Development of a selective HPLC-DAD/ELSD method for the qualitative and quantitative assessment of commercially available Eurycoma longifolia products and plant extracts.
Level 5 - mechanism / opinion, no new human data
Analytical bench chemistry and product surveillance study with no human data (graded by design analogy, not clinical CEBM).
PubMed 29154863 · doi:10.1016/j.fitote.2017.11.015
What was done
An HPLC-DAD/ELSD analytical method was established using 27 reference compounds for qualitative profiling and validated according to ICH guidelines for the quantification of three quassinoids: laurycolactone A, longilactone, and eurycomanone. The method was applied to analyze plant extracts and eight randomly purchased commercial Eurycoma longifolia products.
What was found
Calibration curves were linear from 0.05 to 1.0 mg/ml (R² ≥ 0.9969), with intra-day and inter-day precision <2.9% relative standard deviation and recovery between -3.3% and +6.0%. Only 5 of the 8 tested commercial products contained detectable E. longifolia compounds. In those five, eurycomanone content ranged from 0.22±0.002 mg to 1.84±0.08 mg per capsule, corresponding to a maximal recommended daily intake ranging from 0.76±0.02 mg to 31.90±0.21 mg.
Why it matters
The validated method allows reliable quality control and authentication of commercial Tongkat Ali products, which frequently suffer from adulteration or absence of active quassinoids.
Limits
The market survey evaluated only 8 commercial products. As a purely analytical study, it does not assess clinical efficacy, bioavailability, or human toxicological outcomes.
Cited by
- supports Eurycomanone is the primary active bioactive constituent in Tongkat Ali.