Novel amide alkaloids from the roots of Piper guineense

Two novel amide alkaloids, wisanine and wisanidine, have been isolated from the petroleum-extract of the roots of Piper guineense, and found to be N-piperidyl-5 (2-methoxy-4,5-methylenedioxyphenyl)-trans-2-trans-4-pentadienamide and N-pyrrolidyl-5-(2-methoxy-4, 5-methylenedioxyphenyl)-trans-2-trans-4-pentadienamide respectively. The structure of wisanidine has been confirmed by synthesis. N-Isobutyl)-trans-2-trans-4-eicosadienamide, recently reported to be present in the fruits of the plant as well as Piperine and Δ^α,β-dihydropiperine have also been found to be major constituents of the roots.     

Glycolone,a quinolone alkaloid from Glycosmis pentaphylla

Glycolone, a quinolone alkaloid has been isolated from the leaves of Glycosmis pentaphylla. The structure of the compound has been established as 4,8-dimethoxy-3-(3-methyl but-2-enyl)-2-quinolone from physical and chemical evidences.     

Locustoside A — A new purine alkaloid glucoside from seeds of Gleditsia japonica

A new purine alkaloid glucoside designated locustoside A has been isolated from the seeds of Gleditsia japonica, which has been used in oriental traditional medicine. The structure was determined as 7-β-d-glucopyranosyl-3-(3-methyl-2-butenyl)-isoguanine by interpretation of spectroscopic data and was confirmed by X-ray crystallographic analysis.     

Sesquiterpenes and alkaloids from Cleistopholis patens

The root bark of Cleistopholis patens collected in Ghana yielded two sesquiterpenes and five alkaloids. The sesquiterpenes have been characterised as the acyclic methyl-(?)-(trans)-(trans)-10,11-dihydroxyfarnesoate and its monocyclic derivative methyl-(+)-10-hydroxy-6,11-cyclofarnes-7(14)-enoate. The alkaloids were of the unusual aza-polycyclic and naphthyridine groups and included one new member of both classes. Examination of stem bark samples from the same source and from Sierre Leone showed the presence of the sesquiterpenes and the oxoaporphine alkaloid liriodenine but neither of the rarer alkaloid types.     

Liriodendronine,an oxoaporphine pigment from discolored sapwood of Liriodendron tulipifera

A new violet oxoaporphine alkaloid. liriodendronine, has been isolated from the discolored sapwood of Liniodendron tulipifera and its structure determined by spectroscopic methods and by conversion into a corunnine-type compound, 2-O,N-dimethylliriodendronine. UV studies demonstrated that the compound exists primarily as a quinone-methide in a neutral medium, a dianion in base, an isoquinolinium ion in weak acid, and as an antiaromatic conjugate acid in conc H₂SO₄.     

Sativanine-C: A cyclopeptide alkaloid from the bark of Zizyphus sativa

From the bark of Zizyphus sativa a previously undescribed 13 membered cyclopeptide alkaloid, sativanine-C has been isolated. The structure of this new compound was elucidated by spectroscopic methods, its transformation product and by chemical degradation.     

Isolation and structure of cucurbitacin Q1

Cucurbitacin Q1, a compound isolated from the fruit of Cucumis prophetarum, has been shown to be the pure trans component of cucurbitacin Q.     

Aculeamine,a solanocapsine-type steroidal alkaloid from Solanum aculeatum

A new solanocapsine-type alkaloid named aculeamine has been isolated from roots of Solanum aculeatum and its structure elucidated by physical methods including X-ray analysis as 22,26-epimino-22β-methoxy- 16α,23-epoxy-5α,22αH,25βH-cholestane-3β-ol. The corresponding 23β-ethoxy compound was also isolated as an artefact.     

Mukonal,a probable biogenetic intermediate of pyranocarbazole alkaloids from murraya koenigii

Mukonal, a carbazole alkaloid has been isolated from Murraya koenigii. The structure of the compound has been established as 2-hydroxy-3-formyl carbazole based on physical (UV, IR, ¹H NMR, ¹³C NMR and mass spectrometry) and chemical transformations.     

(−)-3β-13α-dihydroxylupanine from cytisus scoparius

A new lupin alkaloid, (−)-3β,13α-dihydroxylupanine was isolated from Cytisus scoparius together with five known sparteine-type lupin alkaloids and tyramine. The absolute structure of the new alkaloid was confirmed by comparison of the natural product with the synthetic sample derived from (+)-13-hydroxylupanine. It was also shown that the alkaloid constituents of C. scoparius differed considerably in the aerial parts, flowers and seeds.     

