Neutral, alkaline and difference ultraviolet spectra of secondary metabolites from Penicillium and other fungi, and comparisons to published maxima from gradient high-performance liquid chromatography with diode-array detection.

The ultraviolet spectra of 6 predominantly secondary metabolites from filamentous fungi which, inter alia, are useful in the identification of the compounds after chromatography, were obtained in neutral (methanol) and alkaline solvents. Difference spectra were obtained by subtracting the neutral from the alkaline spectrum for each metabolite, using the spectrophotometer software. The data and method are of use in differentiating metabolites with similar chromophores. A database of the maxima was stored on a microcomputer for flexible storage, retrieval and updating of information. These data are compared to those published previously, obtained by diode-array detection using gradient high-performance liquid chromatography, which indicated that changes in solvent concentrations of the gradient affect the spectra of some metabolites. This could cause misidentification of chemosyndromes and metabolites which have been claimed to be of use in fungal chemotaxonomy.