Quantification of Saponins in Asparagus racemosus by HPLC-Q-TOF-MS/MS

Abstract

Asparagus racemosus Willd. or Shatavari (Asparagaceae family) is an important medicinal plant in Ayurvedic medicine as a rejuvenate for women. A method for quantitative analysis of saponin glycosides bioactive constituents in A. racemosus is reported. A high performance liquid chromatography quadrupole time of flight mass spectrometry (HPLC-Q-TOF-MS/MS) method was developed and validated for simultaneous determination of five saponin glycosides, asparacoside, shatavarin IX, shatavarin IV, asparanin A and shatavarin V in A. racemosus extracted with 70% MeOH. The method was validated through intra-and inter-day precision, with the relative standard deviation (RSD) less than 6%, limits of detection (LOD) and limits of quantification (LOQ) <10 and 50 ng, respectively. Overall recoveries ranged from 95% to 105%, with RSD ranging from 0.7% to 4.5%. The method was applied to saponin glycoside contents in the leaves, stems, and roots of A. racemosus sourced from different geographical locations, including four provinces in Thailand, and a sample from India. Saponin glycosides were detected predominantly in the roots, the part used in traditional medicines and these showed wide variations in saponin glycoside profiles from undetectable to 12 mg/g dry weight. The quality control of A. racemosus is crucial for reliable and predictable therapies and only methods like the one developed has the necessary flexibility, sensitivity, accuracy, and selectivity for reliable routine quality control.