New Antidiabetic and Free-Radical Scavenging Potential of Strictosamide in Sarcocephalus pobeguinii Ground Bark Extract via Effect-Directed Analysis

Abstract

The active principle of most traditional medicines is not known, as for Sarcocephalus pobeguinii Hua ex Pellegr. bark extract. It is used as an antidiabetic drug in Gabonese folk medicine. Diabetes mellitus is increasing globally, and products from natural sources are gaining interest as a remedy. As the active antidiabetic compounds have not been characterized so far, a mobile phase for high-performance thin-layer chromatography (HPTLC) was newly developed to target single active compounds in the unpolar ground bark extract of S. pobeguinii by effect-directed analysis (EDA). One natural compound zone showed multipotent activities by effect-directed detection, that is, antidiabetic, cholinesterase inhibiting, and antioxidative activities. Its characterization was performed via online elution of the active substance zone from the HPTLC layer into the high-resolution mass spectrometry (HRMS) system. Important parts of the structure were assigned by MS/MS experiments and led to the preliminary assignment of strictosamide, an indole alkaloid. The saccharide moiety of the active molecule was characterized with a selective derivatization reagent (diphenylamine aniline phosphoric acid reagent). Strictosamide was already reported as a constituent of the extract, and its cholinesterase inhibiting property was confirmed. However, it was newly found to be active as a free-radical scavenger and α-glucosidase inhibitor, which might partially explain the successful use as antidiabetic and antioxidative folk medicine. The fast bioprofiling by HPTLC-UV/vis/FLD-EDA-HRMS was proven to be suited as an analytical tool for the discovery of multipotent active compounds.

Total Syntheses of (−)‐Strictosidine and Related Indole Alkaloid Glycosides

“…Strictosamide ( 3 ) has been isolated from several species, such as Nauclea , Palicourea , Ophiorrhiza , Psychotria , Triosteum , Strychnos , Vinca , and Sarcocephalus species . In addition, several useful biological activities have been reported, including antiplasmodial, antiviral, antiproliferative, anticarcinogenic, acetyl‐/butyrylcholinesterase inhibitory, antiinflammatory, antidiabetic, and antioxidative activities …”

Total Synthesis of (−)-Strictosidine and Interception of Aryne Natural Product Derivatives “Strictosidyne” and “Strictosamidyne”

“…The C3 epimer was also observed (16% yield, not depicted) . We also took advantage of the opportunity to make new derivatives of strictosamide, a related natural product. − As such, a single diastereomer of 19 (as depicted) was treated with sodium carbonate to afford 20 , which we envisioned serving as a precursor to the aryne derivative of strictosamide we term “strictosamidyne”.…”

New planar assay for streamlined detection and quantification of β-glucuronidase inhibitors applied to botanical extracts

“…5 C), indicating a molecular formula of C 21 H 20 O 8 (calculated m/z 435.08522 for [M+Cl] ─ ). In HPTLC-MS, a chlorine adduct can be caused by the surrounding atmosphere or from residual chlorinated solvent traces in the instrumental system (from prior users) [ [45] , [46] ]. For confirmation of the molecular formula, the measurement was performed in the positive ion mode ( Fig.…”