1. Dual high-resolution inhibition profiling and HPLC-HRMS-SPE-NMR analysis for identification of α-glucosidase and radical scavenging inhibitors in Solanum americanum Mill.
- Author
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Silva, Eder L., Almeida-Lafetá, Rita C., Borges, Ricardo M., and Staerk, Dan
- Abstract
Solanum americanum is one of the most prominent species used to treat type 2 diabetes in Guatemala. In our ongoing efforts to find antidiabetic and antioxidative compounds from natural sources, an ethyl acetate extract of this medicinal herb was investigated using dual high-resolution α-glucosidase/radical scavenging inhibition profiling. The high-resolution biochromatograms obtained by this technique were used to target subsequent structural elucidation by HPLC-HRMS-SPE-NMR analysis towards the bioactive constituents. This led to identification of 4-hydroxybenzoic acid ( 1 ) and 3-indolecarboxylic acid ( 6 ) associated with radical scavenging activity, and the amide alkaloids N - trans - p -coumaroyloctopamine ( 3 ), N - trans - p -feruloyloctopamine ( 4 ), N - trans - p -coumaroyltyramine ( 8 ) and N - trans - p -feruloyltyramine ( 9 ) correlated with α-glucosidase inhibitory activity as well as radical scavenging activity. Further analysis revealed a new lactone, methyl 5-ethyl-4-hydroxy-5-methyl-2-oxotetrahydro-2 H -pyran-4-carboxylate ( 7 ) and a new steroid with a rare F ring ( 11 ). Corchorifatty acid B ( 12 ) was reported for the first time in the Solanaceae family. Their structures were elucidated by extensive use of 1D and 2D NMR spectroscopy as well as HRMS analysis. [ABSTRACT FROM AUTHOR]
- Published
- 2017
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