Alkaloids of Strychnos rubiginosa

A new corynantheine-type alkaloid, strychnorubigine, was identified from root bark of Strychnos rubiginosa D.C. 11-Methoxydiaboline and normacusine B were also isolated and the ¹³C NMR spectral data of their O-acetyl derivatives are reported.     

Protostrychnine,a new alkaloid from Strychnos nux-vomica

The tertiary bases from a sample of Strychnos nux-vomica contain, as well as the expected strychnine and brucine, an unusually high proportion of 4-hydroxy and 4-hydroxy-3-methoxy compounds. The biosynthetic implications of the isolation of a new alkaloid, 12β,13α-dihydro-12α-hydroxyisostrychnine, named protostrychnine, are discussed.     

3-Hydroxydiaboline,a tertiary alkaloid from Strychnos castelnaeana

A new alkaloid, 3-hydroxydiaboline, together with diaboline, was isolated from the upper stem bark of Strychnos castelnaeana. The structure of 3-hy     

Alkaloids of Sri Lankan Strychnos nux-vomica

Twenty-two identified alkaloids have been isolated from the root bark and leaves of a Sri Lankan Strychnos species supplied as S. nux-vomica. T     

Strychnozairine,an indole alkaloid from Strychnos variabilis

Through a combination of spectroscopic techniques (UV, IR, mass spectrometry and NMR) it has been possible to show that strychnozairine, an alkaloid isolated from the root bark of Strychnos variabilis, is N₁-acetyl-16-R-formyl-19-oxo-20,21-didehydrostrychnane.     

Alkaloids and a pimarane diterpenoid from Strychnos vanprukii

From the stem of Strychnos vanprukii, a gluco-indole alkaloid, 3,4-dehydropalicoside, and a pimarane diterpenoid, 7 beta-hydroxypimara-8,15-dien-14-one, were isolated together with four known alkaloids: palicoside, 3,4,5,6-tetradehydropalicoside, akagerine and 17-O-methylakagerine. The structures of these compounds were elucidated based on spectroscopic evidence.     

La 12′-hydroxyisostrychnobiline: Nouvel alcaloïde du Strychnos variabilis

The structure of a new bisindole alkaloid, 12′-hydroxyisostrychnobiline, has been proposed from the analysis of its 300 MHz ¹H NMR spectrum and comparison of the spectroscopic data with those of various monomeric and dimeric alkaloids, previously isolated from the same Strychnos species     

Alkaloids from the leaves of Strychnos wallichiana

The leaves of Strychnos wallichiana Steud. ex. DC. from Bangladesh contain icajine and novacine as their major alkaloids. Smaller amounts of strychnine, brucine, pseudostrychnine, pseudobrucine, N-methyl-sec.-pseudo-β-colubrine, 14-hydroxyicajine, strychnine N-oxide, and brucine N-oxide are also present. The new bases 14 hydroxynovacine and icajine N-oxide have been isolated.     

Alkaloids and iridoids from Strychnos nux-vomica fruits

The alkaloid mixtures present in the fruit pericarp and fruit pulp of Strychnos nux-vomica L. are qualitatively very similar to that found in the seeds. In addition to alkaloids previously known to occur in this plant, small amounts of 4-hydroxystrychnine and the new base N-methyl- sec.-pseudo-β-colubrine have been isolated. Cantleyine, which is a non-indolic base and an artefact, has also been obtained. The iridoid mixture in the fruit pulp is predominantly loganin with small amounts of related compounds, including the biogenetically important secologanin.     

Stryspinolactone,an unusual monoterpene lactone from Strychnos spinosa

The structure of stryspinolactone, an unusual lactone from Strychnos spinosa, was determined from spectroscopic data.     

The structure of isostrychnopentamine,a bisindole monoterpene alkaloid from Strychnos usambarensis

The alkaloid isostrychnopentamine has been shown to be epimeric with strychnopentamine at the asymmetric carbon atom of the N-methylpyrrolidin-2-yl group. Its lUPAC name is 2-[(1′,2′,3′,4′-tetrahydro-2′-methyl-β-carbolin-1′-yl)methyl]-11-(1″-methyl-pyrrolidin-2″-yl)-3-vinyl-1,2,3,4,6,7,12,12b-octahydro-indolo[2,3-a]quinolizin-10-oL [2(S),3(R),12b(S),1′(S),2″(S)].     

Dehydroisostrychnobiline,matopensine and other alkaloids from Strychnos kasengaensis

Eighteen alkaloids have been identified in the root bark, stem bark and leaves of Strychnos kasengaensis from Zaire, They are isoretulinal, retuline, desacetyl isoretuline, desacetyl retuline, dehydroisostrychnobiline, matopensine and its mono-N-oxide, nordihydrotoxiferine, isoretuline, N(1)-desacetyl 18-acetoxyisoretuline, Wieland-Gumlich aldehyde and diol, desacetyl isoretulinal, O-acetyl retuline, 16R-isositsirikine, O-acetyl isoretuline, 11-methoxy retuline and 11-methoxy isoretuline.     

Iridoid glucosides from Strychnos nux-vomica

From seeds of Strychnos nux-vomica three iridoids, 6'-O-acetylloganic acid, 4'-O-acetylloganic acid and 3'-O-acetylloganic acid were isolated together with two known iridoid glucosides, loganic acid and 7-O-acetylloganic acid. The structures of the compounds were established by ESI-MS and by 1D and 2D NMR spectroscopic methods.