Kenganthranol F, a new anthranol from Psorospermum aurantiacum.

A new anthranol, kenganthranol F, was isolated from the ethyl acetate extracts of the seeds and the whole plant of the Cameroonian plant Psorospermum aurantiacum (Hypericaceae), together with fifteen known compounds viz., ferruginin B, vismin, vismion D, haronginanthrone, kenganthraquinone, kenganthranol B and kenganthranol E isolated from the fruits and 3-geranyloxyemodinanthrone, 2-geranylemodin, bianthrone A1, vismione D, 1,8-dihydroxy-3-geranyloxy-6-methylanthraquinone, vismione M, vismiaquinone, vismiaquinone C being isolated from the whole plant. The structure of the new isomer of kenganthranol F was determined to be 1,8,10-trihydroxy-3,4-[2,2-dimethyldihydropyrano]-6-methyl-2,5-bis-(3,3-dimethylallyl)-anthrone.

Antitubercular activity of the semi-polar extractives of Uvaria rufa.

OBJECTIVE: To investigate the inhibitory activity of the chloroform extract, petroleum ether and chloroform sub-extracts, lead-acetate treated chloroform extract, fractions and secondary metabolites of Uvaria rufa (U. rufa) against Mycobacterium tuberculosis (M. tuberculosis) H(37)Rv. METHODS: The antituberculosis susceptibility assay was carried out using the colorimetric Microplate Alamar blue assay (MABA). In addition, the cytotoxicity of the most active fraction was evaluated using the VERO cell toxicity assay. RESULTS: The in vitro inhibitory activity against M. tuberculosis H(37)Rv increased as purification progressed to fractionation (MIC up to 23 µg/mL). The chloroform extract and its sub-extracts showed moderate toxicity while the most active fraction from chloroform sub-extract exhibited no cytotoxicity against VERO cells. Meanwhile, the lead acetate-treated crude chloroform extract and its fractions showed complete inhibitions (100%) with MIC values up to 8 µg/mL. Phytochemical screening of the most active fraction showed, in general, the presence of terpenoids, steroids and phenolic compounds. Evaluation of the antimycobacterial activity of known secondary metabolites isolated showed no promising inhibitory activity against the test organism. CONCLUSIONS: The present results demonstrate the potential of U. rufa as a phytomedicinal source of compounds that may exhibit promising antituberculosis activity. In addition, elimination of polar pigments revealed enhanced inhibition against M. tuberculosis H(37)Rv. While several compounds known for this plant did not show antimycobacterial activity, the obtained results are considered sufficient reason for further study to isolate the metabolites from U. rufa responsible for the antitubercular activity.

Villarinol, a new alkenoyloxyalkenol derivative from the endemic Philippine Rubiaceae species Villaria odorata.

Villarinol (1), a new alkenoyloxy alkenol metabolite, has been isolated from the dichloromethane extract of Villaria odorata, an endemic Rubiaceae Philippine plant, along with the known compounds stigmasterol and 4-hydroxybenzaldehyde. The structure of 1 was elucidated on the basis of spectroscopic and spectrometric studies. The extracts of V. odorata exhibited moderate inhibition against Mycobacterium tuberculosis H37Rv, based on the colorimetric microplate alamar blue assay.

Photoactivated [3+2] addition of 6,7-seco-angustilobine B to fullerene [C60].

A synthesis of a new alkaloid-fullerene conjugate (1) is reported. The reaction was carried out by photoinduced [3+2] cycloaddition of the Alstonia indole alkaloid, 6,7-seco-angustilobine B (2), to fullerene[C60] (3) under aerobic conditions. The major monoaddition photoadduct (1) was characterized unambiguously by UV, IR, MALDI-TOFMS and NMR experiments. A mechanism highlighted by sequential photoinduced electron transfer andradical recombination pathways is also proposed. No significant enhancement in inhibition against M. tuberculosis H37Rv was observed for 1 compared with its parent compounds 2 and 3.

Two new antimicrobial metabolites from the endophytic fungus, Seimatosporium sp.

Two new acaranoic acids, named seimatoporic acid A and B (1, and 2), together with six known compounds, R-(-)-mellein (3), cis-4-hydroxymellein (4), trans-4-hydroxymellein (5), 4R-hydroxy-5-methylmellein (6), (-)-5-hydroxymethylmellein (7), and ergosterol (8) were isolated from an endophytic fungus, Seimatosporium sp, by a bioassay-guided procedure. The structures of the new compounds have been assigned from analysis of the 1H and 13C NMR spectra, DEPT, and by 2D COSY, HMQC, HMBC and NOESY experiments. A mixture of compounds 1 and 2 showed strong antifungal activity against Botrytis cinerea, Septoria tritici, and Pyricularia oryzae.

Eucleanal: a new napthalene derivative from Euclea divinorum.

