Determination of total xanthones in Garcinia mangostana fruit rind extracts by ultraviolet (UV) spectrophotometry

Abstract

Garcinia mangostana (Guttiferae) is an important botanical source of xanthones; these compounds have remarkable pharmacological properties such as anti-cancer, anti-inflammatory and anti-microbial effects. Xanthones-rich extracts have been widely used in nutritional supplements, herbal cosmetics and pharmaceutical preparations. In order to maintain consistency of the pharmacological and clinical outcomes, standardization of crude extracts is crucial for quality control assurance. This study reports development and validation of a ultraviolet-visible (UV-Vis) spectrophotometric method for determination of total xanthones in various G. mangostana fruit rind extracts. The method was validated at 4 wavelengths viz. 243.4, 254, 316.4 and 320 nm. Linearity was in the range of 0.5 to 20 µg/ml; intra-day and inter-day precision, as a relative standard deviation, was 1.1 and 1.8%, respectively; accuracy, limit of detection (LOD) and limit of quantification (LOQ) were in the range of 99 to 104%, 0.101 to 0.124 µg/ml and 0.307 to 0.375 µg/ml, respectively. The highest and lowest xanthones concentration was obtained in toluene extract (99.8%) and methanolic sub-extract (14.6%). The developed method showed high accuracy, sensitivity and selectivity towards xanthones, therefore, it may have an interesting application in routine standardization of G. mangostana extracts and its commercial products. Key words: Garcinia mangostana, total xanthones, ultraviolet-visible (UV-Vis) spectrophotometry.