Red yeast rice, a traditional Chinese medicine and food known for centuries to improve blood circulation and maintain taste and color in fish and meat. Preparation of red yeast rice following ancient methods by fermenting the fungal strain Monascus purpureus went on moist and sterile rice. The medicinal properties of red yeast rice were described by pharmacologists of the Ming Dynasty (1368-1644) as cited by Ma et al. [1][2][3][4][5] It is concluded from the present evidence that Red yeast rice possess opportunities for development as new functional foods.6) Red yeast rice, or Hongqu in Chinese, is a typical product in Mingbei area of Fujian province, and a most well known product from Gutiang. 7) From ancient time to now, the method of production all over the countries including Taiwan, and Okinawa (Japan) has been originating from Gutiang and Pinnan counties of Fujian province.7) The modern research has revealed that monacolin K has been proven to be a characteristic constituent of red yeast rice. 8) In this report, monacolin K was identified in red yeast rice of Fujian Province, using high-performance liquid chromatography with photodiode array detector and tandem mass spectrometry. All of these materials including raw material powder and finished products available from the different areas of Fujian province were quantified and the contents of monacolin K were calculated with reference of monacolin K commercially available as the standard.
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ExperimentalChemicals, Reagents and Materials Methanol, HPLC grade; de-ionized water was obtained with an in-house Milli-Q water system (Millipore Inc., U.S.A.). Monacolin K standard was ordered from Sigma (MO, U.S.A.), nine batches of red yeast rice powder were kindly provided by a health food company in Fuzhou, commercial product from the other province of China.Equipment Liquid chromatography and mass spectrometry (LC/ PDA/MS) were carried out using a system equipped with Surveyor LC system (Thermo Finnigan, San Jose, U.S.A.) including quaternary pump, online degasser, column heater compart, autosampler and photodiode array detector, and a LCQ DECA XP MAX mass spectrometer (Thermo Finnigan, San Jose, U.S.A.) that consists of an ESI interface and an ion trap mass analyzer. The software for the control of the equipment, and the acquired and treatment of data is Xcalibur 1.3 workstation.The chemical fingerprints were conducted on the HPLC system of Waters 2695 Alliance (Milford, MA, U.S.A.), consisting of quaternary pump solvent management system, an on-line degasser and an autosampler. The raw data were detected by 2996 photo-diode array detector (PDA), and acquired and processed by Waters Empower chromatographic workstation loaded on a Compaq computer. Prior to each run, the HPLC-PDA system was allowed to warm up for nearly 30 min and the baseline was monitored until stable before the samples were injected.Sample Preparation About 0.3 g red yeast rice powder, accurately weighed, was transferred to a 10-ml tampon centrifuge tube. The preparations were extracted with...
