52589-82-9Relevant academic research and scientific papers
Identification of degradation products of indigoids by tandem mass spectrometry
Witkos?, Katarzyna,Lech, Katarzyna,Jarosz, MacIej
, p. 1245 - 1251 (2015)
The study concerns identification of photodegradation products of indigotin, indirubin and isoindigo. Experimental methodology consists of degradation of standard solutions of indigoids in a solar box and analysis of samples taken at different aging time by using capillary high-performance liquid chromatography coupled with electrospray ionization tandem mass spectrometric and spectrophotometric detectors. Identification of the formed compounds was based on careful interpretation of the electrospray ionization MS/MS spectra. Apart from the well-known degradation products of indigoids: isatin, isatoic anhydride and anthranilic acid, another seven species were also identified, and their proposed structures were confirmed by high-resolution molecular masses measurements; according to the best knowledge of authors, they have not been reported so far. The obtained results formed the basis for postulating mechanism of the process. Moreover, the MRM (Multiple Reaction Monitoring) method was developed for the identification of natural dyes and their degradation products in textiles of historical value. Apart from such colorants as indigotin and flavonoids, also presence of degradation products of indigoids was confirmed.
Biotransformation and excretion of nitromethaqualone in rats and humans
Van Boven,Daenens
, p. 1152 - 1157 (2007/10/02)
The metabolic disposition of 14C-labeled nitromethaqualone was investigated in rats. Unlabeled nitromethaqualone was used for studies on humans. Nitromethaqualone was eliminated from the body after most of it had undergone biotransformation. Both humans and rats reduced the nitro group of nitromethaqualone to the corresponding amino derivative, which was partially transformed to the corresponding acetylated form. Cleavage of the quinazolinone nucleus resulting in 2-methoxy-4-nitroaniline was also observed in humans. In rats additional major metabolites arose from the oxidation of the 2-methyl group into hydroxymethyl resulting in 2-hydroxymethyl-3-(2'-methoxy-4'-nitrophenyl)-4(3H)-quinazolinone and concomitant in vivo reduction of the latter resulting in 2-hydroxymethyl-3-(2'-methoxy-4'-aminophenyl)-4(3H)-quinazolinone. Both metabolites were also excreted as glucuronides. In rats fecal excretion accounted for 55-60% of the administered dose, while 24-27% was excreted in the urine. Protracted excretion in both humans and rats indicated an extensive enterohepatic circulation.
