These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


PUBMED FOR HANDHELDS

Search MEDLINE/PubMed


  • Title: Phytochemical identification of Lithocarpus polystachyus extracts by ultra-high-performance liquid chromatography-quadrupole time-of-flight-MS and their protein tyrosine phosphatase 1B and α-glucosidase activities.
    Author: Meng Y, Ding L, Wang Y, Nie QT, Xing YY, Ren Q.
    Journal: Biomed Chromatogr; 2020 Jan; 34(1):e4705. PubMed ID: 31629370.
    Abstract:
    Lithocarpus polystachyus leaves exhibit antidiabetic activity and is consumed as a herbal tea in China. In this study, phytochemical profiles of L. polystachyus leaves were identified and characterized by ultra-high-performance liquid chromatography-quadrupole time-of-flight-MS in both positive and negative ion modes. A total of 17 compounds were tentatively characterized and identified by accurate mass and characteristic fragment ions. The total phenolic contents in the leaf extracts ranged from 9.0 to 13.4 g gallic acid equivalents/100 g of dry weight (DW). In addition, the effect of these extracts on inhibiting the activities of α-glucosidase and protein tyrosine phosphatase 1B (PTP1B) were evaluated. L. polystachyus extracts demonstrated significant inhibition of α-glucosidase (more than 88.1% at a concentration of 1.25 mg/mL) and acarbose (93.6% at a concentration of 5 mg/mL) while the PTP1B inhibition rate was over 84.3%. The antioxidant capacities of the leaf extracts were determined using 2,2-diphenyl-1-picrylhydrazyl, ABTS, and ferric reducing ability of plasma methods and ranged from 50.5 to 72.5 g trolox, from 43.2 to 77.7 g trolox, and from 5.0 to 10.6 g butylated hydroxytoluene (BHT; equaling trolox or BHT per 100 g of DW), respectively. Based on these results, L. polystachyus can be considered as a functional food owing to its antidiabetic and antioxidative activities, which are attributed to its rich phenolic and dihydrochalcone contents.
    [Abstract] [Full Text] [Related] [New Search]