Anxiolytic Effects of Erythrinian Alkaloids from Erythrina mulungu

Abstract

One new erythrinian alkaloid derivative, (+)-11alpha-hydroxyerythravine (1), and the known (+)-erythravine (2) and (+)-alpha-hydroxyerysotrine (3) were isolated from the flowers of Erythrina mulungu. Their structures were determined by spectroscopic/spectrometric data interpretation of 1H, 13C, and 2D NMR and MS experiments. The relative configuration was established by NOESY analysis, while the conformation adopted by these molecules was evaluated through molecular modeling studies and coupling constants obtained by NMR analysis. Furthermore, the anxiolytic effects of the E. mulungu aqueous alcoholic crude extract and of the purified alkaloids were evaluated using the elevated T-maze test.

Tropical biodiversity: has it been a potential source of secondary metabolites useful for medicinal chemistry?

“…The effects of these alkaloids associated with the low toxicity of one standard mixture are currently under study by a Brazilian Pharmaceutical Co. that aims to launch a herbal medicine whose effects could be similar to those produced by diazepam, a classic anxiolytic drug. 84,86 These results suggest that the erythrinian alkaloids isolated from E. mulungu play a major role in the anxiolytic effects of EM and support the popular use of the tincture as an anxiolytic medicine. 85 In Brazil, Senna species are known for several applications, including their ornamental use given their beautiful yellow blossoms.…”

“…Commercial EM preparations are available in Brazil and in the USA as herbal medicine. 84,85 Several Erythrina species have been studied, and studies on E. mulungu conducted by our group have resulted in the isolation of three erythrinian alkaloids, (+)-11α-hydroxyerythravine (60), (+)-erythravine (61), and (+)-α-hydroxyerysotrine (62) ( Figure 15), as well as confirmation of the anxiolytic properties of these erythrinian alkaloids. The effects of these alkaloids associated with the low toxicity of one standard mixture are currently under study by a Brazilian Pharmaceutical Co. that aims to launch a herbal medicine whose effects could be similar to those produced by diazepam, a classic anxiolytic drug.…”

Aplicação de espectrometria de massas com ionização por elétron na análise de alcaloides do mulungu

“…No entanto, não se observa o íon molecular no espectro de massas devido à perda de uma molécula de água na fonte de ionização. O trabalho de Flausino Jr. e colaboradores relatou a presença do alacaloide eritrínico da subclasse dienoide 11-α-hidroxieritravina nas flores de E. verna, 14 o que indica que o carbono 11 é um dos sítios de oxidação. Com base nessa informação e nos dados espectrométricos obtidos, sugere-se que a substância D (Figura 2) possui a estrutura de um alcenoide com oxidação nos carbonos 2 e 11, sendo que no carbono 2 se tem o grupamento carbonila e no carbono 11 há presença de hidroxila.…”

“…12 Seu conhecimento popular provém do fato do uso da decocção das cascas como calmante e indicação para insônia. 13 Estudos recentes realizados pelo Nubbe (IQ-UNESP) e grupos colaboradores [14][15][16] têm dado suporte ao uso popular através da descrição dos efeitos ansiolíticos de vários derivados eritrínicos.…”

Erythrina, a Potential Source of Chemicals from the Neotropics

“…The anxiolytic effects of the E. velutina aqueous alcoholic crude extract and the purified alkaloids of the flowers of this plant were evaluated using the elevated T-maze test, and the light dark transition model ( Flausino, et al, 2007a;Flausino, et al, 2007b). They observed a moderate activity but explain the use of the plant as calm agitation and other disorders of the nervous system.…”