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Specific Excitonic Interactions in the Aggregates of Hyaluronic Acid and Cyanine Dyes With Different Lengths of Methine Group

H Tobata, T Sagawa

Photochem Photobiol Sci. 2016 Mar;15(3):329-33.

PMID: 26815728

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.

Chemicals Related in the Paper:

Catalog Number Product Name Structure CAS Number Price
AP514738 3,3′-Diethylthiadicarbocyanine iodide 3,3′-Diethylthiadicarbocyanine iodide 514-73-8 Price
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