8-Oxo-erythraline, a naturally-occurring principal alkaloid from Erythrina crista-galli

Structures of New Erythrinan Alkaloids and Nitric Oxide Production Inhibitors from Erythrina crista-galli

“…Phytochemical study of alkaloidal CHCl 3 and n-BuOH extracts of Erythrina crista-galli led to the isolation of two new alkaloids, cristanines A (1) and B (2), together with ten known Erythrinan alkaloids, including erythratine (3), 17) crystamidine (4), 3,11) erysovine (5), erythraline (7), 8-oxoerythraline (8), 18) erythrinine (9), 8-oxo-erythrinine (10), 19) erythratidine (11) and epi-erythratidine (12) 18) as well as one indole alkaloid, hypaphorine (13).…”

“…8,9) The study of biosynthesis of Erythrinan alkaloids in Erythrina crista-galli was reported. [10][11][12] In a previous paper, we described the isolation and characterization of an indole derivative, hypaphorine (13), with a sleep-inducing effect on normal mice 13) and also reported an Erythrinan alkaloid, erysotrine (6), with TRAIL (tumor necrosis factor (TNF)-released apoptosis inducing ligand)-enhancing effect. 14) In this paper, we describe the isolation and structural characterization of new Erythrinan alkaloids, cristanines A (1) and B (2), together with ten known alkaloids (3-5, 7-13) from the bark of Erythrina crista-galli, and these isolated compounds were evaluated for inhibitory activity of lipopolysaccharide (LPS)-induced nitric oxide (NO) production.…”

Synthetic Studies on Heteropolycyclic Natural Products: Development of Divergent Strategy

“…By exploiting reductive transformations, six alkaloids were schematically synthesized and subjected to antiproliferative activity assays, leading to interesting results on the structure-activity relationship. 96) Among the over one hundred erythrina alkaloids that have been identified to date, representative members are 56-63, [97][98][99][100][101][102] which share a central common core structure with A-D rings (Fig. 1).…”

“…Oxidative transformation of the phenol moiety of 78 using singlet oxygen 149) tertiary hydroxy group by thionyl chloride gave 82. Diastereoselective Luche reduction of the enone moiety 150,151) led to 83, which was converted to 8-oxo-erythrinine 101,129) (57) upon methylation and deprotection of the secondary hydroxy group. Subsequent elimination of the hydroxy group under acidic conditions provided crystamidine (56).…”

Caracterização dos alcaloides de Erythrina verna

“…A preesença de dez carbonos sp 2 é característica da subclasse dienoide. Já os sinais com δ 126, 4,127,8,140,7,146,9,147,6 correspondem a carbonos quaternários, uma vez que estes não foram observados no espectro [MANTLE et al, 1984], c 90,6 MHz, [CHAWLA et al,, 1983]. A presença de hidroxila em C-11 é também sugerida pela comparação dos espectros de RMN 13 C da substância 2 e da eritralina (ANEXO C), pois verifica-se que o sinal de C-11 em δ 64,9 no espectro da eritrinina (Tabela 26) está mais desblindado que o sinal deste carbono, situado δ 27,3, no espectro da eritralina (Tabela 24).…”