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Structural Elucidation and Complete NMR Spectral Assignments of Monascus Monacolin Analogs
Jiachen Liu1, Qingjiang Xu1, Xin Wang1
1College of Applied Arts and Science, Beijing Union University, Beijing, China.
Magnetic Resonance in Chemistry : MRC
|November 5, 2024
Summary
Researchers isolated three new monacolin compounds from red yeast rice. This study provides the first complete NMR data assignments for two of these novel natural products.
Area of Science:
- Natural Product Chemistry
- Organic Chemistry
- Biochemistry
Background:
- Red yeast rice is a fermented product with a long history of use in traditional medicine.
- It is known to contain various bioactive compounds, including monacolins, which are structurally related to statins.
- Further investigation into the chemical constituents of red yeast rice can lead to the discovery of novel compounds with potential health benefits.
Purpose of the Study:
- To isolate and characterize new monacolin analogs and monacolin-like natural products from red yeast rice.
- To elucidate the structures of these isolated compounds using advanced spectroscopic techniques.
- To provide complete Nuclear Magnetic Resonance (NMR) data assignments for the newly identified compounds.
Main Methods:
- Extraction of bioactive compounds from the ethyl acetate portion of red yeast rice ethanol extract.
- Structure elucidation using High-Resolution Electrospray Ionization Mass Spectrometry (HRESIMS).
- Comprehensive NMR experiments, including Heteronuclear Single Quantum Coherence (HSQC), Heteronuclear Multiple Bond Correlation (HMBC), Proton-Proton Correlation Spectroscopy (¹H-¹H COSY), and Nuclear Overhauser Effect Spectroscopy (NOESY) for complete data assignments.
Main Results:
- Isolation and identification of one new monacolin analog, monacolin V (1).
- Isolation and identification of two new monacolin-like natural products, 6-hydroxyl monacolin P (2) and 3-keto monacolin S (3).
- Complete assignments of ¹H and ¹³C NMR data were achieved for all three isolated compounds, with compounds 2 and 3 being reported for the first time.
Conclusions:
- The study successfully identified three novel monacolin-related compounds from red yeast rice.
- The comprehensive NMR data provided advances the characterization of these natural products.
- This research contributes to the understanding of the chemical diversity of red yeast rice and provides valuable data for future studies.
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