Petasitidis folium

Powdered drug (2g) is extracted by heating under reflux for about 20 min with about Farfarae folium, 40ml light petroleum on a water bath. The clear filtrate is concentrated to about 1 ml, Petasitidis folium and 30 pi is used for chromatography. (test for petasins)... 

Fig. I2C Methanoltc extracts of Farfarae folium (4) and the adulterant Petasitidis folium (5-7) have a very similar pattern of blue fluorescent phenol carboxylic acids. Flavonoid monoglycosides (R, range 0.5-0.65) are present in varying concentrations in Petasites species, while rutin is not detectable in the samples 5,6 and there are only traces in sample 7.

D For the detection of the sesquiterpenes e.g. petasol, neo- and isopetasol derivatives, a petrol ether extract has to be prepared. TLC development in CHClj and deteaion with concentrated ILSO., (98%) reveals the lipophilic compounds of Farfarae (4) and Petasitidis folium (5-7) as white-blue, red or green-blue zones over the whole R, range. The sesquiterpene petasiil/isopetasin are found in the R, range 0.4-0.45 as green-blue fluorescent zones. The concentration of the esters (e.g. methacryl petasol) varies, depending on the Petasites species. 

Petasites sample (7). shows the petasin/isopetasin as prominent zones, while in Petasitidis folium samples 5 and 6 the petasin is present in low concentration. Petasin-free chemical races also exist. In these cases Patasitidis and Farfarae folium extracts are hardly distinguishable. The red zones are due to furanoeremophilanes. 

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