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Bioassay-guided isolation of two new compounds, 3,4-methylenedioxy-3'-O-methyl-4'-O-glucoside ellagic acid (1) and the pteleoellagic acid derivative (2), from the stem bark of Pteleopsis hylodendron is reported along with 3,4-methylenedioxy-3'-O-methyl ellagic acid (3), 3,3'-di-O-methyl ellagic acid (4) and 3,3',4'-tri-O-methyl ellagic acid (5), which were obtained for the first time from this plant. The structures of these compounds were elucidated with the help of spectroscopic studies. Compounds 1 and 4 were found to have significant antioxidant activity, while compounds 1-4 showed antibacterial activity against different pathogenic bacteria.

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Investigations of the stem and root bark of Myrica arborea (Myricaceae) have yielded two novel diarylheptanoids, myricarborin and 11-O-beta-D-xylopyranosylmyricanol along with the known myricanol and 5-O-beta-D-glucopyranosylmyricanol. The structures of the novel compounds were determined by spectroscopic methods.

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A new Diels-Alder-type adduct, dorstenone (1), was isolated from Dorstenia barteri together with three known flavonoids, 4,2', 4'-trihydoxy-3'-prenylchalcone; 4,2',4'-trihydoxy-3, 3'-diprenylchalcone; and 5,7,4'-trihydoxy-8-prenylflavone. The structure of 1 was elucidated using a combination of highfield NMR techniques, particularly, gradient-enhanced HMQC and HMBC.

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Four urea derivatives were isolated from the roots of Pentadiplandra brazzeana, and their structures were elucidated by spectroscopic techniques. N-Benzyl-N'-(4-methoxybenzyl)urea (1) is a new compound, although N,N'-di-(4-methoxybenzyl)urea (2), N,N'-dibenzylurea (3), and p-methoxythiobenzaldehyde (4) are reported from a natural source for the first time.

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A new isodaucane sesquiterpenoid, 6,7,10-trihydoxyisodaucane, was isolated from the fruits of Reneilmia cincinnata, together with the known sesquiterpenoids oplodiol, oplopanone, 5E,10(14)-germacradien-1 beta, 4 beta-diol, 1(10)E,5E-germacradien-4 alpha-ol and eudesman-1,4,7-triol. A large amount of 5-hydroxy-3,7,4'-trimethoxyflavone was also isolated. Their structures were established by NMR techniques using 1D and 2D experiments. Three of the known sesquirernenoids exhibited noteworthy anti-plasmodial activity against Plasmodium falciparum strains.

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Three new labdane diterpenes, 12 alpha,17-epoxy-3 beta-hydroxy-8(9),13- labdadien-16,15-olide (aulacocarpinolide) [1], methyl 8 beta,17:14 zeta,15-diepoxy-3 beta-hydroxy- 12E-labden-16-oate (aulacocarpin A) [2], and methyl 8 beta,17:14 zeta,15-diepoxy-3 beta,6 beta- dihydroxy-12E-labden-16-oate (aulacocarpin B) [3] have been isolated from the Cameroonian spice, Aframomum aulacocarpos, and their structures elucidated using spectroscopic techniques. The known bioactive diterpene dialdehyde, 8 beta,17-epoxy-12E-labdene-15,16-dial (aframodial) [4] was also isolated. Compounds 1-3 showed weak antimicrobial and cytotoxic activities.

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Six pentacyclic triterpenic acid methyl esters have been isolated from the methylated ethyl acetate extract of the trunk wood of MUSANGA CECROPIOIDES, as well as a triterpene saponin of the same group. One of them, cecropic acid methyl ester, is new. The structures of these compounds have been established from interpretation of spectral data or chemical transformations. The known triterpenes include euscaphic and tormentic acid methyl esters, already isolated from the root wood of the plant, methyl cecropiaceate, and methyl pomolate, already obtained from the stem bark, and methyl arjunolate and beta- D-glucosyl tormentate, encounted in this plant for the first time.

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Suitable drugs for the elimination of adult Onchocerca volvulus are still needed since ivermectin, the new microfilaricide, appears to be ineffective against this parasite stage. Herein we report on the identification of filaricides in three medicinal plants. The compounds carapolide A, mexicanolide-methylangolensate mixture from Carapa procera and oliverine from Polyalthia suaveolens or Pachypodanthium staudtii when tested at 10-100 micrograms.ml-1 were found to exhibit considerable microfilaricidal activity after 24 hours of incubation. Oliverine was found to be filaricidal when tested against adult female worms at 100 micrograms.ml-1. Preliminary toxicity studies in mice showed carapolide A and the mexicanolide-methylangolensate mixture to be relatively non-toxic, whereas, oliverine had a minimal lethal dose of 8 mg.Kg-1 of body weight. Based on the above results further pharmacologic studies are recommended to determine, the potential application of the active compounds on the treatment of onchocerciasis.

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Two new chromone glycosides, schumanniofiosides A and B have been isolated from the root bark of Schumanniophyton magnificum and their structures shown to be 2-methyl-5,7-dihydroxychromone 5-O-beta-D-glucopyranoside and 2-methyl-5,7-dihydroxychromone 7-O-beta-D-glucopyranosyl-(1----2)-apiofuranoside, respectively. The structures were elucidated by a combination of spectral data and chemical degradation.

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The stem bark of Teclea ouabanguiensis has yielded six triterpenoids, two of which are new. The known compounds were identified spectroscopically as 7-deacetylazadirone (2), 7-deacetylproceranone (3), tecleanin, (4), and lupeol. The novel compounds include the tetranortriterpenoids, 7-deacetoxy-7-oxoazadirone (1), and ouabanginone (5). The biogenetic significance of the presence of these limonoids in T. ouabanguienis is discussed.

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