Development, Validation, and Application of a Simple and Rugged HPLC Method for Boswellic Acids for a Comparative Study of Their Abundance in Different Species of Boswellia Gum Resins

The resin of Boswellia plant species has been used since ancient times for its several bioactive curative effects. In modern times, extracts of this resin are still widely commercialized on the food supplements and nutraceuticals market. Nowadays the legislation on botanical extracts and the increasing demand for their safety and traceability are setting new standards for their chemical characterization. In this work we present an easy, feasible and rugged HPLC-UV-based approach for the quantitation of boswellic acids in food-supplement-grade resin extracts of Boswellia plant species. This method can be used for quality control purposes as well as for studying their differences in regional origin, years of harvesting and species-related differences. The method employs a C18 (3 x 150 mm, 3 mu m) analytical HPLC column, and the separation is carried out through a gradient of acetonitrile/water with 0.1% formic acid. The method was validated following the ICH guidelines and used to quantitate different samples of commercial resin of Boswellia carteri and serrata together with other samples from unknown species. The six known boswellic acids were identified and quantified in all the analyzed samples. The results were used to build a multivariate model to graphically appreciate their difference through their clustering. The model was then augmented by adding further quantitation data for boswellic acids belonging to different species of Boswellia obtained by another scientific publications to increase the number of studied samples.