Abstract
Context: A methanol extract of Cyperus rotundus L. (Cyperaceae) rhizomes showed inhibitory activity against α-glucosidase and α-amylase, two enzymes involve in carbohydrate digestion.
Objective: Identification of compounds from C. rotundus rhizomes responsible for the inhibition of α-glucosidase and α-amylase.
Materials and methods: Compounds were identified by a phytochemical investigation using combined chromatographic and spectroscopic methods. α-glucosidase and α-amylase inhibitory activities were evaluated by in vitro enzyme inhibition assays.
Results: A new (2RS,3SR)-3,4′,5,6,7,8-hexahydroxyflavane (1), together with three known stilbene dimers cassigarol E (2), scirpusin A (3) and B (4) were isolated. Compound 2 inhibited both α-glucosidase and α-amylase activities while the flavane 1 only showed effect on α-amylase, and compounds 3 and 4 were active on α-glucosidase. All four compounds showed significant 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging activity.
Discussion: The inhibitory activities against α-amylase and α-glucosidase of the C. rotundus rhizomes were reported for the first time. Stilbene dimers are considered as potent inhibitors of α-glucosidase and promising antihyperglycemic agents.
Conclusion: The isolated compounds may contribute to the antidiabetic property of C. rotundus.
Acknowledgements
We thank the Institute of Chemistry, Vietnam Academy of Science and Technology, for the NMR and HRMS measurements.