The Complex Mixture Analysis by NMR (COLMAR; state.edu/index.php/colmar, coordinated by Prof. Rafael Brüschweiler at The Ohio State University) is the most used method for compound identification in mixtures with NMR data. It is well established mainly within the community involved in NMR metabolomics, as this method is accessible via a web server where different analyses can be explored. Importantly, COLMAR has unified metabolite data from two of the most important databases available: BMRB (Biological Magnetic Resonance Data Bank) and HMDB (Human Metabolome Database). Recently, nmrshiftdb2 was included for library matching using CDCl3 for lipids identification. This makes it one of the most comprehensive tools for matching experimental NMR data of complex mixtures to NMR databases. Among the most used features, users can submit their data ( 1 H NMR, C NMR, HSQC and/or TOCSY) for a sequence of library comparisons with data from spectral libraries available in their structure. Thus, users can interactively detect which peaks (and how many peaks) of a particular compound exist in their data and judge their presence within the sample. Although this is a useful tool for analyzing primary metabolites, it may be limited to studies with secondary metabolites. COLMAR relies on high quality experimental spectra acquired using standard conditions and the most commonly used solvent for this database is D2O-phosphate buffer at pH 7.4, although it has been recently complemented by a library of less hydrophilic compounds analyzed in CDCl3. Importantly, matching of experimental data to database are dependent on accurate chemical shift, whereas the chemical shift of 1 H-NMR are very dependent on solvation, solvent pH and temperature. Many compounds of interest in natural products, however, are not soluble in D2O or CDCl3 and their data are also acquired using CD3OD or DMSO.d6, which makes direct comparison with the experimental database problematic.