Sulfonation reactions of (β-carbolines

Abstract

Can. J. Chem. 67,720 (1989).The homogeneous sulfonations of P-carboline derivatives norharmane 2, harmane 3, harmine 4, harm01 5, N,N1-dimethylharmane 6, arid harmaline 7 have been studied in 80-90% w/w sulfuric acid solutions at 25OC. Ultraviolet-visible and I3C nuclear magnetic resonance spectra and chemical analysis of the reaction mixtures show that for all the substrates studied only C-6 sulfonated products are obtained. The sulfonation reactions of the benzene unsubstituted substrates 2 , 3 , and 6 and the partially aromatic substrate 7 proceed by direct electrophilic attack of the H3SO4+ cation on the benzene ring of the P-carboline skeleton. Sulfonation of 4 and 5 at the lower sulfuric acid concentrations is effected by the H3S04+ entity. With increasing sulfuric acid concentration there is a gradual changeover of the sulfonating entity from H3S04+ to H2S207. The different mechanisms of sulfonation are discussed. Can. J. Chem. 67, 720 (1989).OpCrant ?I 25"C, dans des solutions ?I 80-90% P/P d'acide sulfurique, on a ttudit les sulfonations homogknes des derives de la P-carboline que sont le norharmane (2), l'harmane (3), l'harmine (4), l'harmol (S), le N,Nf-dimtthylharmane (6) et l'harmaline (7). Les spectres ultraviolet-visible et rksonance magnCtique nucltaire du I3C et les analyses chimiques des mClanges rtactionnels montrent que tous les substrats CtudiCs ne fournissent que les produits substituis en C-6. Les rCactions de sulfonation des substrats qui ne sont pas substituCs sur le noyau benzinique ( 2 , 3 et 6) ou qui ne sont que partiellement aromatiques (7) se produisent par une attaque Clectrophile directe du cation H3S04+ sur le noyau benzknique du squelette de la P-carboline. La sulfonation des composCs 4 et 5 aux concentrations les plus faibles d'acide sulfurique se produisent sous l'effet de l'entitt H3SO4+ Avec une augmentation de la concentration d'acide sulfurique, il se produit un changement graduel de I'entitC responsable de la sulfonation, de H3S04+ ?I H2S207. On discute des divers mtcanismes de sulfonation.

Cytotoxic Indole Alkaloids against Human Leukemia Cell Lines from the Toxic Plant Peganum harmala

“…Ten known alkaloids were identified as 2-(indol-3-yl)ethyl-β- d -glucopyranoside ( 1 ) [ 16 ], harmol ( 4 ) [ 19 ], harmine ( 5 ) [ 20 ], ruin ( 6 ) [ 21 ], harmic acid methyl ester ( 7 ) [ 22 , 23 ], harmalacidine ( 8 ) [ 24 , 25 ], harmaline ( 9 ) [ 26 ], protonated harmaline ( 10 ) [ 27 ], luotonin C ( 11 ) [ 28 ], and 11-methyoxyl-rutaecarpine ( 12) [ 29 ], by comparison of their spectroscopic data with the corresponding literature.…”