ABSTRACT:

Context: The cat's whiskers (Orthosiphon aristatus (Blume) Miq) plant has been widely used for traditional medicine both in preventive measures and companion therapy. The color of the O. aristatus flower is divided into purple, white-purple, and white varieties. To ensure the quality of the O. aristatus it is necessary to make standardization efforts. Specific standardization parameters are the identification and determination of marker compound levels. Sinensetin is a marker compound in O. aristatus. The research aimed to analyze qualitatively and quantitatively the content of sinensetin in the acetone extract of the purple and white-purple varieties of O. aristatus Extraction was carried out using maceration, which began with determining the ratio of the number of leaves and stem simplicia of two varieties of O. aristatus and acetone solvent. Sinensetin compound identification was carried out on acetone extract and subfraction. Determination of the levels of sinensetin in acetone extract was carried out by thin-layer densitometry chromatography (TLC-Densitometry). Based on the optimization results using TLC, the weight ratio of the simplicia and the amount of solvent is 1 g of simplicia in 15 mL of solvent. Sinensetin compounds were detected in the leaves' acetone extract and stem of two varieties of O. aristatus. The highest sinensetin content was in the acetone extract of purple variety leaves with levels of 0.51% w/w. The acetone extract of the purple variety leaves was further separated by vacuum liquid chromatography and preparative thin-layer chromatography. The results showed a sinensetin compound in the acetone sub-fraction. This study's results can be the basis for the specific characterization of O. aristatus especially those grown in Indonesia, to ensure product quality consistency from traditional medicinal plants.

Keywords: O. aristatus, purple and white-purple varieties, standardization, sinensetin, qualitative and quantitative analysis.