Three new indole alkaloid derivatives from the roots of Murraya paniculata
Three new indole alkaloid derivatives, named paniculidines D?F (1?3), and six known analogs (4?9) were isolated from the roots of Murraya paniculata. The structures were elucidated on the basis of comprehensive HRESIMS, UV, IR, and NMR spectroscopic data
SYNTHESIS OF THE (S)-ENANTIOMER OF PANICULIDINE A. ABSOLUTE CONFIGURATION OF NATURAL PANICULIDINES
The (S)-enantiomer of paniculidine A (an indole alkaloid from the plant Murraya paniculata) was synthesized from (R)-5-acetoxy-4-methylpentanoic acid by its oxidative transformation into (S)-methyl 2-methyl-3-acetoxypropionate, substitution of the acetoxy group by bromine, Wittig reaction of (R)-2-methoxycarbonylpropyltriphenylphosphonium bromide with 1-tosyl-3-formylindole, hydrogenation of the side chain of (Z,S)-3-(3-methoxycarbonyl-1-butenyl)-tosylindole and reductive desulfonylation of (S)-3-(3-methoxycarbonylbutyl)-1-tosylindole.Comparison of the D values of the synthesized (S)-paniculidine A with published data for the natural product showed that the latter has the (R) configuration.Condensation of the (R)-4-(2-tetrahydropyranyloxy)-3-methylbromobutane obtained from (R)-5-acetoxy-4-methylpentanoic acid with β-indolylmagnesium iodide followed by removal of the tetrahydropyranyl protecting group gave the (R)-enantiomer of paniculidinol .Its (S)-enantiomer was prepared by hydride reduction of (S)-paniculidine A.
Cheskis, B. A.,Alekseev, I. G.,Moiseenkov, A. M.
p. 364 - 369
(2007/10/02)
3-PRENYLINDOLES FROM MURRAYA PANICULATA AND THEIR BIOGENETIC SIGNIFICANCE
Three new 3-prenylindoles named paniculidines A, B and C were isolated from the root bark of Murraya paniculata together with the known coumarins murralongin and osthol.Their stuctures were elucidated as methyl 2-(R)-methyl-4-(3-indolyl)-butyrate, 2-(R)-methyl-4-(1-methoxy-3-indolyl)-1-butanol and 2-(R)-methyl-4-(3-indolyl)-1-butanol, respectively, based on the spectroscopic and chemical evidence.The chemotaxonomic and biogenetic aspects of 3-prenylindole in Murraya has been discussed in conjunction with carbazole biogenesis.Key Word Index - Murraya paniculata; Rutaceae; 3-prenylindole; 1-methoxyindole; coumarin; chemotaxonomy; biogenesis.