Sennae folium, fructus.......................... Fig

In Sennae folium extract (2) a R, value depression of sennoside A and specifically of sennoside B occur, caused by the mucilages also extracted from the plant material with. 50% methanol. To avoid this effect the circular TLC method can be used (see Fig. 9). Senno,side D (R, — 0,5,5) is more highly concentrated in. Sennae folium extracts (2) tlian in Sennae fructus extracts (1). Senno,side C can be localized at R, — 0.7. Rhein is detectable as a yellow zone at R, 0.8 and its 8-0-glucoside is found between scnno.side D and C. 

B Direct treatment of the TLC plate with the. sodium metaperiodate reagent and heating for 5 min under observation at I00°C reveals green-yellow or dark brownish zones when evaluated under UV-365 nm. It is a fast detection ntefhod, but less sensitive compared with the HNO,/KOFI reagent. 

Circular TLC (CTLC) in comparison to ascending TLC of Senna extracts 

Sennae folium (upper Segment) A sennoside A 0 sennoside D 

Sennae fructus (lower segment) B sennoside B Al aloin 

---