A new naphthalene derivative, named eucleanal (1), was isolated from Euclea divinorum Hiern., and its structure elucidated by detailed spectroscopic (1H, 13C NMR, COSY, HMQC, HMBC) and HREIMS analysis.

Pyrenocines J-M: four new pyrenocines from the endophytic fungus, Phomopsis sp.

Four new pyrenocines, named pyrenocines J-M (1-4), were isolated from an endophytic fungus, Phomopsis sp, by a bioassay-guided method. The structures of the new compound have been assigned from ¹H and ¹³C NMR spectra, DEPT, and by 2D COSY, HMQC, and HMBC experiments. Preliminary studied showed that compounds 1, 2 and 4 showed good antifungal, antibacterial, and algicidal properties, while compound 3 had good antibacterial and algicidal properties.

Drypetdimer A: a new flavone dimer from Drypetes gerrardii.

A new flavone dimer, drypetdimer A (1), was isolated from Drypetes gerrardii J.Hutch The structure of the new compound was elucidated by detailed spectroscopic analysis such as 1H, 13C NMR, COSY, HMQC, HMBC and HREIMS.

Two new alkylanacardic acids, ozorcardic A and B, from Ozoroa pulcherrima.

Two new alkylanacardic acids, ozorcardic A (1) and B (2), along with the known and related metabolite anacardic acid (3), were isolated from Ozoroa pulcherrima. The structures of the new compounds were elucidated by detailed spectroscopic and spectrometric analysis.

Synthesis of a 4H-anthra[1,2-b]pyran derivative and its antimicrobial activity.

The five-step synthesis of the new 4H-anthra[1,2-b]pyran derivative 1 is reported. The key steps in this approach included a Marschalk alkylation of 1,4-dihydroxyanthraquinone followed by a Baker-Venkataraman reaction and then an acid-catalyzed cyclization of ring A to form the 4H-anthra[1,2-b]pyran system. Two compounds, the 4H-anthra[1,2-b]pyran 1 and the anthraquinone derivative 6 were evaluated for antimicrobial activity and showed moderate antialgal, antifungal, and antibacterial activities.

Bioactive aromatic derivatives from endophytic fungus, Cytospora sp.

Two new benzyl gamma-butyrolactone analogues, (R)-5-((S)-hydroxy(phenyl)-methyl)dihydrofuran-2(3H)-one (1) and its 6-acetate (2), and a new naphthalenone derivative (8), together with eight additional known aromatic derivatives, (S)-5-((S)-hydroxy(phenyl)-methyl)dihydrofuran-2(3H)-one (3), (S)-5-benzyl-dihydrofuran-2(3H)-one (4), 5-phenyl-4-oxopentanoic acid (5), gamma-oxo-benzenepentanoic acid methyl ester (6), 3-(2,5-dihydro-4-hydroxy-5-oxo-3-phenyl-2-furyl)propionic acid (7), (3R)-5-methylmellein (9), integracins A (10) and B (11) were isolated from Cytospora sp., an endophytic fungus isolated from Ilex canariensis from Gomera. The structures of these compounds were elucidated by detailed spectroscopic analysis, comparison with reported data, and chemical interconversion. The absolute configurations of the new compounds (1, 2, 8) were established on the basis of optical rotation or CD spectra analysis. Preliminary studies showed antimicrobial activity of these compounds against the fungi Microbotryum violaceum, Botrytis cinerea and Septoria tritici, the alga Chlorella fusca, and the bacterium Bacillus megaterium.

Antimicrobial chemical constituents from the endophytic fungus Phomopsis sp. from Notobasis syriaca.

Phomosine K (1), a new phomosine derivative, has been isolated from Phomopsis sp., in addition to six known compounds: phomosine A (2), phenylalanine amide (3), 2-hydroxymethyl-4beta,5alpha,6beta-trihydroxycyclohex-2-en (4), (-)-phyllostine (5), (+)-epiepoxydon (6), and (+)-epoxydon monoacetate (7). Preliminary studies showed that compound 1 had strong antibacterial activity, while compounds 4-7 showed good antifungal, antibacterial, and algicidal properties, except compounds 4 and 6, which lacked antifungal activity.

Phomosines H-J, novel highly substituted biaryl ethers, isolated from the endophytic fungus Phomopsis sp. from Ligustrum vulgare.

From the endophytic fungus Phomosis sp., four known phomosines A-D (1-4) and three new phomosines H-J (5-7) have been isolated. The structures of the new compounds were determined on the basis of their spectroscopic data analysis (1H, 13C, 1H-1H COSY, HMQC, and HMBC NMR, as well as mass spectrometry). The structures of phomosine H (5) and J (7) were also confirmed by semisynthesis from phomosine A (1). The remaining four known compounds [phomosines A-D (1-4)] were identified by comparing their spectroscopic data with those reported in the literature. The four known metabolites were biologically active. Of the novel metabolites, only 6 was antifungal and antibacterial.

