Jean Wandji

Prenylated isoflavonoids from Erythrina sensegalensis

Abstract Two novel prenylated isoflavonoids, 3,5,4′-trihydroxy-8-(γ,γ-dimethylallyl)-2″, 2″-dimethylpyrano [5″,6″:6,7]coumaronochromone and 5,2′,4′-trihydroxy-8-(γ,γ-dimethylallyl)furano [4″,5″:6,7] isoflavone, have been isolated from the stem bark of the Cameroonian medicinal plant, Erythrina senegalensis , in addition to five known pentacyclic triterpenes, β-amyrin, maniladiol, erythrodiol, oleanolic acid and cornulacic acid. Their structures were determined by spectroscopic methods.

Oxidative burst inhibitory and cytotoxic amides and lignans from the stem bark of Fagara heitzii (Rutaceae)

Two amides, heitziamide A and heitziamide B and two phenylethanoids, heitziethanoid A and heitziethanoid B together with thirteen known compounds were isolated from F. heitzii (Letouzey). The structures of all compounds were established by spectroscopic analysis. Nine compounds were evaluated for oxidative burst inhibitory activity in a chemoluminescence assay and for cytotoxicity against PC-3 prostate cancer cells. All compounds exhibited a clear suppressive effect on phagocytosis response upon activation with serum opsonized zymosan at the range of IC(50)=2.0-6.5 microM, but no cytotoxic effect was observed (IC(50)>100 microM).

Anti-inflammatory and Analgesic Effects of Drypemolundein A, a Sesquiterpene Lactone from Drypetes molunduana

Previous pharmacological screening in our laboratory showed analgesic and anti-inflammatory effects of a crude stem bark extract of Drypetes molunduana. Phytochemical studies of this plant led to the isolation an structural elucidation of seven pentacylic triterpenes and one lignan, which were already known compounds, and a new furanosesquiterpene lactone, Drypemolundein A. The purpose of this study was to examine the anti-inflammatory and analgesic activities of drypemolundein A. The compound was studied against carrageenan-induced acute edema. At doses of 10 and 20 mg/kg, orally administered, it significantly reduced (57.57 and 66.66% inhibition at 1 h intervals, respectively) paw edema. At the same doses, this sesquiterpene lactone also exhibited significant analgesic action in force-induced pain in rat paw. These results indicate that drypemolundein A functions as an effective anti-inflammatory and analgesic agent.

Triterpenoids with antimicrobial activity from Drypetes inaequalis

The air-dried stems and ripe fruit of Drypetes inaequalis Hutch. (Euphorbiaceae) were studied. Four triterpene derivatives, characterized as lup-20(29)-en-3beta,6alpha-diol, 3beta-acetoxylup-20(29)-en-6alpha-ol, 3beta-caffeoyloxylup-20(29)-en-6alpha-ol and 28-betad-glucopyranosyl-30-methyl 3beta-hydroxyolean-12-en-28,30-dioate along with 10 known compounds were isolated from the whole stems. One triterpene, characterized as 3alpha-hydroxyfriedelan-25-al along with six known compounds were isolated from the ripe fruit. Their structures were established on the basis of spectroscopic analysis and chemical evidence. The triterpenes were tested for antimicrobial activity against some Gram-positive and Gram-negative bacteria, and two of them appeared to be modestly active.

Sesquiterpene lactone and friedelane derivative from Drypetes molunduana

A new sesquiterpene lactone, drypemolundein A and a new friedelane derivative, drypemolundein B, along with seven known compounds have been isolated from the whole stems of Drypetes molunduana Pax and Hoffm. Their structures were established on the basis of one- and two-dimensional NMR, homo- and hetero-nuclear spectroscopic evidence.

Erythrinasinate, an ester from three Erythrina species

Abstract The novel ester n -octacosanyl-3-hydroxy-4-methoxy cinnamate has been isolated from the stem bark of Erythrina senegalensis , E. glauca and E. mildbaedii and its structure determined by spectroscopic data and degradative studies. The known pterocarpan erythrabyssin-1 has also been isolated from . glauca .

Pentacyclic triterpenoid and saponins from Gambeya boukokoensis.

Chemical studies of the EtOAc extract of Gambeya boukokoensis Aubr. et Pellegr. stem bark led to the isolation of eight compounds. Three of them were elucidated as new compounds and designated as: gamboukokoensein A, 1alpha,2alpha,3beta,19alpha,23-pentahydroxyurs-12-en-28-oic acid; gamboukokoenside A, 2beta,3beta,6beta,28-tetrahydroxyolean-12-en-23-oic acid 23-O-alpha-L-arabinopyranosyl ester and gamboukokoenside B, 6beta,28-dihydroxy-3-oxoolean-12-en-23-oic acid 23-O-alpha-L-arabinopyranosyl ester. The other five compounds were known and identified as myrianthic acid, protobassic acid, oleanolic acid, erythrodiol and chondrillasterol. Their structures were elucidated on the basis of one and two dimensional NMR spectroscopic techniques, FABMS, ESMS and chemical evidence.

Oxidative Burst Inhibitory and Cytotoxic Indoloquinazoline and Furoquinoline Alkaloids from Oricia suaveolens

Two new β-indoloquinazoline alkaloids, orisuaveoline A (1) and orisuaveoline B (2), two new furoquinoline alkaloids, quinosuaveoline A (5) and quinosuaveoline B (6), and 12 known compounds were isolated from Oricia suaveolens. The structures of the new compounds were deduced by spectroscopic studies. The absolute configuration of nkolbisine (4) was also determined. Compounds 2, 3, 6-8, 10, and 14 were evaluated for oxidative burst inhibitory activity in a chemoluminescence assay and for cytotoxicity against A549 lung carcinoma cells.

Erythrisenegalone, a prenylated-flavanone from Erythrina senegalensis☆

Abstract The isolation of a new prenylated flavanone, erythrisenegalone, from the stem-bark of Erythrina senegalensis is described. Its structure was established by spectroscopic methods and a few chemical transformations.

Isoflavones and alkaloids from the stem bark and seeds of erythrina senegalensis

Abstract Two new isoflavones, erysenegalensein L, 5,6′,4′-trihydroxy-8-(2‴-hydroxy-3‴-methylbut-3‴-enyl)-2″,2″-dimethylpyrano [5″,6″,6,7] isoflavone and erysenegalensein M, 5,4′-dihydroxy-8-(2‴-hydroxy-3‴-methylbut-3‴-enyl)-2″, 2″-dimethylpyrano [5″, 6″: 6, 7] isoflavone have been isolated from the stem bark of the Cameroonian medicinal plant Erythrina senegalensis . The seeds of this plant afforded erysodine, glucoerysodine and hypaphorine. Their structures were determined by the usual spectroscopic methods, 2D NMR techniques and were confirmed by chemical reactions.