Red yeast rice is produced by cultivating Monascus purpureus on polished rice. China is the world's largest producer of red yeast rice. Red yeast rice may provide benefits beyond those provided by statins. Researchers have reported that the benefits seem to exceed those reported with lovastatin alone [1]. Statins are a class of drugs commonly prescribed to decrease cholesterol levels and have recently been shown to also stimulate bone formation. The HPLC and UPLC methods were developed for the quantitative determination of lovastatin in red yeast rice extracts and dietary supplements that claim to contain red yeast rice. The separation was achieved by using C-18 column material, a water/acetonitrile mobile phase, both containing acid gradient system and a temperature of 35°C. The method was validated for linearity, repeatability, limits of detection (LOD) and limits of quantification (LOQ). The LOD and LOQ of lovastatin were found to be 10 & 50 ng/mL by UPLC-UV method and 100 & 250 ng/mL by HPLC-UV method, respectively. The wavelength used for quantification with the diode array detector was 238 nm. The analysis of commercial products showed considerable variation of 0.37–5.65 µg of lovastatin/g of red yeast extract. LC-mass spectrometry coupled with electrospray ionization (ESI) interface method is described for the identification of lovastatin in red yeast rice samples. This method involved the use of [M+H]+ ions (m/z = 405.2641) in the positive ion mode with extractive ion monitoring (EIM). Acknowledgements: This research is funded in part by “Science Based Authentication of Dietary Supplements” Funded by the Food and Drug Administration grant number 2 U01 FD 002071-07. References: [1] Lu Z, et al. (2008), Am J Cardiol, 101(12): 1689–1693.
Fig. 1 UPLC-UV and HPLC-UV chromatograms of lovastatin, red yeast rice extract and dietary supplements (P-1 to P-3) at 238 nm.
