75453-82-6Relevant articles and documents
Fiber Optic Biosensor for Cyclodiene Insecticides
Brummel, Kathleen E.,Wright, Jeremy,Eldefrawi, Mohyee E.
, p. 3292 - 3298 (1997)
Chlorendic caproic acid (CCA) was used to synthesize hexachlorocyclopentadienefluorescein (FL) and bovine serum albumin (BSA) conjugates. Anti-CCA antibodies (CCA-Abs), which were raised against BSA-CCA and immobilized on quartz fibers, bound FL-CCA selectively and reversibly. Fluorescence generated by evanescent excitation of the bound FL-CCA was used to monitor the binding event. The affinity of CCA-Abs for FL-CCA (KD = 1-9 nM) was calculated from the time courses of association and dissociation of FL-CCA. The cyclodiene insecticides chlordane, heptachlor, dieldrin, endrin, aldrin, and endosulfan competed with FL-CCA for binding to CCA-Abs and reduced fluorescence in a concentration-dependent manner with the following rank order: chlordane > heptachlor > dieldrin > aldrin > endosulfan. This fiber optic fluoroimmunosensor detects cyclodiene insecticides at the ppb level, has low cross-reactivity with γ-hexachlorocyclohexane, and does not detect (p,p'-dichlorodiphenyl)trichloroethane (DDT).
Fast diazaborine formation of semicarbazide enables facile labeling of bacterial pathogens
Bandyopadhyay, Anupam,Cambray, Samantha,Gao, Jianmin
supporting information, p. 871 - 878 (2017/05/17)
Bioorthogonal conjugation chemistry has enabled the development of tools for the interrogation of complex biological systems. Although a number of bioorthogonal reactions have been documented in literature, they are less ideal for one or several reasons including slow kinetics, low stability of the conjugated product, requirement of toxic catalysts, and side reactions with unintended biomolecules. Herein we report a fast (>103 M-1 s-1) and bioorthogonal conjugation reaction that joins semicarbazide to an aryl ketone or aldehyde with an ortho-boronic acid substituent. The boronic acid moiety greatly accelerates the initial formation of a semicarbazone conjugate, which rearranges into a stable diazaborine. The diazaborine formation can be performed in blood serum or cell lysates with minimal interference from biomolecules. We further demonstrate that application of this conjugation chemistry enables facile labeling of bacteria. A synthetic amino acid D-AB3, which presents a 2-acetylphenylboronic acid moiety as its side chain, was found to incorporate into several bacterial species through cell wall remodeling, with particularly high efficiency for Escherichia coli. Subsequent D-AB3 conjugation to a fluorophore-labeled semicarbazide allows robust detection of this bacterial pathogen in blood serum.
Arabinogalactan-folic acid-drug conjugate for targeted delivery and target-activated release of anticancer drugs to folate receptor-overexpressing cells
Pinhassi, Roy I.,Assaraf, Yehuda G.,Farber, Shimon,Stark, Michal,Ickowicz, Diana,Drori, Stavit,Domb, Abraham J.,Livney, Yoav D.
experimental part, p. 294 - 303 (2010/10/19)
Folic acid (FA) is a high affinity ligand (Kd = 0.1-1 nM) of folate receptors (FRs) responsible for cellular uptake of folates via receptor-mediated endocytosis. FRs are frequently overexpressed in malignant epithelial cells including ovary, brain, kidney, breast, colon, and lung. FR has emerged as a target for the differential-delivery of anticancer chemotherapeutics with several FA-linked therapeutic agents currently undergoing clinical trials. Here we show that by tethering both FA and the anticancer drug methotrexate (MTX) to arabinogalactan (AG), a highly branched natural polysaccharide with unusual water solubility, a targeted biomacromolecular nanovehicle is formed, which can differentially deliver a cytotoxic cargo into FR-overexpressing cells. Moreover, by linking MTX via an endosomally cleavable peptide (GFLG), we demonstrate a target-activated release mechanism. This FA-AG-GFLG-MTX drug conjugate displayed 6.3-fold increased cytotoxic activity to FR-overexpressing cells compared to their FR-lacking counterparts. These findings establish a novel FA-tethered polymeric nanoconjugate for the targeted delivery of antitumor agents into cancer cells overexpressing FR.
