Cryptocyanine

Description

Cryptocyanine is a fluorescent dye widely used in biomedicine for various applications. It can be utilized to label and track cells, proteins, and biomolecules in live cell imaging studies. Additionally, Cryptocyanine is employed in the detection and imaging of specific diseases, including cancer, due to its high selectivity and sensitivity.

Chemical Properties

1,1'-DIETHYL-4,4'-CARBOCYANINE IODIDE is dark green fine crystalline powder

Uses

Organic dye, soluble, used as a chemical shutter in laser operation.

Uses

Suitable as laser dye

Definition

1,1'-DIETHYL-4,4'-CARBOCYANINE IODIDE is a cationic C3-cyanine type compound with 1-ethylquinolin-4-yl groups at both ends.

Reactions

The putative mitochondria-targeted cryptocyanine (Mito-CCy) and a non-targeted cryptocyanine (CCy) control were synthe- sized as outlined in Figure 1. Briefly, the synthesis entailed the alkylation of 4-methylquinoline with 4-bromomethylbenzoic acid to yield 3, which was further reacted with N,N′-diphenyl- formamidine and acetic anhydride to produce 2. Extension of the π-conjugated system 2 with 3 and triethylamine (TEA) re- sulted in cryptocyanine 1. The amide-linked target compound, Mito-CCy, was obtained from 1 by reacting with (PPh3+(CH2)2NH2)Br− in the presence of 2-(1H-9-azobenzo-tri- azole-1-yl)-1,1,3,3-tetramethylammonium hexafluorophos- phate (HATU), diisopropylethylamine (DIPEA) and TEA in N,N-dimethylformamide (DMF). CCy, an analogue lacking the TPP unit, was prepared using an analogous procedure. Both Mito-CCy and CCy and gave 1H NMR and 13C NMR spectral and ESI-MS analytical data consistent with their proposed structures.

Figure 1. Synthesis of Mito-CCy and CCy. (i) Triphenylphosphine, acetonitrile, reflux, 24 h, 88%; (ii) 4-(bromomethyl)benzoic acid, acetonitrile, 110 °C, 6 h, 72%; (iii) N,N′-diphenylformamidine, acetic anhydride, 150 °C, 1 h, 87%; (iv) 3, TEA, dichloromethane, 25 °C, 24 h, 48%; (v) propylamine, HATU, TEA, DIPEA, DMF, r.t., 24 h, 32%; (vi) 4, HATU, TEA, DIPEA, DMF, r.t., 24 h, 35%.

storage

Store at -20°C away from light, under an inert gas atmosphere (e.g. nitrogen) to prevent oxidative degradation. Repeated freeze-thaw cycles or high temperatures (>75°C) may cause decomposition.

References

[1] Jung, Hyo Sung, et al. “A Mitochondria-Targeted Cryptocyanine-Based Photothermogenic Photosensitizer.” Journal of the American Chemical Society, 139 29, 2017, pp. 9972–78, https://doi.org/10.1021/jacs.7b04263.