Development of a chemical fingerprint as a tool to distinguish closely related Tinospora species and quantitation of marker compounds.

Tinospora species are morphologically similar. Several cases of human toxicity have been reported in association with T. crispa. A chemical fingerprint was developed to differentiate T. crispa from its closely related species and to quantitate its major furanoditerpenes namely as borapetosides B, C and F. The rapid, sensitive and repeatable method was established using ultra-high performance liquid chromatography coupled with photodiode array and single quadrupole electrospray mass spectrometry detectors using a flavonoid, two alkaloids, an amide and six diterpenoids. Qualitative and quantitative determination was performed by UHPLC-UV and confirmed by MS. The intra-day RSD for replicates was between 0.9 and 6.8% and inter-day RSD was between 1.2 and 9.1%. Recovery was 97-103 %. The method is useful to achieve decisiveness in not only identifying but also differentiating T. crispa from T. sinensis and other closely related Tinospora species. Seventeen Tinospora plant samples and seventeen dietary supplements claiming T. crispa, T. sinensis and T. cordifolia were analyzed. The newly developed and validated method successfully resulted in the conclusive identification of two dietary supplements to be mislabeled.