Momilactones A and B Are α-Amylase and α-Glucosidase Inhibitors

  • Molecules. 2019 Jan 29;24(3):482. doi: 10.3390/molecules24030482.
Nguyen Van Quan  1 Hoang-Dung Tran  2 Tran Dang Xuan  3 Ateeque Ahmad  4 Tran Dang Dat  5 Tran Dang Khanh  6  7 Rolf Teschke  8
Affiliations
  • 1. Division of Development Technology, Graduate School for International Development and Cooperation (IDEC), Hiroshima University, Higashi Hiroshima 739-8529, Japan. [email protected].
  • 2. Department of Biotechnology, NTT Institute of Hi-Technology, Nguyen Tat Thanh University, 298A-300A Nguyen Tat Thanh Street, Ward 13, District 4, Ho Chi Minh City 72820, Vietnam. [email protected].
  • 3. Division of Development Technology, Graduate School for International Development and Cooperation (IDEC), Hiroshima University, Higashi Hiroshima 739-8529, Japan. [email protected].
  • 4. Central Institute of Medicinal and Aromatic Plants, Process Chemistry and Technology Department, Lucknow 226016, India. [email protected].
  • 5. Khai Xuan International Co., Ltd., 22, 9/53/8 Quan Hoa, Cau Giay District, Hanoi 123000, Vietnam. [email protected].
  • 6. Agricultural Genetics Institute, Pham Van Dong Street, Hanoi 122000, Vietnam. [email protected].
  • 7. Center for Expert, Vietnam National University of Agriculture, Hanoi 131000, Vietnam. [email protected].
  • 8. Department of Internal Medicine II, Division of Gastroenterology and Hepatology, Klinikum Hanau, 63450 Hanau, Germany. [email protected].
Abstract

Momilactones A (MA) and B (MB) are the active phytoalexins and allelochemicals in rice. In this study, MA and MB were purified from rice husk of Oryza sativa cv. Koshihikari by column chromatography, and purification was confirmed by high-performance liquid chromatography, thin-layer chromatography, gas chromatography-mass spectrometry, liquid chromatography-electrospray ionization-mass spectrometry (LC-ESI-MS), and ¹H and 13C nuclear magnetic resonance analyses. By in vitro assays, both MA and MB exerted potent inhibition on α-amylase and α-glucosidase activities. The inhibitory effect of MB on these two key Enzymes was greater than that of MA. Both MA and MB exerted greater α-glucosidase suppression as compared to that of the commercial diabetic inhibitor acarbose. Quantities of MA and MB in rice grain were 2.07 ± 0.01 and 1.06 ± 0.01 µg/dry weight (DW), respectively. This study was the first to confirm the presence of MA and MB in refined rice grain and reported the α-amylase and α-glucosidase inhibitory activity of the two compounds. The improved protocol of LC-ESI-MS in this research was simple and effective to detect and isolate MA and MB in rice organs.

Keywords
anti-diabetes; inhibitory activity; momilactone A; momilactone B; rice by-products; rice grain; α-amylase; α-glucosidase.
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