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See detailMetabolomic investigation of the ethnopharmacological use of Artemisia afra with NMR Spectroscopy and Multivariate Data Analysis.
Liu, N. Q.; Cao, Martine ULg; Frederich, Michel ULg et al

in Journal of Ethnopharmacology (2010), 128

Ethnopharmacological relevance: Artemisia afra has been used as an infusion to treat malaria throughout the southern parts of Africa, in much the same way as the antimalarial plant Artemisia annua in ... [more ▼]

Ethnopharmacological relevance: Artemisia afra has been used as an infusion to treat malaria throughout the southern parts of Africa, in much the same way as the antimalarial plant Artemisia annua in China. The antiplasmodial activity of purified components from an apolar fraction of A. afra has been shown in the past. No data on the efficacy of the tea infusion prepared from A. afra are however available. OBJECTIVE: To investigate the antiplasmodial activity of various extracts of A. afra including an ethnopharmacological prepared sample. To identify polar metabolites in A. afra and A. annua and by using multivariate data analysis investigate the metabolic differences between these species. Materials and methods: The antiplasmodial activity of A. afra and A. annua extracts were tested for activity against Plasmodiam falciparum 3D7 (chloroquine-sensitive strain) with chloroquine, quinine and artemisinin as positive controls. Hydrophilic metabolites in A. afra and A. annua were identified directly from the crude extracts through 1D- and 2D-NMR spectra. The NMR spectra were also used to differentiate between the two species using principal component analysis (PCA) for quality control purposes. RESULTS: The apolar fractions of both A. afra and A. annua showed activity against P. falciparum while activity was only found in the tea infusion of A. annua. Metabolomic studies using 1D- and 2D-NMR spectroscopy identified 24 semi-polar components in A. afra including three new phenylpropanoids for this species: caffeic acid, chlorogenic acid and 3,5-dicaffeoyl quinic acid. PCA analysis conducted on the samples yielded good separation between the polar extracts of A. afra and A. annua. CONCLUSION: These findings shows that there are no in vitro activity in the tea infusion of A. afra and lists the identified metabolites causing the metabolic differences between A. afra and A. annua for quality control purposes. [less ▲]

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See detailAlkaloid accumulation in Catharanthus roseus cell suspension cultures fed with stemmadenine
El-Sayed, M.; Choi, Y. H.; Frederich, Michel ULg et al

in Biotechnology Letters (2004), 26(10), 793-798

Feeding stemmadenine to Catharanthus roseus cell suspension culture resulted in the accumulation of catharanthine, tabersonine and condylocarpine. Condylocarpine is not an intermediate in the pathway to ... [more ▼]

Feeding stemmadenine to Catharanthus roseus cell suspension culture resulted in the accumulation of catharanthine, tabersonine and condylocarpine. Condylocarpine is not an intermediate in the pathway to catharanthine or tabersonine when it is fed to the cultures. The results support the hypothesis that stemmadenine is an intermediate in the pathway to catharanthine and tabersonine. [less ▲]

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See detailNMR assignments of the major Cannabinoids and cannabiflavonoids isolated from flowers of Cannabis sativa
Choi, Y. H.; Hazekamp, A.; Peltenburg-Looman, A. M. G. et al

in Phytochemical Analysis [=PCA] (2004), 15(6, NOV-DEC), 345-354

The complete H-1- and C-13-NMR assignments of the major Cannabis constituents, Delta(9)-tetrahydrocannabinol, tetrahydrocannabinolic acid, A-tetrahydrocannabinol, cannabigerol, cannabinol, cannabidiol ... [more ▼]

The complete H-1- and C-13-NMR assignments of the major Cannabis constituents, Delta(9)-tetrahydrocannabinol, tetrahydrocannabinolic acid, A-tetrahydrocannabinol, cannabigerol, cannabinol, cannabidiol, cannabidiolic acid, cannflavin A and cannflavin B have been determined on the basis of one- and two-dimensional NMR spectra including H-1- and (13)-NMR, H-1-H-1-COSY, HMQC and HMBC. The substitution of carboxylic acid on the cannabinoid nucleus (as in tetrahydrocannabinolic acid and cannabidiolic acid) has a large effect on the chemical shift of H-1" of the C5 side chain and 2'-OH. It was also observed that carboxylic acid substitution reduces intermolecular hydrogen bonding resulting in a sharpening of the H-5' signal in cannabinolic acid in deuterated chloroform. The additional aromaticity of cannabinol causes the two angular methyl groups (H-8 and H-9) to show identical H-1-NMR shifts, which indicates that the two aromatic rings are in one plane in contrast to the other cannabinoids. For the cannabiflavonoids, the unambiguous assignments of C-3' and C-4' of cannflavin A and B were determined by HMBC spectra. Copyright (C) 2004 John Wiley Sons, Ltd. [less ▲]

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See detailQuantitative analysis of strychnine and brucine in Strychnos nux-vomica using H-1-NMR
Frederich, Michel ULg; Choi, Y. H.; Verpoorte, R.

in Planta Medica (2003), 69(12), 1169-1171

A quantitative analysis using H-1-NMR (Q-NMR) has been developed for the determination of strychnine and brucine in Strychnos nux-vomica seeds and stems. The advantages of the method are that no reference ... [more ▼]

A quantitative analysis using H-1-NMR (Q-NMR) has been developed for the determination of strychnine and brucine in Strychnos nux-vomica seeds and stems. The advantages of the method are that no reference alkaloids are needed for calibration curves, the quantification could be directly realized on a crude extract, strychnine and brucine could easily be distinguished, an overall profile of the preparation (including non alkaloid compounds) could be directly obtained, and a very significant time-gain could be achieved, in comparison to conventional HPLC methods, for instance. [less ▲]

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See detailbeta-carboline glucoalkaloids from Strychnos mellodora
Brandt, V.; Tits, Monique ULg; Geerlings, A. et al

in Phytochemistry (1999), 51(8), 1171-1176

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