Y on the fluorescent indomethacin conjugates. Indomethacin Conjugates of NIR Fluorophores. Conjugation of a nile blue dye with all the carboxylic acid moiety of indomethacin tethered by means of a PEG4 linker afforded compound 65 (ex = 618 nm, em = 670 nm), a perchlorate salt, which was identified as a poor COX-2 inhibitor (Table 3). A total loss of COX inhibitory activity was observed with all the Cy5 conjugate 66. Interestingly, the Cy7 conjugate 67 inhibited COX-2 with poor potency, whilst inhibitory activity but lack of selectivity was observed with the NIR641 conjugate (68), a chloride salt. No substantial COX-2 inhibition was discernible together with the ethyl- or propyldiamide-linked indomethacin conjugates of NIR664, such as compounds 69 and 70, respectively. Nonselective COX inhibition was observed with all the piperazine-linked conjugate 71, an inner salt (zwitterion). Nevertheless, a total loss of COX activity was documented together with the higher alkyl homologues (72, 73). A equivalent loss was observed with the NIR667 conjugates 74-78 (chloride salts). Conjugation of indomethacin with NIR700, an inner salt, afforded the selective COX-2 inhibitor 79 (ex = 710 nm, em = 731 nm), which contained an n-butyldiamide linker. When the length with the linker was increased, conjugates 80-81 showed a dramatic loss of COX-2 inhibitory activity. Interestingly, a poor potency was achieved when the n-butyl linker was replaced by a phenylene-alkyl hybrid linker in compound 82, and no COX-2 inhibition was observed using the NIR782 or IRDyederivatives, compounds 83 and 84, respectively. A comparable lack of activity was observed with DOTA-, Eu-Quinoline(F)-DOTA-, Eu-Quinoline(CH3)-DOTA-, or Gd-DOTA-derivatives (compounds 85-106), even at incredibly high concentrations (Table four). As a result, conjugation of indomethacin using a zwitterionic fluorophore tethered by means of an n-butyldiamide linker is most suitable to achieve COX-2 inhibitory activity. Hugely polar organic functional groups, like DOTA, or its analogous lanthanide chelators, will not be suitable for COX-2 inhibitory activity from the conjugates. Fluorescent Conjugates of Miscellaneous NSAIDs and COXIBs. Lack of isoform selectivity or complete loss of COX-2 inhibitory activity was normally observed with fluorescent conjugates of NSAIDs and COXIBs apart from indomethacin (Table five). For example, the iodoindomethacin-5-ROX conjugates 107 and 109 showed no COX-2 selectivity.61098-37-1 manufacturer A complete loss of COX inhibitory activity was observed with the 5-ROX or NIR664 conjugates 108, 110, and 111.Biotin NHS In stock We synthesized O-des-methyl- or 2-des-methyl-indomethacin-5ROX conjugates 112 and 113, which were selective COX-2 inhibitors.PMID:33630469 Having said that, the 2-des-methyl-, N-des-4-chlorobenzoyl-, or N-4-chlorobenzyl-indomethacin and 5- or 6-ROX conjugates 114-117, containing an n-butyldiamide linker, showed no COX-2 inhibition. A loss of COX-2 inhibitory activity was also observed with fluorescent derivatives of reverse-indomethacin, 118-122. An exception was identified together with the reverseindomethacin-NIR700 conjugate (123), which exhibited selective COX-2 inhibition with a moderate potency. A total loss of COX-2 inhibitory activity was observed with the majority of fluorescent derivatives of celecoxib, flurbiprofen,dx.doi.org/10.1021/bc300693w | Bioconjugate Chem. 2013, 24, 712-Bioconjugate Chemistry Table five. In Vitro Purified COX-1 and COX-2 Enzyme Inhibition Assay Data of Compounds 107-ArticleaIC50 values were determined as described in Experimental Procedures. Assays have been run in.