André Cavé

Biological and chemical studies of Pera benensis, a Bolivian plant used in folk medicine as a treatment of cutaneous leishmaniasis

The stem barks of Pera benensis are employed by the Chimane Indians in the Bolivian Amazonia as treatment of cutaneous leishmaniasis caused by the protozoan Leishmania braziliensis. The chloroform extracts containing quinones were found active against the promastigote forms of Leishmania and the epimastigote forms of Trypanosoma cruzi at 10 micrograms ml-1. The activity guided fractionation of the extract by chromatography afforded active compounds. Their structures were elucidated, by spectral and chemical studies, as known naphthoquinones, plumbagin, 3,3-biplumbagin, 8-8-biplumbagin, and triterpene, lupeol. The activity in vitro of each compound was evaluated against 5 strains of Leishmania (promastigote), 6 strains of Trypanosoma cruzi (epimastigote) and the intracellular form (amastigote) of Leishmania amazonensis. The baseline drugs used were Glucantime and pentamidine (Leishmania spp.), nifurtimox and benznidazole (T. cruzi). Plumbagin was the most active compound in vitro. This study has demonstrated that Pera benensis, a medicinal plant used in folk medicine, is an efficient treatment of cutaneous leishmaniasis.

Produits neutres et alcaloides de Myrtopsis macrocarpa, M. myrtoidea, M. novae-caledoniae et M. sellingii☆

Abstract Stems and leaves of Myrtopsis macrocarpa, M. myrtoidea, M. novae-caledoniae and M. sellingii yielded terpenes, sterols, coumarins, alkaloids (furoquinolines and quinolones) and amides. A new quinolone (8-methoxy flindersine) occurs in Myrtopsis macrocarpa, a new amide (N-benzoyltryptamine) in M. myrtoidea, two new coumarins (myrsellin and myrsellinol) and a new dihydrofuroquinoline (myrtopsine) in M. sellingii. Structures of the new compounds are proposed from chemical and spectroscopic evidence.

Alcaloides d'Araliopsis soyauxii. Isolement d'un nouvel alcaloide, l'Araliopsine

Abstract Six alkaloids have been isolated from root bark of Araliopsis soyauxii . Five are known, maculine, flindersiamine, skimmianine, (−) ribalinine, (+) isoplatydesmine and the sixth, araliopsine is new; its structure has been established as hydroxyisopropyldihydrofuro-2-quinolone. From the trunk bark four alkaloids have been isolated: flindersiamine, kokusaginine (−) ribalinine, (+) isoplatydesmine.

Triterpenes from Prunus africana bark

A chloroformic extract of barks of Prunus africana was found to contain triterpenic acids including derivatives of ursolic and oleanolic acids. Among them 24-O-trans-ferulyl-2α,3α-dihydroxy-urs-12-en-28-oic acid, an original compound, was isolated. Their structure was established by chemical and spectral analysis.

In vitro and in vivo leishmanicidal studies of Peperomia galioides (Piperaceae)

Petroleum ether and methylene chloride extracts of Peperomia galioides and three prenylated diphenols, grifolic acid, grifolin and piperogalin exhibited in vitro antileishmanial activity. During the course of infection of BALB/c mice with Leishmania amazonensis, the treatments with each of these compounds did not influence the progression of the disease.

Annoglaucin, an acetogenin from Annona glauca☆

Abstract Annoglaucin, a new bis-tetrahydrofuran acetogenin was isolated and characterized, in addition to the known compound, rolliniastatin-2, from the roots of Annona glauca .

Alkaloidal and other constituents of Uncaria elliptica and canthium dicoccum

Abstract A new alkaloid roxburghine X, along with roxburghine D, formosanine and mitraphylline, has been isolated from the bark of Uncaria elliptica. Sitosterol, quinovaic acid, acetylquinovaic acid and scopoletin were isolated from the bark of Canthium dicoccum.

Cohibins A and B, acetogenins from roots of Annona muricata☆

Abstract Cohibins A and B, Biogenetic intermediates of acetogenins, were characterized using tandem mass spectrometry (MS/MS) from the roots of Annona muricata.

Radical Scavenging Evaluation of Green Tea Extracts

The free radical scavenging activity of Thea sinensis leaf extract was evaluated with a chemical test involving diphenylpicrylhydrazyl radical (DPPH). The hot aqueous green tea extract demonstrated antiradical activity comparable with rutin and vitamin E used as a standard. Liquid–liquid fractionation monitored by scavenging radical bioassay followed by preparative high pressure liquid chromatography led to catechin derivatives. The antiradical activity of the main component of tea leaves was identified as epigallocatechin gallate the major component demonstrating activity.

Four New Acetogenins from the Seeds of Annona reticulata 1

Abstract Four new acetogenins, dieporeticanin-1 and -2 (1 and 2 respectively), dieporeticenin (3) and trieporeticanin (4) were isolated, with the known diepomuricanin (5), from the seeds of the vietnamese Annonaceae, Annona reticulata. Their structures were elucidated on the basis of the spectral data. Biomimetic hemi-synthesis of reticulatacin (6), solamin (7) from dieporeticanin-1 (1), diepomuricanin (5) respectively, sustains the key role of such natural precursors in the biogenesis of acetogenins.