Dear Sir. Concerning your issue about the derivatizing reagent is used for sesquiterpene lactones in HPTLC analysis. TLC was one of the first chromatographic methods and was also applied to analysis of sesquiterpene lactones. Its importance has decreased nowadays. However, in combination with special spray reagents TLC can provide valuable information about the type of sesquiterpene lactone. Visualization reagents are numerous, e.g., vanillin /o-phosphosphoric acid, anisaldehyde or p-dimethylaminobenzaldehyde-sulfuric acid, sulfuric acid, resorcin-sulfuric or phosphoric acid, aluminium chloride or hydroxylamine. sesquiterpene lactones lacking an exocyclic-alpha-methylene group can be visualized by dimethylaminefollowed by Dragendorff reagent. In general, it depends on the skeleton which of the reagents is more favourable. But specifically you can detected it by spray with freshly prepared spray reagent (50 ml of 1% ethanolic solution of ferrous ammonium sulfate were mixed with 5 ml of 1M sulfuric acid,and added to 5 ml ethanolic solution of ammonium thiocyanate), a dark red coloured zone was considered as a positive result. I think the following below link and the attached file may help you in your analysis:
Hi, in addition of the comment from Isam above, I attach a link of CAMAG TLC data base, I think you can search HPTLC methods for your compounds. I inserted the key word sesquiterpene lactone in the data base, I can found 27 publications, best regards
I agree Drs Elgailani & Indrayanto. But I cannot think of a specific 'stain' for a sesquiterpene lactone.. or even for a lactone. Vanillin/ phosphoric acid springs to mind... the colours can help. Sorry