Specific excitonic interactions in the aggregates of hyaluronic acid and cyanine dyes with different lengths of methine group

Photochemical & Photobiological Sciences : Official Journal of the European Photochemistry Association and the European Society for Photobiology
H Tobata, T Sagawa

Abstract

The absorption and circular dichroism (CD) spectra of three types of cyanine dyes with different lengths of methine group (3,3'-diethylthiadicarbocyanine iodide, DTDC; 3,3'-diethylthiacarbocyanine iodide, DTC; and 3,3'-diethylthiacyanine iodide, DTTHC) in an aqueous solution were compared with and without hyaluronic acid (HA), which has a helical structure. DTDC forms chiral H- and J-aggregates, whereas DTC and DTTHC are unable to form any aggregates. DTDC also forms H- and J-aggregates in the presence of sodium polyacrylate (PA) with a random-coil structure; however, the PA-DTDC aggregates exhibit no chirality. These results suggest that the chirality of HA-DTDC aggregates is induced by the helical structure of HA. In 2.4 vol% and 10 vol% methanol, HA-DTDC aggregates displayed different patterns of temperature dependence, whereas no aggregation was observed in 30 vol% methanol. The solubility of DTDC in a mixed solvent of water and methanol is generally improved by the addition of methanol, which prevents the aggregation of DTDC.

Citations

Feb 16, 2018·Photochemical & Photobiological Sciences : Official Journal of the European Photochemistry Association and the European Society for Photobiology·N Kaerkitcha, T Sagawa

❮ Previous
Next ❯

Related Concepts

Related Feeds

Cajal Bodies & Gems

Cajal bodies or coiled bodies are dense foci of coilin protein. Gemini of Cajal bodies, or gems, are microscopically similar to Cajal bodies. It is believed that Cajal bodies play important roles in RNA processing while gems assist the Cajal bodies. Find the latest research on Cajal bodies and gems here.

Attention Disorders

Attention is involved in all cognitive activities, and attention disorders are reported in patients with various neurological diseases. Here are the latest discoveries pertaining to attention disorders.