Isolation, structure elucidation, and biological activity of a new alkaloid from Zanthoxylum rhetsa.

Several biologically active alkaloids (1-4, 6), including a new quinazoline-6-carboxylic acid (1), were isolated from the medicinal plant Zanthoxylum rhetsa, an evergreen tree, native to subtropical areas. Whereas the pharmacological properties of the plant extract and single constituents have been widely tested, we now show that all of the metabolites have antialgal activities, all but 6 are antibacterial, and 6 and the reduction product 5 (derived from 4) are also antifungal.

Phytoconstituents from Alpinia purpurata and their in vitro inhibitory activity against Mycobacterium tuberculosis.

Alpinia purpurata or red ginger was studied for its phytochemical constituents as part of our growing interest on Philippine Zingiberaceae plants that may exhibit antimycobacterial activity. The hexane and dichloromethane subextracts of the leaves were fractionated and purified using silica gel chromatography to afford a mixture of C(28)-C(32) fatty alcohols, a 3-methoxyflavone and two steroidal glycosides. The two latter metabolites were spectroscopically identified as kumatakenin (1), sitosteryl-3-O-6-palmitoyl-ß-D-glucoside (2) and b-sitosteryl galactoside (3) using ultraviolet (UV), infrared (IR), electron impact mass spectrometer (EIMS) and nuclear magnetic resonance (NMR) experiments, and by comparison with literature data. This study demonstrates for the first time the isolation of these constituents from A. purpurata. In addition to the purported anti-inflammatory activity, its phytomedicinal potential to treat tuberculosis is also described.

Metabolites from the fungus Phoma sp. 7210, associated with Aizoon canariense.

A new metabolite, 3,16-diketoaphidicolan (1), was isolated together with four known compounds: aphidicolin (2), 17-acetyl-aphidicolin (3), (+)-eupenoxide (4), and phomoxanthone A (5) from the endophytic fungus Phoma sp. The structure of the new compound 1 was determined by spectroscopic methods (mainly extensive 1D and 2D NMR experiments and by mass spectral measurements) and confirmed by X-ray crystallography. Its absolute configuration was assigned by means of the solid-state CD/TDDFT approach comparing the solid-state CD spectrum with the TDDFT-calculated one on the X-ray geometry.

Antimicrobial coumarins from the stem bark of Afraegle paniculata.

Eight compounds were isolated from the stem bark of the plant Afraegle paniculata. One of them, a dimethyl ether of S-trans-marmin (1), is reported as a new natural product. The structures were determined by comprehensive analyses of their 1D and 2D NMR spectroscopic and HREIMS data. The remaining seven known compounds, identified by comparing their spectroscopic data with those reported in the literature, were S-trans-marmin (2), psoralene (3), bergaptene (4), imperatorin (5), 2-(4-hydroxy-3,5-dimethoxyphenyl)-3-hydroxymethyl-2,3-dihydro- 1,4,5-trioxaphenanthren-6-one (6), xanthoxyletin (7), and beta-sitosterol glucopyranoside. Preliminary studies indicated that compounds 2, 3, 5, and 7 showed potent antibacterial, fungicidal, and algicidal properties, while 6 showed only moderate algicidal property.

Hyloglyceride and hylodiglyceride: two new glyceride derivatives from Hylodendron gabunensis.

Phytochemical investigation of Hylodendron gabunensis resulted in the isolation of two new glyceride derivatives, hyloglyceride (1) and hylodiglyceride (2). The structures of the two new compounds were determined by comprehensive analysis of their 1D and 2D NMR spectroscopic, and HREIMS data. One known compound was also isolated and identified as beta-sitosterol.

Pycnangloside: a new cerebroside from bark of Pycnanthus angolensis.

Pycnanthus anglonensis is known for its medicinal value. This paper deals with a phytochemical investigation of this species, from which pycnangloside (1), a new cerebroside has been isolated. Its structure was determined by comprehensive analyses of its 1D and 2D NMR spectroscopic, and ESI mass spectrometric data. Four known compounds were also isolated and identified as biochanin A, formonentin, beta-sitosterol, and beta-sitosterol glucopyranoside.

Antiplasmodial activities of furoquinoline alkaloids from Teclea afzelii.

The study of the chemical constituents of the stem bark of Teclea afzelii (Rutaceae) has resulted in the isolation and characterization of four furoquinoline alkaloids, namely kokusaginine (1), tecleaverdoornine (2), maculine (3) and montrifoline (4) together with lupeol (5) and beta-sitosterol glucopyranoside (6). The structures of the isolated compounds were elucidated based on spectroscopic studies. The antimalarial activity of compounds 1-4 against Plasmodium falciparum in vitro shows partial suppression of parasitic growth.