obtain the N-carbobenzoxy-L-histidine. According to the synthesis method disclosed by the embodiment of the invention, N-benzyloxycarbonyloxy succinimide is used for replacing benzyl chloroformate, so that the problems that an intermediate is very sticky and is difficult to purify are solved; furthermore, the intermediate obtained by the first-step reaction is good in quality and free of unnecessary byproducts, and the second-step reaction can be carried out without purification of the first-step product, so that the process is simplified; moreover, when the carbobenzoxy group on the imidazolyl group is removed in the second step, ammonia gas is creatively adopted to replace common potassium hydroxide, sodium ethoxide and the like, the reaction condition is mild, removal of the alpha-amino protecting group can be avoided, and the problem of destroying the optical rotation of the product is avoided.
PH-sensitive polymeric micelles for drug delivery
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Page/Page column 5; 6, (2008/06/13)
Mixed micelles containing poly(L-histidine)-poly(ethylene glycol) block copolymer and poly(L-lactic acid)-poly(ethylene glycol) block copolymer are a pH-sensitive drug carrier that release the drug in an acidic microenvironment, but not in the blood. Since the microenvironment of solid tumors is acidic, these mixed micelles are useful for treating cancer, including those cancers exhibiting multidrug resistance. Targeting ligands, such as folate, can also be attached to the mixed micelles for enhancing drug delivery into cells. Methods of making poly(L-histidine), synthetic intermediates, and block copolymers are also described.
