Preparation of monomethine cyanine dyes as noncovalent labels for nucleic acids

Abstract

By condensation of quaternary benzothiazolium, quinolinium and acridinium salts having an active methyl group with 1-(3-bromopropyl)-4-chloroquinolinium or 1-(3-bromo-2-hydroxypropyl)-4-chloroquinolinium salts in the presence of a basic agent such as triethylamine, 8 asymmetric and symmetric monomethine cyanine dyes bearing 3-bromopropyl substituent with one or two positive charges, were synthesized. Additionally, two of the dyes were quaternized with pyridine, and monomethine cyanines with two and three positive charges are prepared. Most of the dyes showed high molar absorptivity (70 000±100 000 l mol À1 cm À1 ). The acridinium dyes showed broad peaks with lower intensity of 30 000 l mol À1 cm À1 . In the presence of nucleic acid in aqueous solutions, a strong enhancement of thē uorescence of these new dyes was observed. #

New Cyanine–Oligonucleotide Conjugates: Relationships between Chemical Structures and Properties

“…[32][33][34][35][36][37][38][39][40][41][42][43][44][45][46] The interactions of a few other cyanines, including thiocyanine and quinocyanines, with nucleic acids have been investigated and have shown an increase in the fluorescence signal. [58,59] Following this information and our previous results obtained with TO, we chose to synthesize a series of monomethine cyanines and to attach them to various positions on ODNs involving the four nucleic bases.…”

Noncovalent Labeling of Biomolecules with Red and Near- Infrared Dyes

“…As with squarylium dyes, the fluorescence efficiency of the conformationally flexible cyanine counterparts is greatly enhanced upon immobilization in complexes with biomolecules. Polycationic cyanine derivatives including 9-11 have been synthesized for a strong binding to nucleic acids [19][20][21][22][23][24][25]. On the other hand, dyes 12-14 with a net charge of -1 show strong interaction with proteins [26][27][28][29][30].…”

Design, Synthesis and Biological Evaluation of Novel Rapamycin Benzothiazole Hybrids as mTOR Targeted Anti-cancer Agents

“…29) Next, benzothiazolium salts (12a-e, 13a-c) were obtained by alkylation of 11 with dimethylsulfate and diethylsulfate under reflux for 10 h, respectively. 30) 43-O-(2-Bromoethyl)rapamycin (6) was prepared with rapamycin and side chain trifluoromethanesulfonate, followed by treating with sodium azide to give 43-O-(2-azidoethyl)- Chart 1 rapamycin (7) according to literature. 31) The product (8) was obtained from (7) in a similar manner as described for the preparation of compound (3).…”

“…Yields: 55-83%. 30) General Procedure for the Preparation of Compounds 4a-e The 43-aminorapamycin (0.2 g, 0.2 mmol) was dissolved in 10 mL of acetonitrile and then added dropwise to a solution of 10 mL of acetonitrile containing of Et 3 N (0.2 mL) and side chains 12 (0.66 mmol) at 25°C, and the mixture was stirred for 1 h. The mixture was quenched with a saturated NaHCO 3 solution (100.0 mL) and diluted with dichloromethane. Two phases were separated and the organic phase was washed with brine, the organic phase was then collected and dried overnight over anhydrous Na 2 SO 4 .…”