title: Dual high-resolution inhibition profiling and HPLC-HRMS-SPE-NMR analysis for identification of α-glucosidase and radical scavenging inhibitors in Solanum americanum Mill.
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-2H-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.
authors.affiliation: Instituto de Pesquisas de Produtos Naturais, Centro de Ciências da Saúde, Universidade Federal do Rio de Janeiro, Rio de Janeiro 21941-902, Brazil.
authors.forename: Eder L
authors.initials: EL
authors.lastname: Silva
authors.affiliation: Instituto de Pesquisas de Produtos Naturais, Centro de Ciências da Saúde, Universidade Federal do Rio de Janeiro, Rio de Janeiro 21941-902, Brazil.
authors.forename: Rita C
authors.initials: RC
authors.lastname: Almeida-Lafetá
authors.affiliation: Instituto de Pesquisas de Produtos Naturais, Centro de Ciências da Saúde, Universidade Federal do Rio de Janeiro, Rio de Janeiro 21941-902, Brazil.
authors.forename: Ricardo M
authors.initials: RM
authors.lastname: Borges
authors.affiliation: Department of Drug Design and Pharmacology, Faculty of Healthy and Medicinal Sciences, University of Copenhagen, Universitetsparken 2, DK-2100 Copenhagen, Denmark. Electronic address: ds@sund.ku.dk.
authors.forename: Dan
authors.initials: D
authors.lastname: Staerk
mesh_terms: D002851:Chromatography, High Pressure Liquid; D016166:Free Radical Scavengers / Q000737:chemistry* / Q000302:isolation & purification; D065089:Glycoside Hydrolase Inhibitors / Q000737:chemistry* / Q000302:isolation & purification; D009682:Magnetic Resonance Spectroscopy; D015394:Molecular Structure; D035261:Plant Components, Aerial / Q000737:chemistry; D010936:Plant Extracts / Q000737:chemistry; D010946:Plants, Medicinal / Q000737:chemistry; D032322:Solanum / Q000737:chemistry*; D000520:alpha-Glucosidases / Q000378:metabolism
chemical_list: D016166:Free Radical Scavengers; D065089:Glycoside Hydrolase Inhibitors; D010936:Plant Extracts; D000520:alpha-Glucosidases
keywords: 3-Indolecarboxylic acid (PubChem CID: 69867); 4-Hydroxybenzoic acid (PubChem CID: 135); Antioxidants; Corchorifatty acid B (PubChem CID: 22956671); HPLC-HRMS-SPE-NMR; High-resolution bioactivity profiling; Loliolide (PubChem CID:100332); N-trans-p-Coumaroyloctopamine (PubChem CID: 23874492); N-trans-p-Coumaroyltyramine (PubChem CID: 5372945); N-trans-p-Feruloyloctopamine (PubChem CID: 24096391); N-trans-p-Feruloyltyramine (PubChem CID: 5280537); Rhamnetin 3-O-β-d-galactoside (PubChem CID: 44259577); Solanum americanum; Type 2 diabetes; p-Coumaric acid (PubChem CID: 637542); α-Glucosidase