Cranberry Xyloglucan Structure and Inhibition of Escherichia coli Adhesion to Epithelial Cells.

Cranberry juice has been recognized as a treatment for urinary tract infections on the basis of scientific reports of proanthocyanidin anti-adhesion activity against Escherichia coli as well as from folklore. Xyloglucan oligosaccharides were detected in cranberry juice and the residue remaining following commercial juice extraction that included pectinase maceration of the pulp. A novel xyloglucan was detected through tandem mass spectrometry analysis of an ion at m/z 1055 that was determined to be a branched, three hexose, four pentose oligosaccharide consistent with an arabino-xyloglucan structure. Two-dimensional nuclear magnetic resonance spectroscopy analysis provided through-bond correlations for the α-L-Araf (1→2) α-D-Xylp (1→6) ß-D-Glcp sequence, proving the S-type cranberry xyloglucan structure. Cranberry xyloglucan-rich fractions inhibited the adhesion of E. coli CFT073 and UTI89 strains to T24 human bladder epithelial cells and that of E. coli O157:H7 to HT29 human colonic epithelial cells. SSGG xyloglucan oligosaccharides represent a new cranberry bioactive component with E. coli anti-adhesion activity and high affinity for type 1 fimbriae.

Antiplasmodial activity of (I-3,II-3)-biflavonoids and other constituents from Ormocarpum kirkii.

Preliminary screening of a series of medicinal plants, traditionally used in Tanzania, showed an IC(50) of 15.6-31.2 microg/ml for the crude extract of the root of Ormocarpum kirkii S. Moore (Papilionaceae) against Plasmodium falciparum. A bioguided isolation was performed in order to isolate the active constituents. Twelve constituents were obtained and identified using NMR and MS data, and optical rotation measurements. The compounds comprised seven (I-3,II-3)-biflavonoids, three (I-3,II-3)-bi-4-phenyldihydrocoumarins, an isoflavanone and a C-glucosylated flavone. Six compounds, liquiritigeninyl-(I-3,II-3)-naringenin, apigeninyl-(I-3,II-3)-naringenin, 7-O-beta-D-glucopyranosylchamaejasmin, (3R,4S,3''R,4''S)-5,5''-di-O-methyldiphysin, 7-O-beta-D-glucopyranosyldiphysin, and 4''-hydroxydiphysolone, were isolated in addition to six known components. The compounds were evaluated for antimicrobial activity in a broad screening panel, including P. falciparum. Seven of these showed antiplasmodial activity; isochamaejasmin being the most active with an IC(50) of 7.3+/-3.8 microM, but the selectivity was rather limited. Thus, these constituents may contribute, at least in part, to the antimalarial use of O. kirkii in traditional medicine.

Phytochemical investigation of Cycas circinalis and Cycas revoluta leaflets: moderately active antibacterial biflavonoids.

Chemical examination of the methanolic extract of the leaflets of CYCAS CIRCINALIS L. led to the isolation of one new biflavonoid, (2 S, 2'' S)-2,3,2'',3''-tetrahydro-4',4'''-di- O-methylamentoflavone (tetrahydroisoginkgetin; 2), and 15 known compounds, 11 of which are reported for the first time from C. CIRCINALIS. Chromatographic separation of the chloroform extract of C. REVOLUTA Thunb. leaflets afforded 12 compounds, seven of which are reported for the first time from this species. The isolated compounds from both species include 14 biflavonoids, three lignans, three flavan-3-ols, two flavone- C-glucosides, two NOR-isoprenoids, and one flavanone. This is the first report of NMR and CD data of 2,3,2'',3''-tetrahydro-4'- O-methyl- and 2,3-dihydro-4'- O-methyl-amentoflavone ( 6) and ( 7). The effect of O-methylation on the chemical shifts of the neighboring carbons in the (13)C NMR spectra of the dihydro- and tetrahydro-amentoflavone skeletons provides a tool to identify the location of the methoxy groups. Compounds 2, 6, and 18 displayed moderate antibacterial activity against STAPHYLOCOCCUS AUREUS (IC (50) values of 3.9, 9.7, and 8.2 microM, respectively) and methicillin-resistant S. AUREUS (MRSA; IC (50) values of 5.9, 12.5, and 11.5 microM, respectively).

Antiparasitic activity of some xanthones and biflavonoids from the root bark of Garcinia livingstonei.

A new biflavanoid, ent-naringeninyl-(I-3alpha,II-8)-4'-O-methylnaringenin (6), along with five known xanthones and two known biflavonoids, was isolated from the root bark of Garcinia livingstonei collected in Tanzania. The absolute configuration of 6 was established by CD spectroscopy. This compound showed moderate activity against P. falciparum (IC(50) 6.7 microM). Antitrypanosomal activity (IC(50) 0.87 microM) was observed for 1,4,5-trihydroxy-3-(3-methylbut-2-enyl)-9H-xanthen-9-one (3). The dimeric xanthone garcilivin A (4) showed a higher and nonselective antiparasitic activity and cytotoxicity (IC(50) 2.0 microM against MRC-5 cells) than its diastereoisomer garcilivin C (5) (IC(50) 52.3 microM).

Syncarpamide, a new antiplasmodial (+)-norepinephrine derivative from Zanthoxylum syncarpum.

A new (+)-norepinephrine derivative, syncarpamide (1), along with a known coumarin, (+)-S-marmesin (2), and one known alkaloid, decarine (3), have been isolated from the stem of Zanthoxylum syncarpum. The structure of compound 1 was elucidated on the basis of 1D and 2D NMR, MS, IR, optical rotation, and CD analyses. Its absolute stereochemistry was elucidated by synthesis of its enantiomer and subsequent comparison of CD data. Characterizations of compounds 2 and 3 were based on spectral analysis and comparison with reported data. Compounds 1 and 3 showed antiplasmodial activity, with IC(50) values of 2.04 and 1.44 microM against Plasmodium falciparum D(6) clone and 3.06 and 0.88 microM against P. falciparum W(2) clone, respectively. Compound 3 showed cytotoxicity at 56.42 microM, whereas compound 1 was not cytotoxic at 10.42 microM. Compound 1 was tested for hypotensive activity, but no activity was observed. Compound 2 showed no antiplasmodial or antimicrobial activities.