High Performance Thin layer Chromatography: Densitometry Method for Determination of Rubraxanthone in the Stem Bark Extract of Garcinia cowa Roxb

Context: Garcinia cowa is a medicinal plant widely grown in Southeast Asia and tropical countries. Various parts of this plant have been used in traditional folk medicine. The bark, latex, and root have been used as an antipyretic agent, while fruit and leaves have been used as an expectorant, for indigestion and improvement of blood circulation. Aims: This study aims to determine the concentration of rubraxanthone found in ethyl acetate extract of the stem bark of G. cowa by the high‑performance thin‑layer chromatography (HPTLC). Materials and Methods: HPTLC method was performed on precoated silica gel G 60 F254 plates using an HPTLC system with a developed mobile‑phase system of chloroform: ethyl acetate: methanol: formic acid (86:6:3:5). A volume of 5 μL of standard and sample solutions was applied to the chromatographic plates. The plates were developed in saturated mode of twin trough chamber at room temperature. The method was validated based on linearity, accuracy, precision, limit of detection (LOD), limit of quantification (LOQ), and specificity. The spots were observed at ultraviolet 243 nm. Results: The linearity of rubraxanthone was obtained between 52.5 and 157.5 ppm/spot. The LOD and LOQ were found to be 4.03 and 13.42 ppm/spot, respectively. Conclusion: The proposed method showed good linearity, precision, accuracy, and high sensitivity. Therefore, it may be applied for the quantification of rubraxanthone in ethyl acetate extract of the stem bark of G. cowa.