François Roblot

Two acetogenins from Annona muricata seeds

Abstract Chromatography of a hexane extract of Annona muricata seeds led to the isolation of two new γ-lactone acetogenins, epomuricenins A and B, which are the first examples of annonaceous acetogenins having an epoxide and a double bond in the aliphatic chain in place of the usual tetrahydrofuran moiety. The role of this type of acetogenin in the biogenesis of monotetrahydrofuran acetogenins is discussed.

Isolation and Structure Elucidation of Three New Diglyceride Compounds from Ajuga Iva Leaves

Abstract Three novel compounds were isolated from the leaves of Ajuga iva (Labiatae). Their structures were established, on the basis of spectroscopic data, as symmetric and asymmetric 1,3-diacyl derivatives of glycerol with 3-hydroxy-tetradecanoic and 3-hydroxy-hexadecanoic acids.

An improved method for the formation of formaldehyde acetal derivatives from annonaceous acetogenins

Preparations of 1,2-, 1,3-, 1,5-formaldehyde acetals from the corresponding polyhydroxylated annonaceous acetogenins were performed in good yield. Addition of Et3N to a mixture of DMSO and TMSCl is crucial to avoid in situ hydrolysis of the intramolecular acetals.

Structure elucidation of annoheptocins, two new heptahydroxylated C37 acetogenins by high‐energy collision‐induced dissociation tandem mass spectrometry

Collision-induced dissociation (CID) of lithiated molecules generated by liquid SIMS (LSIMS) from two new natural compounds, annoheptocin A and B, led to their structural elucidation. Mass spectrometry (MS) and tandem mass spectrometry (MS/MS) investigations of their acetonide derivatives displayed obvious differences of reactivity of the lithiated dioxane and dioxolane rings towards CID. The 1,3-dioxane (six-membered) ring could be the target of hydrogen rearrangement processes, leading to the formation of a tetrahydrofuran ring through the loss of a molecule of acetone. Copyright

Essential Oils of Annonaceae. Part VI. Volatile Constituents of the Essential Oils from Five Artabotrys Species

Abstract The essential oils extracted from five Artabotrys species, Annonaceae (A. insignis, A.pierreanus, A. rufus, A. thomsoni and A. venustus) have been examined by GC and GC/MS. The main components of each oil have been identified. Among them, two compounds seem to have a chemotaxonomic significance: cyperenone and 1,5-epoxysalvial-4(l 4)-ene.