Contortamide, a new anti-colon cancer cerebroside and other constituents from Tabernaemontana contorta Stapf (Apocynaceae).

A new cerebroside, Contortamide (1) together with nine known compounds spegatrine (2), affinisine (3), Nb-methylaffinisine (4), ursolic acid (5), α-amyrin (6), bauerenol acetate (7), lupeol (8), betulinic acid (9) and ß-sitosterolglycoside (10) were isolated from the trunk bark of Tabernaemontana contorta Stapf. The new compound 1 showed significant activity against Caco-2 colon cancer cells with the MTT method. Compounds 1-4 and 6-9 were isolated for the first time from this species.

Carbazole-, Aspidofractinine-, and Aspidocarpamine-Type Alkaloids from Pleiocarpa pycnantha.

Three new alkaloids, janetinine (1a), pleiokomenine A (2), and huncaniterine B (3a), and 13 known compounds, pleiomutinine (3b), huncaniterine A (3c), 1-carbomethoxy-ß-carboline (4), evoxanthine (5), deformyltalbotine acid lactone (6), pleiocarpamine (7), N4-methyl-10-hydroxygeissoschizol (8), spegatrine (9), neosarpagine (10), aspidofractinine (11), N1-methylkopsinin (12), pleiocarpine (13), and N1-methylkopsinin- N4-oxide (14), were isolated from the stem bark of Pleiocarpa pycnantha. Janetinine (1a) is a carbazole alkaloid; in pleiokomenine A (2), two aspidofractinine-type alkaloids are bridged by a methylene unit in an unprecedented way, and huncaniterine B (3a) is a pleiocarpamine-aspidofractinine-type dimer. The structures and relative configurations of these compounds were elucidated on the basis of NMR and MS analyses. Their absolute configurations were defined by means of experimental and calculated ECD data, and additionally, the structures of 5 and 13 were determined by single crystal X-ray diffraction. Compounds 1a, 2, 3b, 4, 6, 9, and 12 displayed cancer chemopreventive properties through either quinone reductase induction ( CD = 30.7, 30.2, 29.9, 43.5, and 36.7 µM for 1a, 4, 6, 9, and 12, respectively) and/or NF-κB inhibition with IC50 values of 13.1, 8.4, 9.4, and 8.8 µM for 2, 3b, 6, and 12, respectively.

Alternating isocratic and step gradient elution high-speed counter-current chromatography for the isolation of minor phenolics from Ormocarpum kirkii bark.

A total of 14 compounds were isolated from the ethanol bark extract of O. kirkii S. Moore (Fabaceae) by alternating isocratic and step gradient elution high-speed counter-current chromatography (HSCCC) methods, using several solvent systems with reference to the polarity of compounds being purified. The extract was successively fractionated with generic solvent systems including n-hexane-ethanol-water (4:2:2) and ethyl acetate-water (1:1). Resulting fractions were further purified using the following preparative gradient elution consisting of ethyl acetate-n-butanol-water (X:Y:10), (X:Y=9:1 (I); 8:2 (II); 7:3 (III); 6:4 (IV); 5:5 (V); 4:6 (VI) 3:7 (VII) and n-hexane- ethyl acetate-methanol-water (1:X:1:1), X=1, 2, 2.5, 3 solvent systems. Two flavone glycosides, apigenin-6-C-ß-d-glucopyranosyl-4'-O-[ß-d-glucopyranosyl-(1→5)]-ß-d-apiofuranoside (1) and apigenin-6-C-ß-d-glucopyranosyl-4'-O-ß-d-apiofuranoside (2), and one biflavanone diglycoside 7,7″-di-O-ß-d-glucosylliquiritigeninyl-(I-3,II-3)-naringenin (4) were isolated as new compounds along with other 11 known ones. The structures of the isolated compounds were identified by HPLC-UV, ESI-MS, 1D and 2D NMR and comparison with literature data. Thus, over common traditional chromatographic methods, the present study shows that HSCCC is a useful and fast method for natural product research with no losses and lower solvent use.

Cytotoxic flavonoids and other constituents from the stem bark of Ochna schweinfurthiana.

Seven flavonoids, hemerocallone (1), 6,7-dimethoxy-3',4'-dimethoxyisoflavone (2), amentoflavone (4), agathisflavone (6), cupressuflavone (8), robustaflavone (9) and epicatechin (10), together with three other compounds, lithospermoside (3), ß-D-fructofuranosyl-α-D-glucopyranoside (5) and 3ß-O-D-glucopyranosyl-ß-stigmasterol (7), were isolated from the ethyl acetate extract of the stem bark of Ochna schweinfurthiana F. Hoffm. All the compounds were characterised by spectroscopic and mass spectrometric methods, and by comparison with literature data. Cytotoxicity of the extracts and compounds against cervical adenocarcinoma (HeLa) cells was evaluated by MTT assay. Compounds 4 and 6 exhibited good cytotoxic activity, with IC50 values of 20.7 and 10.0 µM, respectively.

A new C-glucosylflavone from Sorindeia juglandifolia.

Phytochemical investigation of the leaves of Sorindeia juglandifolia A. Rich. led to the isolation and identification of a new C-glucosylflavone, 2",6"-di-O-acetyl-7-O-methyl vitexin (1), together with seven known compounds, 2"-O-acetyl-7-O-methyl vitexin (2), mearnsitrin (3), robustaflavone (4), 3-O-galloyl catechin (5), tachioside (2-methoxy-benzene-1,4-diol-1-O-beta-glucopyranoside) (6), 3beta-O-D-glucopyranosyl-beta-stigmasterol (7), and methyl gallate (8). The structures of 1 and the known compounds were established by IR, UV, MS, 1D, and 2D NMR spectra and by comparison with those of related compounds.

The in-vitro antimicrobial activity of some medicinal plants against beta-lactam-resistant bacteria.

BACKGROUND: In effort to identify novel bacterial agents, this study was initiated to evaluate the antimicrobial properties of 17 crude extracts from 12 medicinal plants against beta-lactam-resistant bacteria. METHODOLOGY: The antimicrobial activities of plant extracts were evaluated against clinically proved beta-lactam-resistant bacteria (Klebsiella pneumoniae, Klebsiella oxytoca, Enterobacter cloacae, Serratia marcescens, Acinetobacter baumannii, Staphylococcus aureus and Enterococcus sp.) and reference strains of bacteria (Escherichia coli ATCC 35218, Enterobacter aerogenes ATCC 29751, E. aerogenes ATCC 13048, Pseudomonas aeruginosa ATCC 27853 and Enterococcus hirae ATCC 9790) by using disc-diffusion and agar-dilution assays. RESULTS: The crude plant extracts demonstrated broad spectrum activity against all bacteria tested with inhibition zones in the range of 8-30 mm. The minimal inhibitory concentration (MIC) values of different plant extracts against the tested bacteria were found to range from or= 10 mg ml(-1). The most active plant extracts were from Dortenia picta and Bridelia micrantha (MIC: 1.25-10 mg ml(-1)) on beta-lactam-resistant Gram-negative bacilli and the extracts from B. micrantha, Mallotus oppositifolius, Garcinia lucida, Garcinia. kola, Campylospermum densiflorum (leaves) and C. zenkeri (root) on beta-lactam-resistant Gram-positive cocci (MIC: