Metabolites/intermediates, recording

To record concentrations of metabolites/intermediates during the simulation, click Edit to activate a pop-up dialog box, and use arrow keys to select (transfer)... 

If the objective is identification (qualitative analysis), it suffices to compare the spectrum of the analyte with that of a standard, both recorded in the same solvent and at an identical pH. This is not the main application of UV-Vis spectrophotometry as the best results in this context are provided by spectroscopic methods considered more effective for the study of the molecular structure of organic compounds (infrared, nuclear magnetic resonance, mass spectrometry, and X-ray diffraction). However, UV-Vis spectrophotometry is a source of relevant supplementary information that helps in the elucidation of molecular structures of drugs, impurities, metabolites, intermediate compounds of degradation, etc. 

Figure 6 The structure of the potent quasi-irreversihle CYP3A4 inhibitor troleando-mycin (top panel), the metabolic steps required to convert troleandomycin into a nitroso metabolite that coordinates with the ferrous-heme of CYP3A4 (side panel), and the spectral changes associated with MI complex formation (bottom panel). Troleandomycin (50 pM) was incubated at 37°C with a human liver microsomal sample with high CYP3A4/5 activity (1 mg/mL) andNADPH (1 mM) for the times indicated. The reference cuvette contained the same components minus troleandomycin. Scans from 380 to 520 nm were recorded on a Varian Cary 100 BIO IJV/Vis dual beam spectrophotometer. Abbreviation MI, metabolic intermediate.

---