Analysis of crude extracts and fractions of brazilian polypodiaceae by high-resolution gas chromatography-mass spectrometry. I. triterpenes

Characterization of individual components in plant extracts through classical phytochemical methods is a multi‐step procedure which is both costly and time‐consuming. Also significant amounts of extract are required and detection of minor compounds is frequently not possible. The method described in this work involves direct analysis of crude or prefractioned apolar or medium‐polar extracts by high‐resolution gas chromatography and computerized high resolution gas chromatography‐mass spectrometry, followed by co‐injections of the crude extract with certified standards on capillary columns of different polarities. The effectiveness of the method is illustrated for several species of Polypodiaceae (spores and rhizomes). allowing easy monitoring of compound‐type distributions (e.g. triterpenes) and detection of structures present at trace levels (for example, 22,29,30‐trisnorhopane).