Synthesis and Characterization of a Macrocyclic Near-Infrared Optical Scaffold

Abstract

Macrocyclization of a bioactive peptide with a bifunctional near-infrared fluorescent optical probe gives a compound that retained the receptor binding affinity of the peptide and the photophysical properties of the optical probe. The robust nature of the new compound provides a structural framework for optimizing the activity of bioactive molecules and for monitoring chemical or biological processes in vivo and in vitro by near-infrared optical methods.

Smart nanoparticles improve therapy for drug-resistant tumors by overcoming pathophysiological barriers

“…The micelles were composed of a pHresponsive diblock polymer and a polymeric prodrug of DOX ( Figure 3A and 3B). The diblock copolymer was functionalized with Cypate, an NIR dye, for photothermal conversion in the NIR region [53] . At physiological pH (ie, 7.4), the micelles formed a compact structure with a particle size of approximately 30 nm, allowing prolonged circulation in the blood and passive tumor targeting.…”

Near‐Infrared Dichromic Fluorescent Carbocyanine Molecules

“…The weak signal may account for the omission of the blue-shifted peaks in previous reports of the fluorescence properties of these compounds. [7][8][9][10] Upon conjugation of the symmetrical dye cypate with a peptide, the resulting nonsymmetrical cypate-peptide conjugate 5 exhibited a 45 % increase in the level of the 700-nm emission band (relative to cypate), albeit still lower than the 82 % obtained with 3 and 4. Although the 100-nm blue-shifted emission peak could indicate the elimination of a methine bond from the heptamethine structure, [11] it is unlikely that the emission band at 700 nm resulted from the formation of lower homologues (such as tri-or pentamethines) of cypate or ICG, which typically have similar fluorescence lifetimes of cypate at 800 nm (namely, 0.86 ns in dimethyl sulfoxide, DMSO).…”

“…In previous studies, we found that the two gemdimethyl groups in symmetrical cypate showed a singlet upfield. [8] However, the corresponding peak for nonsymmetrical 4 splits into two singlets. In addition, the vinyl protons at d = 6-7 ppm, which correspond to H 1 1 , H 1 3 , H 1 5 , and H 1 7 , are doublets in cypate but distorted in 4.…”

Dye‐Modified and Photoswitchable Macrocycles by Multiple Multicomponent Macrocyclizations Including Bifunctional Building Blocks (MiBs)

“…Very recently Achilefu and co-workers [4] reported bifunctionalized near-infrared (NIR) dyes like 1 which appear amenable for our MIB-approach due to the two carboxylic acid moieties. NIR dyes are most suitable bioprobes because they absorb at wavelengths of minimal interference with biological tissues.…”