Development and Validation of Novel Quality Evaluation Methods to Differentiate Two Closely Related Species of Tinospora: A Rapid HPTLC- and HPLC-Based Assessment with MS/MS Characterization.

Abstract

The sympatric occurrence of the species that often resulted in different gatherings of plant material, ambiguous history on traditional use, and taxonomic flux due to similarities within the Tinospora (Menispermaceae) taxa are some of the reasons that triggered the necessity to develop robust analytical methods for efficient QC, especially to recognize dry and powder forms. To develop novel HPTLC-based fingerprinting of two closely resembling Tinospora species followed by HPTLC-MS analysis and identification of compounds differentiating Tinospora crispa (TCP) and Tinospora cordifolia (TCR) and a rapid and quantitative assessment by HPLC with a photodiode array detector (HPLC-PDA) with MS/MS characterization of specific TCP and TCR analytical markers. An HPTLC-based method was developed using chloroform-toluene-methanol-formic acid (7 + 4 + 2 + 0.2, by volume). The TCP compounds could be distinguished and isolated using successive column chromatography with complete characterization. Further these used in the reverse phase (RP)-HPLC-PDA coupled with LC-ESI (electrospray ionization)-MS/MS to quantify and confirmation in TCP and TCR. The fingerprinting showed distinct bands in TCP stems, confirmed as clerodane- furanoditerpenoids with indirect profiling by the HPTLC-MS technique. Systematic isolation confirmed these compounds as borapetosides B and E. Thus, the RP-HPLC-PDA method was developed for these borapetosides B and E, with tinosporide to differentiate these two species. The quantitation method was well validated with good linearity (r2 >0.99) with sensitive LOD (0.49-3.71 mcg/mL) and LOQ (1.48-11.23 mcg/mL) with recoveries of 92.34-96.19%. A novel, validated HPLC-PDA method showed good resolution and reliability (up to 1% adulteration) in quantification for targeted major analytical markers from TCP to differentiate TCR. Thus, HPTLC and HPLC-PDA-based techniques are helpful with MS/MS-based characterization to identify and quantify these analytical markers from TCP (borapetoside B and E) and TCR (tinosporide) in dry and powder form. This article reports on the systemic use of HPTLC-MS for separating and identifying analytical markers in Tinospora species, distinguishing TCR and TCP with quantitative HPLC-PDA and MS/MS assessment.