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Three new prenylated furoquinoline alkaloids named lecomtequinoline A (1), B (2), and C (3), togetherwith the known compounds anhydroevoxine (4), evoxine (5), dictamnine (6),N-methylflindersine (7), evoxanthine (8), hesperidin, lupeol, b-sitosterol, stigmasterol, b-sitosterol-3-O-b-D-glucopyranoside, stearic acid, andmyristyl alcohol, were isolated by bioassay-guided fractionation of themethanolic extracts of leaves and stem of Vepris lecomteana. The structures of compounds were determined by spectroscopic methods (NMR,MS, UV, and IR) and by comparisonwith previously reported data. Crude extracts of leaves and stem displayed high antimicrobial activity, with Minimum Inhibitory Concentration (MIC) (values of 10.1-16.5 and 10.2-20.5 µg/mL, respectively), against Escherichia coli, Bacillus subtilis, Pseudomonas agarici, Micrococcus luteus, and Staphylococcus warneri,while compounds 1-6 showed values ranging from11.1 to 18.7 µg/mL or were inactive, suggesting synergistic effect. The extracts may find application in crude drug preparations in Western Africawhere Vepris lecomteana is endemic, subject to negative toxicity results in vivo. [ABSTRACT FROM AUTHOR]

A new prenylated acridone alkaloid, medicacridone (1), and a new ferulate xanthone, medicaxanthone (5), together with 11 known compounds were isolated from the methanol extract of the bark of the Cameroonian medicinal plant Citrus medica. The structures of all compounds were determined by comprehensive analyses of their 1D and 2D NMR, mass spectral (EI and ESI) data, chemical reactions, and comparison with previously known analogues. The agar diffusion test delivered low to missing antimicrobial activities, corresponding with MICs > 1 mg mL–1, while compounds 1–6 and atalantoflavone (9) displayed weak cytotoxic activity against the human Caucasian prostate adenocarcinoma cell line PC-3, with IC50 values ranging from 60.5 to 80.0 μm versus doxorubicine with IC50=0.9 μm. [ABSTRACT FROM AUTHOR]

The chemical investigation of the methanol root extract of Artocarpus heterophyllus Lam. led to the isolation of a new prenylated flavanone, 5,7,4'-trihydroxy-3'-(3-methylbuta-1,3-dienyl)-5'-(3-methylbut-2-enyl)flavanone, trivially named maghamesin ( 1 ), together with nine known compounds, 5-hydroxy-3',4',5',7-tetramethoxy-8-prenylflavanone ( 2 ), cycloheterophyllin ( 3 ), cyclomorusin ( 4 ), isobavachalcone ( 5 ), trans -isoferulic acid ( 6 ), 24-methylenecycloartan-3α-ol ( 7 ), stigmasterol ( 8 ), β -sitosterol ( 9 ) and β -sitosterol-3- O - β -D-glucopyranoside ( 10 ). The structures of the isolates were elucidated by extensive spectroscopic and spectrometric analyses (1D and 2D NMR, ESI-MS) and by comparison with previously reported data. The absolute configuration of 1 was deduced by comparison of its experimental CD with that of a reported similar compound. Compounds 1-3 and 6-7 were tested for their antibacterial and antifungal activities. Compound 1 displayed a significant antibacterial activity against Staphylococcus aureus with MIC value of 15.625  μ g/mL. The others tested compounds showed moderate antibacterial and antifungal activities against several microorganisms with MIC values of either 31.25 or 62.5 μg/mL.

Two new O-prenylated acridone alkaloids, balsacridone A (1) and B (2), together with eighteen known compounds were isolated from the methanol extract from the stems of Balsamocitrus paniculata, a Cameroonian medicinal plant. The structures of all compounds were determined by comprehensive analyses of their 1D and 2D NMR, mass spectral (EI and ESI) data, and chemical reactions. N-methyl-6-methoxybenzoxazolinone (16) was isolated for the first time from a natural source while compounds 13, 14, and 15 for the first time from this genus. Pure compounds were tested for their activity against bacteria, fungi, and plant pathogen oomycetes, using the paper disk agar diffusion assay. The agar diffusion test delivered low to missing antimicrobial activities, corresponding to MICs > 1 mg/mL. However, compounds 1-15 exhibited a strong suppressive effect on phagocytosis response upon activation with serum opsonized zymosan in the range of IC50 = 0.5-7.2 μM, and the acridone alkaloids (1-5), N-trans-p-coumaroyltyramine (13), and N-trans-pcoumaroyloctopamine (14) displayed weak cytotoxic activity against the human Caucasian prostate adenocarcinoma cell line PC-3, with IC₅₀ values ranging from 69.8 to 99.0 μM., (© Georg Thieme Verlag KG Stuttgart · New York.)