Triple aldose reductase/α-glucosidase/radical scavenging high-resolution profiling combined with high-performance liquid chromatography–high-resolution mass spectrometry–solid-phase extraction–nuclear magnetic resonance spectroscopy for identification of antidiabetic constituents in crude extract of Radix Scutellariae

• Published in: Journal of Chromatography A Vol. 1408; pp. 125 - 132
• Main Authors: Tahtah, Yousof, Kongstad, Kenneth T., Wubshet, Sileshi G., Nyberg, Nils T., Jønsson, Louise H., Jäger, Anna K., Qinglei, Sun, Staerk, Dan
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 21-08-2015
• Subjects: Aldehyde Reductase - metabolism; Aldose reductase; alpha-Glucosidases - metabolism; Chromatography; Chromatography, High Pressure Liquid; Free Radical Scavengers - analysis; Glycoside Hydrolase Inhibitors - analysis; High-resolution bioactivity profiling; HPLC–HRMS–SPE–NMR; Humans; Hypoglycemic Agents - analysis; Liquids; Magnetic resonance; Magnetic Resonance Spectroscopy - methods; Plant Extracts - analysis; Profiling; Radical scavenging; Radicals; Radix Scutellariae; Recombinant Proteins - metabolism; Reductases; Scavenging; Scutellaria baicalensis - chemistry; Solid Phase Extraction; Spectroscopy; α-Glucosidase; HPLC–HRMS–SPE–NMR; α-Glucosidase; Aldose reductase; Radix Scutellariae; Radical scavenging; High-resolution bioactivity profiling
• ISSN: 0021-9673; 1873-3778
• DOI: 10.1016/j.chroma.2015.07.010

•High-resolution recombinant human aldose reductase assay developed.•High-resolution bioactivity-profiling performed with Radix Scutellariae as proof of concept.•Triple aldose reductase/α-glucosidase/radical scavenging profiles obtained.•High-resolution profiles used for pinpointing antidiabetic constituents.•Structural identification performed with HPLC–HRMS–SPE–NMR.
In this work, development of a new microplate-based high-resolution profiling assay using recombinant human aldose reductase is presented. Used together with high-resolution radical scavenging and high-resolution α-glucosidase assays, it provided the first report of a triple aldose reductase/α-glucosidase/radical scavenging high-resolution inhibition profile – allowing proof of concept with Radix Scutellariae crude extract as a polypharmacological herbal drug. The triple bioactivity high-resolution profiles were used to pinpoint bioactive compounds, and subsequent structure elucidation was performed with hyphenated high-performance liquid chromatography–high-resolution mass spectrometry–solid-phase extraction–nuclear magnetic resonance spectroscopy. The only α-glucosidase inhibitor was baicalein, whereas main aldose reductase inhibitors in the crude extract were baicalein and skullcapflavone II, and main radical scavengers were ganhuangemin, viscidulin III, baicalin, oroxylin A 7-O-glucuronide, wogonoside, baicalein, wogonin, and skullcapflavone II.