The potent α-glucosidase inhibitor (compound I) was isolated from coffee brews by the activity-based fractionation and identified as a β-carboline alkaloid norharman (9H-pyrido[ 3.4-b]indole) on the basis of mass spectroscopy and nuclear magnetic resonance spectra ((1)H NMR, (13)C NMR, and COSY). The norharman showed a potent inhibition against α-glucosidase enzyme in a concentration dependent ...

Abstract The species-rich genus Palicourea (Rubiaceae: Palicoureeae) is source of an intriguing diversity alkaloids derived from tryptamine and its precursor tryptophan. So far simple analogues, polypyrroloindoline, β-carboline, and, most importantly, monoterpene-indole, i.e., tryptamine-iridoid various structural types including javaniside, alstrostine strictosidine derivatives have been ident...

Eudistomin Y class compounds are a series of β-carbolines which was originally isolated from a marine turnicate or ascidian near the South Korea Sea. These compounds contain bromo-substituted groups, which is one of the typical characters of marine natural products. We report herein the chemical synthesis and biological evaluation of seven new β-carboline-based metabolites, Eudistomins Y1-Y7, a...

Aiming at restricting the conformational freedom of tryptophan-containing peptide ligands, we designed a THBC (tetrahydro-β-carboline)-DKP (diketopiperazine)-based peptidomimetic scaffold capable of arranging in an unusual α-turn conformation. The synthesis is based on a diastereoselective Pictet-Spengler condensation to give the THBC core, followed by an intramolecular lactamization to complet...

The first total synthesis of (+)-7-bromotrypargine, a β-carboline alkaloid from Ancornia sp. is reported. The synthesis proceeds in 9 steps, 8 steps longest linear sequence, in 36.9% overall yield. Biological characterization found that (+)-7-bromotrypargine is an H(3) antagonist, and a selective inhibitor of DAT and NET, without inhibiting SERT. Moreover, unlike electron rich congeners, (+)-7-...

Alkaloid profiles of root and shoot cultures, seedlings and mature plants were analysed by capillary GLC and GLC-MS. beta-Carboline alkaloids, such as harmine, harmaline dominate in normal and root cultures transformed by Agrobacterium rhizogenes, as well as in roots and fruits of the plant. In shoots, flowers and shoot cultures quinoline alkaloids such as peganine, deoxypeganine, vasicinone an...