Formation of catharanthine,akuammicine and vindoline in Catharanthus roseus suspension cells

Catharanthine and akuammicine, together with ajmalicine and strictosidine, were isolated from a culture strain of Catharanthus roseus suspension cells. The biosynthetic capability of the cultured cells to produce akuammicine, catharanthine and vindoline was confirmed by feeding experiments with dl-tryptophan-[3-¹⁴C] to yield the radioactive alkaloids.     

Alkaloids of Uncaria attenuata from Thailand

The major alkaloids of a sample of leaves of Uncaria attenuata obtained from Thailand have been identified as the pentacyclic heteroyohimbine alkaloids tetrahydroalstonine, rauniticine and the novel 14-β-hydroxy-3-iso-rauniticine. Evidence for the structure of the new alkaloid was obtained from a study of UV, IR, MS, ¹H NMR and ¹C NMR spectra.     

Alkaloids,limonoids and furocoumarins from three Mexican Esenbeckia species

The chemical constituents of three Mexican Esenbeckia species have been determined. Rutaevin was the main limonoid present in the seeds of all three species, E. litoralis, E. flava and E. berlandieri. The husks, leaves, wood and bark contained a wide array of known furocoumarins and furoquinoline alkaloids. In addition, 1-hydroxy-3-methoxy-N-methylacridone was obtained from E. litoralis bark and a new natural 2-quinolone alkaloid, formulated as 3,3-diisopropyl-N-methyl-2,4-quinoldione, was obtained from E. flava wood. The structure was assigned from spectroscopic considerations and conversion to N-methylhaplofoline.     

Origin of sclerotia-like cells in submerged Claviceps purpurea producing clavine alkaloids

Ultrathin sectioning of submerged mycelium of Claviceps purpurea Tul. producing clavine alkaloids revealed yeast-like budding resulting in asexual sporesblastospores. These deciduous spores were born by extended hyphal cells and retained the same ultrastructure of cell organelles. Both the extended hyphae and the blastospores resembled the cells of ergot sclerotial tissue. A surface culture of C. purpurea Tul. producing no alkaloids was used as a reference.     

La criocerine: Nouvel alcaloide isole des tiges de Crioceras dipladeniiflorus

Seven indolic alkaloids have been isolated from the stem bark of Crioceras dipladeniiflorus. One of them is new and has been called criocerine. Its structure, 7, has been established by use of physical data and chemical correlation with [Δ¹⁴]-vincamine.     

Nicotine N-oxides

Nicotine-1-N-oxide, trans and cis isomers of nicotine-1′-N-oxide and of nicotine-1,1′-di-N-oxide have been prepared and characterised by NMR, MS and reduction to nicotine. The trans and cis isomers of nicotine-1′-N-oxide have been identified in leaves, stems and roots of Nicotiana tabacum, N. affinis and N. sylvestris.     

New organic bases from amazonian Banisteriopsis caapi

Three new bases were isolated from Banisteriopsis caapi; they are harmine N-oxide, harmic acid methyl ester (methyl 7-methoxy-β-carboline 1-carboxylate) and harmalinic acid (7-methoxy-3,4-dihydro-β-carboline 1-carboxylic acid).