Planta Medica International Open 2017; 4(S 01): S1-S202
DOI: 10.1055/s-0037-1608251
Poster Session
Georg Thieme Verlag KG Stuttgart · New York

High-resolution α-glucosidase inhibition profiling combined with HPLC-HRMS-SPE-NMR for identification of α-glucosidase inhibitors in Machilus litseifolia (Lauraceae)

T Li
1   Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
,
KT Kongstad
1   Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
,
D Staerk
1   Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
› Author Affiliations
Further Information

Publication History

Publication Date:
24 October 2017 (online)

 

Type 2 diabetes is a chronic multifactorial disease affecting millions of people worldwide, and new drug leads with selective α-glucosidase inhibitory activity are urgently needed [1]. In this study, the crude ethyl acetate extract of branches of Machilus litseifolia S.K.Lee showed inhibitory activity of α-glucosidase (IC50= 8.0 ± 1.0 µg/ml), and was therefore investigated using high-resolution α-glucosidase inhibition profiling combined with high-performance liquid chromatography-high-resolution mass spectrometry-solid-phase extraction-nuclear magnetic resonance spectroscopy (HR-bioassay/HPLC-HRMS-SPE-NMR) [2]. Results from the high-resolution inhibition profile of the crude extract were used to guide preparative-scale HPLC towards five fractions correlated with bioactivity (Figure 1). Fraction 1, 4 and 5 were subjected to HR-bioassay/HPLC-HRMS-SPE-NMR using complementary analytical-scale C18 and pentafluorophenyl columns for separation as previously shown by Lima and coworkers [3]. With fraction 1, this led to trapping of 17 compounds correlated with bioactivity, of which the material eluted with peaks 7 and 8 were identified as the new compounds tamarixetin-3-O-α-L-(2'',4''-di-O-cis-coumaroyl)-rhamnopyranoside and tamarixetin-3-O-α-L-(2''-O-cis-coumaroyl-4''-O-trans-coumaroyl)-rhamnopyranoside, respectively. Structural identification of the remaining bioactive constituents from fraction 1, 4 and 5 using HPLC-HRMS-SPE-NMR is in progress.

Zoom Image
Fig. 1

Tuo Li acknowledges the Chinese Scholarship Council for a scholarship. Arife Önder is thanked for technical assistance.

[1] International Diabetes Federation, IDF Diabetes Atlas, 7th ed, 2015

[2] Wubshet SG, Tahtah Y, Heskes AM, Kongstad KT, Pateraki I, Hamberger B, Møller BM, Staerk D. J Nat Prod 2016; 79: 1063 – 1072.

[3] Lima R, Gramsbergen S, Van Staden J, Jäger AK, Kongstad K, Staerk D. J Nat Prod 2017; 80: 1020 – 1027.