Diego Cortes

Inhibition of calcium entry induced by cularines and isocrasifoline in uterine smooth muscle

The effects of nifedipine, papaverine and four benzylisoquinoline alkaloids (cularine, cularidine, celtisine and isocrasifoline) were studied in isolated rat uterus in order to clarify the mechanism of their relaxant action. All the compounds tested completely relaxed KCl-induced contractions and totally or partially inhibited oxytocin-induced rhythmic contractions. Only papaverine acted intracellularly, promoting relaxation of contractile responses induced by oxytocin or vanadate in a Ca(2+)-free medium. In spite of the structural relationship between papaverine and the other alkaloids, the mechanism of their relaxant action is not the same. The activities of cularine derivatives and of isocrasifoline were similar to that of nifedipine.

Bioactive acetogenins from seeds of Annona cherimolia

Abstract Two new cytotoxic, nonadjacent bis-tetrahydrofuran acetogenins, cherimolin-2 and almunequin, have been isolated from the bioactive methanolic extract o

Molvizarin and motrilin : two novel cytotoxic bis-tetrahydro-furanic γ-lactone acetogenins from Annona cherimolia

Abstract Two new cytotoxic adjacent bis-tetrahydrofuranic acetogenins, molvizarin and motrilin, have been isolated from the cytotoxic methanolic extract of Annona cherimolia seeds. Their structures were established on the basis of 2D-NMR spectroscopic techniques. While molvizarin ( 1 ) belongs to the very rare type of C 35 bis-tetrahydrofuranic acetogenins, motrilin ( 2 ) is the first example of a C-29 hydroxylated acetogenin.

A new type of cytotoxic acetogenins: the tetrahydrofuranic β-hydroxy methyl γ-lactones

Abstract A new type of cytotoxic Annonaceous acetogenins has been isolated from Annona cherimolia seeds. The structures of two new acetogenins, itrabin ( 1 ) and jetein ( 2 ), characterized by a saturated β-hydroxy methyl γ-lactone moiety with one or two tetrahydrofuran rings, were established on the basis of 2D NMR experiments.

Corepoxylone, a possible precursor of mono-tetrahydrofuran γ-lactone acetogenins: biomimetic synthesis of corossolone☆

Abstract A new diepoxy acetogenin with a carbonyl group, corepoxylone ( 1 ), has been isolated from the non-polar fractions of Annona muricata seeds. Its structure was elucidated on the basis of the spectral data, NMR and MS in particular. Biomimetic synthesis of corossolone ( 2 ) from ( 1 ) suggests its role in the biogenesis of mono-tetrahydrofuran acetogenins bearing a carbonyl group at C-10.

Formation of gas-phase lithium complexes from acetogenins and their analysis by fast atom bombardment mass spectrometry☆

Abstract The Annonaceous acetogenins form complexes with lithium in a liquid matrix. Fast atom bombardment (FAB) combined with linked scan (B/E and B2(1 -E)/E2) mass spectrometry of a lithium cationized acetogenin, rolliniastatin-2, was used to analyze the metastable dissociations of the complex, leading to structurally useful information.

Catalytic hydrogenation of annonaceous acetogenins

Abstract Catalytic hydrogenation of cytotoxic Annonaceous acetogenins afforded two or one diastereomers whether the γ-unsaturated lactone acetogenin possesses or not an hydroxyl group at the 4-position.

Alkaloids from Sarcocapnos saetabensis

Abstract Twenty-one isoquinoline alkaloids were isolated from Sarcocapnos saetabensis . Eighteen of them were identified as the known alkaloids (+)-celtine, (+)-chelamine, (+)-chelidonine, (+)-crassifoline, (+)-cularine, dehydroglaucine, (+)-glaucine, (+)-4-hydroxysarcocapnidine, (+)-isocorydine, O -methylatheroline, (−)- O -methylpallidine, oxocularine, oxosarcocapnidine, pontevedrine, protopine, (+)-salutaridine, (+)-sarcocapnidine and (−)-scoulerine. The remaining three were the new alkaloids (+)-14-epichelidonine, isonoyaine and (−)- N -methylviguine, whose structures were established by spectroscopic and chemical methods.