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Two new sphingolipids mucusamide (1) and mucusoside (2) have been isolated from methanol soluble part of the stem bark of Ficus mucuso WELW., together with fifteen known secondary metabolites including cellobiosylsterol (3), β-sitosterol (4), stigmasterol (5), β-sitosterol 3-O-β-D-glucopyranoside (6), lupeol acetate (7), ursolic acid (8), procatechuic acid (9), 2-methyl-5,7-dihydroxychromone 8-C-β-D-glucoside (10), apigenin (11), (-)-epicatechin (12), (+)-catechin (13), N-benzoyl-L-phenylalanilol (14), α-acetylamino-phenylpropyl α-benzoylamino-phenylpropionate (15), asperphenamate (16) and bejaminamide (17). Structures of compounds 1 and 2 were elucidated by spectroscopic analysis and chemical methods.

Febrifuquinone (1), a new vismione-anthraquinone coupled pigment and a new bianthrone named adamabianthrone (2), were isolated respectively, from the roots of Psorospermum febrifugum and from the bark of Psorospermum adamauense along with eight known compounds including: two bianthrones [(bianthrone A(1) (3) and bianthrone A(2b)], one vismione [(vismione D (4)], one anthrone (3-geranyloxyemodin anthrone) and four anthraquinones [(1,8-dihydroxy-3-isoprenyloxy-6-methylanthraquinone, emodin (5), 3-geranyloxy-1,8-dihydroxy-6-methylanthraquinone and 2-geranyl-1,8-dihydroxy-6-methylanthraquinone]. Their structures were determined using modern spectroscopic methods including one and two dimensional-NMR techniques as well as MS. Compounds 1 and 2 showed significant antimicrobial activities against a wide range of bacteria and fungi.

In our continuous search for alpha-glucosidase inhibitors from plants, four new depsidones named brevipsidones A-D (1-4) were isolated from stem bark of Garcinia brevipedicellata together with known damnacanthal, scopoletin and a mixture of stigmasterol and beta-sitosterol. Structural elucidations were made by spectroscopic analyses including 2D-NMR data.

From the ethyl acetate extract of the stem bark of Endodesmia calophylloides (Guttiferae), a novel friedelane triterpenoid named endodesmiadiol (1), as well as the known compounds friedelin (2), canophyllol (3), canophyllal (4), cerin (5), morelloflavone (6), volkensiflavone (7), 8-deoxygartanin (8), 3 beta-acetoxyoleanolic acid (9) and 1,8-dihydroxy-3-isoprenyloxy-6-methylxanthone (10) have been isolated. The structures of these compounds were established by spectroscopic analysis, and the relative configuration of endodesmiadiol (1) was confirmed by X-ray diffraction. The antiplasmodial activity of the isolated compounds was evaluated against the W2 strain of Plasmodium falciparum which is resistant to chloroquine and other antimalarial drugs. All the compounds were found to be active with IC50 values ranging from 7.2 to 23.6 microM. The IC50 of endodesmiadiol was found to be 11.8 microM.

Glaberianthrone (1), a new bianthrone was isolated from the hexane extract of the stem bark of Psorospermum glaberrimum together with thirteen known compounds: 3-geranyloxyemodin anthrone (2), friedelan-3-one (3), 3-prenyloxyemodin anthrone (4), 3-geranyloxyemodin (5), 3-prenyloxyemodin (6), friedelan-3-ol (7), acetylvismione D (8), betulinic acid (9), 2-geranylemodin (10), bianthrone A2b (11), bianthrone 1a (12), emodin (13) and 2-prenylemodin (14). The structures of the isolated compounds were established by means of spectroscopic methods. The extracts and the isolated compounds were tested in vitro for their anti-plasmodial activity against Plasmodium falciparum (chloroquine resistant strain W2) and for their acetyl- and butyrylcholinesterase inhibitory properties. The n-hexane extract showed good anti-plasmodial activity against P. falciparum W2 strain, with IC(50) of 0.87 microg/ml. It also exhibited 65.5% and 98.2% of acetyl- and butyrylcholinesterase inhibition at 0.2 mg/ml, respectively. Compounds 2 and 8 showed the best potencies against P. falciparum W2 strain with IC(50) of 1.68 microM and 0.12 microM, (0.66 microg/ml and 0.054 microg/ml) respectively. All tested compounds showed good butyrylcholinesterase inhibition activities with compound 12 displaying the best potency (IC(50) 9.25+/-0.25 microM). All the tested compounds showed weak inhibitory activity against acetylcholinesterase.

Bazouanthrone (1), a new anthrone derivative, has been isolated from the root bark of Harungana madagascariensis, together with known compounds, feruginin A (2), harunganin (3), harunganol A (4), harunganol B (5), friedelan-3-one (6) and betulinic acid (7). The structure of the compound (1) was assigned as 3,5,8,9-tetrahydroxy-2,4,4-tri-(3,3-dimethylallyl)-6-methyl-1-(4H)-anthracenone, by means of spectroscopic analysis. The anti-plasmodial activity of the isolated compounds was evaluated in culture against W2 strain of Plasmodium falciparum. All the compounds were found to be active against the Plasmodium parasites with bazouanthrone (1) showing particular potency (IC50=1.80 microM).