We prepared a novel fluorous deoxy-fluorination reagent N,N-diethyl--difluoro-[3,5-bis(1H,1H,2H,2H-perfluorodecyl)benzyl]amine (1b) from 3,5-diiodobenzoic acid (3b) via N,N-diethyl-3,5-bis(1H,1H,2H,2H-perfluorodecyl)benzamide (2b) in four steps and used it for the fluorination of alcohols and diols. After the fluorination reactions, the isolation of the products and recovery of 2b was perfor...

In the production of biological effects such as vesication by bis-p-chloroethyl sulfide (mustard gas) it has been considered probable that inactivation of tissue enzymes is of foremost importance. In view of the reaction characteristics of bis-p-chloroethyl sulfide it has appeared likely that this inhibition is due to an alkylation reaction involving essential groups of the enzymes. Involvement...

The reactivities of the two cysteine thiol groups of calf thymus F3 histone were investigated using 5,5'-dithiobis-[2- nitrobenzoic acid], (DTNB). In isolated histone, both thiol groups were available for reaction. However, analysis of reaction profiles of native deoxyribonucleohistone, (DNH), in various solvent conditions, together with gel electrophoresis studies of DNH modified with DTNB, sh...

The synthesis of long-arm thiolated beads from beaded polyacrylamide ( $400 mesh, 10-37^ M diameter, 2,000 Dalton inclusion limit) is described. The long spacer arm, polyethylene glycol di(3-mercapto-propionate)(PEG-DMP) was i introduced via thioether formation with haloacetamidoethyl beads. The latter were prepared via the N-hydroxysuccinimide ester (NHS) after surveying a number of peptide co...

Thiolation of immunoglobulin G (IgG) with DL-N-acetylhomocysteinethiolactone, catalyzed by 2-pyridinealdoxime methiodide, incorporated new sulfur groups into IgG. Triaziquinone was subsequently conjugated to the sulfur groups. Triaziquinone-IgG complex retained the alkylating activity of the drug and the immunological activity of the antibody. The conjugation procedure was inhibited by the thio...

A bifunctional fluorescent alkylating agent, dibromobimane, has been used to stabilize a preexisting primary loop in myosin subfragment 1 (S-1). The crosslink achieved joins Cys-707 (called sulfhydryl group "SH1") of the 20-kDa domain (formerly called "20K" domain) with a thiol of the 50-kDa domain and seems to place the dibromobimane near the ATP-perturbable tryptophan.

Chemical modifications of the biotin carrier in pretargeted avidin–biotin radionuclide therapy may be of paramount importance for tuning the amount of the radioactivity delivered to cancer cells by labelled biotins. We report here the synthesis of a collection of new synthetic DOTA-constructs bearing two (+)-biotin molecules (bis-biotins), designed for the creation of multimeric Av units (tetra...

A thiol-terminated polyethyleneglycol (PEG)-paclitaxel (PTX) conjugate was synthesized and utilized to construct a novel drug delivery system with thiol-functionalized silica nanoparticles (SLNs) to improve the overall performance of PTX in liver cancer therapy. Drug loading was performed by coating the PTX conjugate on the surface of SLNs. The PTX-PEG/SLNs showed a binary responsive drug relea...

Chemotherapy failure remains a significant medical problem in the treatment of neoplastic disease and is thought to be due to many different factors including membrane transport, p-glycoprotein in multidrug resistance, glutathione and its related enzymes, topoisomerase II and DNA repair. Glutathione is a major constituent of non-protein thiol and participates in detoxification of chemotherapy a...