The interaction of alkaloids with selected polyhaloquinone and polycyanoquinone n-acceptors was found to yield intensely coloured radical ions. This finding was developed into a sensitive spectrophotometric assay for alkaloids of general applicability and with adequate accuracy and precision. 7,7,8,8-Tetracyanoquinodimethane is used as the reagent.
Anwendung von rr-Acceptoren zur quantitativen Analyse von AlkaloidenAkaloide geben mit rr-Acceptoren vom Typ der Polyhalogenchinone und Polycyanochinone intensiv gefirbte Radikal-Anionen. Auf Grund dieser Reaktion wurde eine allgemein anwendbare, empfindliche photometrische Bestimmungsmethode fur Alkaloide entwickelt, die auf der Umsetzung mit 7,7,8,8-Tetracyanochinondimethan beruht.n-Acceptors, such as tetracyanoethylene (TCNE), 7,7,8,8-tetracyanoquinodimethane (TCNQ), chloranil and 2,3-dichloro-5,6-dicyanoquinone (DDQ) are known to yield charge-transfer complexes and radical ions with a variety of electron donors which include amines' -'). This donor-acceptor interaction has not been investigated hitherto for alkaloids as a group of n-electron donors which were recently demonstrated to participate in charge-transfer complexation with iodine4-'). Furthermore, relatively few previous publications concerned the analytical applications of this interaction, and were mainly centered on indoles and aromatic amines with TCNE'-'').
A novel series of coumarin-thiadiazole heterocycle derivatives was synthesized by the nucleophilic substitution reaction. The synthesized compounds were structurally verified by IR, 1 H NMR, 13 C NMR, mass spectra, and elemental analyses. to 42%, 45%, and 43% methyl green displacement, respectively. Out of the 60-cell line panel, the leukemia HL-60 cell line was the most susceptible to growth inhibition when treated with 14a, resulting in 61% growth, followed by the lung carcinoma cell line NCI-H522 showing 67% growth when treated with 9. Moreover, compound 10c had an IC 50 value of 24.9 μg/mL against the HepG-2 cell line.
K E Y W O R D Santitumor, coumarin, DNA binding, DNA cleavage, thiadiazole
A simple, accurate and rapid method for the quantitative determination of ten phenothiazine drugs in either the pure form or in pharmaceutical formulations is proposed. The method is based on the development of pink or violet products with N-bromosuccinimide in a strong sulphuric acid medium. The reaction is suggested to proceed via oxidation of the phenothiazine nucleus into a semiquinonoid radical. The wavelengths of maximum absorption range from 512 to 565nm. Molar absorptivities range from 6 x 103 to 20 x 103 1 mol-l cm-l. A linear correlation was found between absorbance (at the Am=.) and concentration. The resulting colours are well developed within 20-30min and are stable for at least 10h. Results of analyses of pure drugs and their dosage forms by the proposed method are in good agreement with those of the official BP 1980 and USP XX procedures.
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