Sulphate ester of trans-4-hydroxypipecolic acid in seeds of Peltophorum

An acidic compound isolated from seed of the legume Peltophorum africanum has been characterised on the basis of FAB-MS, EIMS, ¹³C and ¹H NMR as trans-4-hydroxypipecolic acid-4-sulphate. This is the first naturally occurring sulphate ester of a non-protein amino acid to be described. The possible systematic significance of the distribution of the ester within Peltophorum and related genera is considered.     

(−)-N-ethylcytisine,a lupin alkaloid from the flowers of Echinosophora koreensis

A new lupin alkaloid, (?)-N-ethylcytisine, was isolated from the fresh flowers of Echinosophora koreensis. Its structure has been confirmed b     

Antifungal Compound,Feruloylagmatine, Induced in Winter Wheat Exposed to a Low Temperature

An antifungal compound, feruloylagmatine [1-(trans-4′-hydroxy-3′-methoxycinnamoylamino)-4-guanidinobutane], was isolated from crowns of winter wheat (Triticum aestivum L. cv Chihokukomugi). Its structure was identified by NMR, MS and UV spectral analyses. It was also confirmed by an HPLC analysis that the compound was induced in wheat by a low temperature.     

Glycozolidol,an antibacterial carbazole alkaloid from Glycosmis pentaphylla

Glycozolidol, a new carbazole alkaloid, has been isolated from the roots of Glycosmis pentaphylla. Its structure has been established as 6-hydroxy-2-methoxy-3-methylcarbazole on the basis of physical and chemical evidence. The compound has been found to be active at some Gram-positive and Gram-negative bacteria.     

Directed biosynthesis of unnatural alkaloids in Dolichothele sphaerica

Using appropriate precursors, the two unnatural alkaloids 4(5)-[N-isocaproylaminomethyl]imidazole and 3-[2-N-isovalerylaminoethyl]pyrazole were produced by Dolichothele sphaerica. The former compound represents an unnatural alkaloid formed by the simultaneous introduction of two unnatural precursors, namely isocaproic acid and 4(5)-aminomethylimidazole. The latter compound represents an aberrant alkaloid formed by the introduction of a precursor of different heterocyclic entity, 3-aminoethylpyrazole.     

Nouveaux acides amines libres de Afzelia bella: trans-hydroxy-4-L-proline et trans-carboxy-4-L-proline

Two new free amino acids have been isolated from seeds of Afzelia bella: trans-4-hydroxy-L-proline and trans-4-carboxy-L-proline. They are accompanied by relatively large quantities of proline, pipecolic, acid, 4-methylene-DL-proline, cis-4-hydroxymethyl-L-proline and 4-methylene-L-glutamic acid. Small amounts of acetylornithine are also present. It is the first time that trans-4-hydroxy-L-proline has been found as a component of the free amino pool of plants.     

Ravesilone,a quinolone alkaloid from Ravenia spectabilis

A new quinolone alkaloid designated ravesilone has been isolated from the leaves of Ravenia spectabilis. From spectral evidence the structure of the compound has been established as 3,4,5,6-tetrahydro-7-hydroxy-2,2,6-trimethyl-5-oxo-2H-pyrano[3,2-c]quinoline.     

Identification of Traumatin, a Wound Hormone, as 12-Oxo-trans-10-dodecenoic Acid

12-Oxo-trans-10-dodecenoic acid (trans-10-ODA) is an oxidation product of polyunsaturated fatty acids in plant tissues. The structural similarity of trans-10-ODA and traumatic acid, a compound considered to be a wound hormone, suggested that trans-10-ODA might be a precursor of traumatic acid. Both trans-10-ODA and traumatic acid were active in the Wehnelt bean assay. The results were more consistent with trans-10-ODA than with traumatic acid. Cucumber (Cucumis sativus L. var. National Pickling) hypocotyls also showed a growth increase following treatment with trans-10-ODA, which suggested that trans-10-ODA has a more general influence on plant development than previously ascribed to traumatic acid.     

Koenoline,a further cytotoxic carbazole alkaloid from Murraya koenigii

Koenoline, a carbazole alkaloid, has been isolated from the root bark of Murraya koenigii for the first time as a natural product. Its structure was established as 1-methoxy-3-hydroxymethylcarbazole by analysis of spectroscopic data and was confirmed by partial synthesis from murrayanine isolated from M. siamensis roots. Koenoline exhibited cytotoxic activity against the KB cell-culture test system.     

Pachyovatamine,a bisbenzylisoquinoline alkaloid,and other alkaloids from Pachygone ovata

A new dibenzo-p-dioxin biphenyl bisbenzylisoquinoline alkaloid, pachyovatamine, has been isolated from an extract of the leaves and stems of Pachygone ovata from Sri Lanka. The alkaloid was characterized by a consideration of its physicochemical data and conversion to O-acetyltiliacorinine. Pachygonamine, N-methylpachygonamine and tiliamosine were also isolated from the same extract.