Quantitative Determination of Cucurbitane-Type Triterpenoids in Dietary Supplements Containing Momordica charantia (Bitter Melon) by LC-MS/MS

Momordica charantia L. (Cucurbitaceae), commonly known as bitter melon, grows in many tropical and subtropical areas of the world and has been used extensively in folk medicines as a remedy for diabetes. In the U.S., many dietary supplements containing bitter melon can be purchased over-the-counter and from internet suppliers. However, no quantitative analytical method has been developed for monitoring the concentration of bitter melon compounds in dietary supplements. The purpose of this study is to investigate the feasibility in using HPLC-MS/MS for the quantitative determination of five cucurbitane-type triterpenoids in dietary supplements containing bitter melon. These compounds were separated on a Synergy Hydro-RP column (150×2.00mm, 4µm) with linear gradient elution of water and acetonitrile, both containing 10 mM ammonium formate and 1% formic acid, and detected by ESI-MS/MS in the positive mode. Quantitative values obtained for each compound using external standard calibration will be compared with standard additions as well as with matrix matched standard calibration to address the matrix effects associated with ESI-MS/MS.