RESUMO
A classification system for 151 antibiotics exhibiting antitumor properties using thin layer chromatography (TLC) and bioautography was developed. TLC classification is based on mobility of the compounds in a solvent system using a certain adsorbent, rather than on misleading RF values. The solvent systems and conditions used are presented.
Assuntos
Antibióticos Antineoplásicos/classificação , Cromatografia em Camada Fina , Adsorção , Métodos , Testes de Sensibilidade Microbiana , Solubilidade , SolventesRESUMO
A rapid and simple method has been developed for the nondestructive distinction between aflatoxin B1 and the feed antioxidant, ethoxyquin. These two chemicals exhibit similar RF values in certain solvent systems and produce a similar bluish fluorescence under long UV (366 nm) radiation. The method involves the in situ generation of fluorescence spectra of the respective thin-layer chromatography spots. Since it is nondestructive, the method affords ancillary study of the separated aflatoxins.
Assuntos
Aflatoxinas/análise , Etoxiquina/análise , Quinolinas/análise , Animais , Embrião de Galinha , Cromatografia em Camada Fina , Espectrometria de Fluorescência , Raios UltravioletaRESUMO
The detection of alkylated bases at the nanogram level is reported. The reaction is based on two steps, first, chlorination of the bases and, secondly, spraying the chlorinated product with o-tolidine solution to give a dark blue color. The detection of nucleotides and nucleosides is also possible. The optimum conditions and the possible mechanism of the reaction are discussed.
Assuntos
Adenina/análise , Citosina/análise , Guanina/análise , Nucleosídeos/análise , Nucleotídeos/análise , Uracila/análise , Alquilação , Cloro , Cromatografia em Camada Fina , Indicadores e ReagentesRESUMO
A one-dimensional thin-layer chromatographic (TLC) method using a mixture of two solvents and commercially available silica gel plates to separate mixtures of alkylated guanines, adenines, uracils and cytosines is presented. RF values for the bases and the solvent systems used are listed. The addition of approximately 1 ml of ammonium hydroxide to the solvent has been found to prevent streaking and results in non-distorted developed spots. A mixture of 19 adenine and uracil bases was resolved on silica gel plates employing two-dimensional TLC. Chloroform-methanol (90:10) was used for the first dimension and chloroform-propanol (90:30) for the second.
