DEVELOPMENT AND VALIDATION OF A HPLC METHOD FOR DETERMINATION AND QUANTIFICATION OF RUBRAXANTHONE IN STEM BARK EXTRACT OF MANGOSTEEN

Rubraxanthone is one of antibacterial and antioxidant compound which is isolated from stem bark of mangosteen ( Garcinia mangostana Linn.). The precise method for analysis of plant constituents is normally a reverse-phase high performance liquid chromatographic (RP-HPLC). Development and validation of a RP-HPLC method for chromatographic separation was carried out on a reversed-phase column Shimadzu ® Shimp-pack VP – ODS (4.6x250mm) using an isocratic mobile phase of 0.4% formic acid - acetonitrile at a flow rate 1mL min -1 , and detection was with a UV detector. The linearity of the proposed method was found in the range of 2.5-25μg/mL -1 with regression coefficient 0.999. Intraday precision studies showed the relative standard deviation ≤1.58% and inter-day ≤3.20%. Accuracy of the method was determined by a recovery study conducted at 3 different levels, and the average recovery was 102.18%. The Limit of Detection Limit of Quantitation (LOQ) and were 0.47 and 1.56μg/mL -1 .The contents of rubraxanthon in the crude was 0.23±0.07%w/w.