Christophe Gleye

Apolar Annonaceous Acetogenins from the Fruit Pulp of Annona muricata

A methylene chloride extract of the pulp of Annona muricata L. was fractionated in search for scarcely functionalized Annonaceous acetogenins (type E). Previously known C-35 and C-37 mono-epoxy unsaturated compounds, epomuricenins-A and -B (1+2) and epomusenins-A and -B (3+4), were obtained. Two new mono-epoxy saturated C-35 representatives, epomurinins-A and -B (5+6) were also isolated.

A novel 1-indanone isolated from Uvaria afzelii roots

Bioactivity-guided fractionations of chloromethylenic extract of the roots of U. afzelii (Annonaceae), using Leishmania donovani and Trypanosoma brucei brucei bioassay, resulted in the isolation of the two known compounds, emorydone (1) and demethoxymatteucinol (2), previously isolated from the stems, which were characterised from this source. In addition, the novel 1-indanone, afzeliindanone (3), was also isolated. The structure determination of afzeliindanone (3) was elucidated on the basis of spectral data as 4-[4-hydroxy-3-methoxyphenyl]-indan-1-one. This compound is the first 1-indanone derivative isolated from plants.

ß-Lactamase Inhibitors from Anacardium occidentale

The antimicrobial activity of cashew nut shell liquid (CNSL) and anacardic acids isolated from nuts of Anacardium occidentale were tested against several strains responsible of cutaneous infection or olfactory disagreement. CNSL exhibited minimal inhibitory concentrations (MIC) against Propionibacterium acnes (1.56 µg/mL), Corynebacterium xerosis (6.25 µg/mL), and various strains of Staphylococcus aureus (25 µg/mL), but was not active against the fungus Pityrosporum ovale. The ß-lactamase inhibition was tested by the agar diffusion method with penicillin G, against two strains of S. aureus, both resistant to penicillin by synthesis of ß-lactamase, but one strain being insensitive to all ß-lactamines antibiotics due to a modification of protein linking penicillin (PLP 2a). The results showed clearly the ß-lactamase inhibitory activity of CNSL and anacardic acids on S. aureus enzyme, without activity on PLP 2a.

Semisynthesis of cis- and trans-Solamin by Acidic Opening of Natural Diepomuricanin A − a Mechanistic Investigation

MS/MS spectroscopy allowed us to determine the mechanism of the acidic opening of diepomuricanin A, by analysis of the product distribution after treatment with H218O in the presence of HClO4 in anhydrous acetone.

Muridienin-1 and -2: The missing links in the biogenetic precursors of acetogenins of annonaceae

Isolation of Δn,n+4 diunsaturated γ-lactone derivatives of lacceroic and ghedoic acids, allows us to confirm the biogenetic pathway of the bioactive acetogenins of Annonaceae.