Determination of Cassiarin A Level of Cassia siamea Leaf Obtained from Various Regions in Indonesia Using the TLC-Densitometry Method.

Cassia siamea leaf has been proven in vitro and in vivo to have a strong antimalarial activity with Cassiarin A as its active compound. To obtain a source of C. siamea medicinal plant with high level of active antimalarial compound (Cassiarin A), a valid method for determining Cassiarin A level is needed. For this reason, this research conducts the validation of the Cassiarin A content with determination method using thin-layer chromatography (TLC) densitometry which includes the determination of selectivity (Rs), linearity (r), accuracy, precision, limit of detection (LOD), and limit of quantification (LOQ). Cassiarin A was chromatographed on silica gel 60 F254 TLC plate using chloroform : ethanol (85 : 15 v/v) as a mobile phase. Cassiarin A was quantified by densitometric analysis at 368 nm. The linear regression analysis data for the calibration plots showed good linear relationship with r = 0.9995. The method was validated for precision, recovery, repeatability. The minimum detectable amount was found to be 0.0027 μg/spot, whereas the limit of quantitation was found to be 0.008 μg/spot. The results of this validation are then used to determine the Cassiarin A level of C. siamea leaf from various regions in Indonesia. Based on the results of the study, it can be concluded that the TLC-densitometry method can be used to determine level of the Cassiarin A compound with the advantages of being fast, easy, accurate, and inexpensive. In addition, it showed that C. siamea leaves from Pacitan have the highest level of Cassiarin A compared to other areas studied.