J. Pusset

Agelastatin a, a new skeleton cytotoxic alkaloid of the oroidin family. Isolation from the axinellid sponge Agelas dendromorpha of the coral sea

Agelastatin A, isolated from the axinellid sponge Agelas dendromorpha of the Coral Sea, is a new-skeleton alkaloid with, unusually for the oroidin family to which it belongs, marked cytotoxicity toward tumour cells in culture.

Some alkaloids of Alstonia undulata

Abstract Sixteen indole alkaloids have been identified in the root bark and in the leaves of Alstonia undulata from New Caledonia. They are vincamedine, tetrahydroalstonine, alstonidine, deplancheine, fluorocarpamine, pleiocarpamine, 11-methoxyakuammicine, cabucraline, desoxycabufiline, cabucraline- N (4)-oxide, 11-methoxyakuammicine N (4)-oxide, gentiacraline, plumocraline, vincorine, cathafoline and pericyclivine. Five bis indoles of unknown structure have been isolated. The root bark alkaloid mixture contains gentiacraline the first alkaloid made up of an indole and a pyridine alkaloid.

Alkaloids of Alstonia sphaerocapitata

Abstract Twenty alkaloids have been isolated from the leaves, fruit and stem-bark of Alstonia sphaerocapitata from New Caledonia. They were vincamedine, 10-methoxyvincamedine, Z-isositsirikine, akuammicine, quaternoline, 11-methoxyakuammicine, tubotaiwine, 10-methoxyvincamedine N (4)-oxide, cabucraline, cathafoline, caberoline, vincoridine, quebrachidine, quaternoxine, nor C-fluorocurarine, desoxycabufiline, nordesoxycabufiline and three alkaloids of unknown structure.

Alkaloids of Alstonia coriacea

Abstract Seven alkaloids have been identified from the stem bark of Alstonia coriacea from New Caledonia. They are gentianine, 10-methoxy deplancheine, vincamajine, desmethylquaternine, 10-methoxy-3- epi -α-yohimbine, corialstonine and cabucraline. Corialstonine is a novel member of the little represented quinoline alkaloid series.

Alkaloids of Phelline comosa var. Robusta

Abstract Ten alkaloids belonging to the homoerythrinane group have been isolated from the leaves of Phelline comosa var. robusta and identified by spectroscopic methods and chemical correlations.

Alkaloids of melodinus guillauminii

Abstract Fourteen alkaloids were isolated from the stem bark and aerial parts of Melodinus guillauminii . They were 11-hydroxytabersonine, venalstonine, venalstonidine, 14,15-seco-3-oxokopsinal, 3-oxovenalstonine, 11-methoxy-Δ 14 – vincamenine, 3-oxo-hydroxykopsinine, 11-methoxy-Δ 14 -vincanol, kopsinine, 15-α-hydroxykopsinine, 11-methoxy- tabersonine, pleiocarpamine, 19-β-hydroxyvenalstonine and guillauminiine.

Etude de reactions photochimiques XI : Photoxydation de systèmes énolique et diénolique en série stéroïde☆

Abstract The photoxidation of enolic and dienolic systems, of which no example is known in the literature, is described. The enol esters 1 and 2 yield the enones 3 and 4 whereas the dienol ester 5 gives the dienone 6 (35%) through a hydroperoxide E accompanied by 7 (15%) and 8 (10%) which derive from an endo -peroxide F. The last product 9 (10%) has complex origin and its formation can be rationalized by the photoxidation of 5 leading to a 1,2-oxaoxetane G, followed by the autoxidation of a 3,4-diketone 13 originating from the 1,2-oxaoxetane.Abstract The photoxidation of enolic and dienolic systems, of which no example is known in the literature, is described. The enol esters 1 and 2 yield the enones 3 and 4 whereas the dienol ester 5 gives the dienone 6 (35%) through a hydroperoxide E accompanied by 7 (15%) and 8 (10%) which derive from an endo -peroxide F. The last product 9 (10%) has complex origin and its formation can be rationalized by the photoxidation of 5 leading to a 1,2-oxaoxetane G, followed by the autoxidation of a 3,4-diketone 13 originating from the 1,2-oxaoxetane.

Fluorescence spectra and singlet energy of conjugated dienes

Fluorescence spectra of seven cholestadienes have been recorded and their singlet energies have been determined.

Use of tetrabutylammonium cyanide for photocyanation of aromatic compounds: phase transfer photochemistry

Nucleophilic aromatic photosubstitution can be carried out using tetrabutylammonium cyanide in anhydrous acetonitrile or methylene chloride and also under phase-transfer conditions (CH2Cl2–KCN in H2O).

Use of crown ethers for photochemical cyanation of aromatic hydrocarbons

The photocyanation of the aromatic hydrocarbons naphthalene, anthracene, phenanthrene, and biphenyl occurs easily with potassium cyanide dissolved by means of the cyclic polyether 18-crown-6 in anhydrous acetonitrile.