2-Hydroxy-4-pentynoic acid (1) is a key intermediate towards 'clickable' polylactide which allows for efficient introduction of a broad range of pendant functional groups onto polymers from a single monomer via convenient 'click' chemistry with organic azides. The incorporation of various pendant functional groups could effectively tailor the physicochemical properties of polylactide. The repor...

Horseradish peroxidase (HRP) catalyzes the oxidative chemiluminescent reaction of luminol, and firefly luciferase catalyzes the oxidation of firefly D-luciferin. Here we report a novel substrate, 5-(5'-azoluciferinyl)-2,3-dihydro-1,4-phthalazinedione (ALPDO), that can trigger the activity of HRP and firefly luciferase in solution because it contains both luminol and luciferin functionalities. I...

The objective of this study was to determine whether nitric oxide (NO) is responsible for the vascular smooth muscle relaxation elicited by endothelium-derived relaxing factor (EDRF). EDRF is an unstable humoral substance released from artery and vein that mediates the action of endothelium-dependent vasodilators. NO is an unstable endothelium-independent vasodilator that is released from vasod...

A validated and sensitive spectrophotometric method is developed for the quantitation of nicorandil in pharmaceutical formulations. The method is based on the reduction of nitroxy ethyl group of nicorandil to carbonyl derivative and nitrite ion by Zn/NH4Cl. The nitrite ion undergoes diazotization with sulphanilamide in presence of HCl followed by coupling with N-(1-naphthyl) ethylenediamine dih...

A discussion of nitrosative deamination of cytosine 1 is presented that argues for the formation of 6 by diazotization of 1 to cytosinediazonium ion 2 and its electrostatic complex 3, dediazoniation to 4 <--> 5, and amide-bond cleavage to 6. The reaction channels available to 6 include hydrolytic deglycation to 3-isocyanatoacrylonitrile 7, water addition to carbamic acid 9 with the possibility ...

Two novel simple, precise and rapid spectrophotometric methods (Mehod A and Mehod B) are proposed for the determination of sulfamethaxazole (SFZ) using ferric chloride and potassium ferricyaide, sodium nitrite and resorcinol, as reagents. Method A is based reduction of Fe+3 by SFZ and Fe+2 produced forms complex with potassium ferricyanide to form a green colored chromogen having maximum absorp...

A number of derivatives of riboflavin and of 3-methyllumiflavin substituted in the 6 position have been synthesized starting with 6-nitro flavins, reduction to the 6-amino flavin, and diazotization, followed by reaction with the appropriate nucleophile. The absorption spectra, oxidation-reduction potentials, and the electron spin resonance spectra of the radical cationic forms of several of the...

This study aimed for the synthesis of new heterocyclic compounds incorporating sulfamoyl moiety suitable for use as antimicrobial agents via a versatile, readily accessible N-[4-(aminosulfonyl)phenyl]-2-cyanoacetamide (3). The 2-pyridone derivatives were obtained via reaction of cyanoacetamide with acetylacetone or arylidenes malononitrile. Cycloaddition reaction of cyanoacetamide with salicyal...

A competitive enzyme-linked immunosorbent assay (ELISA) was developed to quantify the amount of @-exotoxin from Bacillus thuringiensis in solution and to evaluate the ability of the antibodies to distinguish among various natural and synthetic compounds related to the 8-exotoxin. The &exotoxin was coupled to several proteins via glutaraldehyde, diazotization, and periodate procedures. The antib...

Surface-enhanced resonance Raman scattering (SERRS) has been used to establish a rapid and quantitative assay based on the diazotization coupling reaction for thyrotropin-releasing hormone (TRH). Ultrahigh sensitivity of this approach originates from two factors: changing TRH to an azo compound and the SERRS effect with the addition of silver nanoparticles (AgNPs) at 532 nm excitation wavelengt...