A Cage-Monoterpene Indole Alkaloid from Alstonia scholaris

Abstract

An unprecedented cage-like alkaloid, scholarisine A was isolated from the leaves of Alstonia scholaris and its structure determined on the basis of 1D and 2D NMR, FTIR, UV, and high-resolution mass spectroscopic data. This alkaloid might be derived from picrinine via oxygenation, rearrangement, and lactonization.

Cymoside, a monoterpene indole alkaloid with a hexacyclic fused skeleton from Chimarrhis cymosa

“…Structural rearrangements of the carbon core of strictosidine-type alkaloid often occur after hydrolysis of the osidic residue, which generates two reactive aldehyde groups. [30][31][32] The high originality in our case is due to an unprecedented double bridge including the establishment of a new C-C bond between the indole and the monoterpene moieties with conservation of the glucose unit.…”

Four new isoflavanones from Tadehagi triquetrum

“…1,2 Previous phytochemical studies found a few of isoflavones and phenols from this species. 3,4 As a part of our continuing research on medicinal plants of DAI ethnopharmacy, [6][7][8][9][10] we investigated the chemical constituents of the whole plants of T. triquetrum, which led to the isolation of four new isoflavanones, named triquetrumones E-H (1-4). Isoflavanones possessing isoprenoid unit, can be considered as the characteristic constituents in this plant.…”

Total Synthesis of (+)-Scholarisine A

“…1 Although no information on the bioactivity of scholarisine A ( 1 ) is currently available, congeners of a putative biosynthetic precursor, picraline ( 3 ), 2 have been reported to be potent, selective inhibitors of SGLT2, a renal cortex membrane protein that regulates glucose re-absorption, that was recently validated as a target for type II diabetes intervention. 3 …”