Alcaloïdes de Zanthoxylum decaryi: la decarine, nouvel alcaloide dérivé de la benzophénanthridine

Alkaloids from the Stem Bark of Turraeanthus africanus (Meliaceae)

“…This extract was concentrated to dryness under a vacuum. Extensive column chromatography of the residue on silica gel yielded pure 10-O-demethyl-17-O-methyl isoarnottianamide (1) and 11-demethoxyl-12-methoxyl oxynitidine (2), together with two known compounds that were characterized based on their spectral data, and identified as decarine, 4,5) and oxynitidine. Fractionation of the methanol extract of the stem bark of Turraeanthus africanus led to the isolation of two new alkaloids designated turraeanthin A and B, together with two known alkaloids.…”

Synthesis of acrimarins from 1,3,5‐trioxygenated‐9‐acridone derivatives

“…The methylation of 1 with MeI/KOH in DMSO gave compounds 6 and 7 as major products (Scheme 1). The structure of compound 6 was suggested as 1,3,5-t r i m e t h o x y -1 0 -m e t h y l -9 ( 1 0H)-acridinone since the spectral data agreed with that of the previously reported naturally occurring compound [13]. According to the spectral data, the structure of compound 7 was very similar to 6, but it showed an additional methyl group at C-4, as in compound 5.…”

“…Further, the corresponding signals for both acridone and prenylated coumarin residues, indicated in the 13 C nmr spectrum of 10 ( Table 2) provided additional evidence for the proposed structure of 1,3,5-trih y d r o x y -2 -[ 1 " -( 7 ' -m e t h o x y -2 ' -o x o -2H-c h r o m e n -6 ' -y l ) -3 " -methyl-2"-butenyl]-9(10H)-acridinone (10). As in acrimarin 10, the 1 H and 13 C nmr and mass spectral data of acrimarins 11, 12, 13 and 14 also indicated the presence of identical coumarin and prenyl units and their respective acridone moieties. Further, their molecular formulae suggested by MS and confirmed by HRMS were also in agreement with the proposed structures.…”

“…According to the spectral data, the structure of compound 7 was very similar to 6, but it showed an additional methyl group at C-4, as in compound 5. The presence of the additional methyl group was indicated by the sharp singlet at δ 2.31, and the methyl carbon signal at 13.4 in the 1 H and 13 C nmr, respectively. A sharp singlet at δ 6.38 due to the proton at C-2 confirmed the replacement of the C-4 proton by a methyl group.…”

The cyclobuta[b]quinoline alkaloid cyclomegistine from Teclea gerrardii I.Verd. (Toddalioideae: Rutaceae)

“…This compound had previously been reported from two other members of the genus: the Madagascan T. boiviniana (Baill.) H.Perrier (Vaquette et al, 1974), and, more recently, T. trichocarpa Engl. collected in Kenya (Lwande et al, 1983;Muriithi et al, 2002).…”