Subject(s)
Flavonoids/chemistry , Ziziphus/chemistry , Chloroform , Flavonoids/isolation & purification , Glycosides , Hexanes , Magnetic Resonance Spectroscopy , Models, Molecular , Molecular Conformation , Plant Leaves/chemistry , Solvents , Spectrometry, Mass, Electrospray Ionization , Spectrophotometry, UltravioletABSTRACT
The antiplasmodial activity of twelve alkaloids with an aspidospermane skeleton was estimated in vitro on chloroquine-resistant and sensitive strains of Plasmodium falciparum. Seven tetracyclic alkaloids possessing a free ethyl chain such aspidospermine, showed IC50 after incubation for 72 h between 3.2 and 15.4 microM. Moreover, four pentacyclic alkaloids with ethyl chain included in a tetrahydrofuran, such haplocine, showed a reduced activity, with IC50, after 72 h, between 22.6 and 52.6 microM. According to these results, a chloroquine-potentiating experiment was also performed with two of the most active compounds. Isobolograms were obtained and demonstrated a synergic effect of N-formyl-aspidospermidine and aspidospermine when associated with chloroquine. The cytotoxicity and the selectivity index of some alkaloids were also estimated.
Subject(s)
Antimalarials/pharmacology , Aspidosperma , Indole Alkaloids/pharmacology , Plasmodium falciparum/drug effects , Quinolines , Alkaloids/pharmacology , Animals , Antimalarials/chemistry , Cell Line , Chloroquine/pharmacology , Drug Resistance , Humans , Hypoxanthine/pharmacology , Indole Alkaloids/chemistry , Indoles/pharmacology , Inhibitory Concentration 50 , Molecular Structure , Plant Extracts/chemistry , Plant Extracts/pharmacology , Structure-Activity Relationship , Toxicity TestsABSTRACT
The isolation of 14 known triterpenoids and phytosterols from the trunk bark of Maquira coriacea, and complete spectral data of a cardenolide, k-strophanthin-beta (1), are reported.
Subject(s)
Cardenolides/chemistry , Moraceae , Phytotherapy , Plant Extracts/chemistry , Triterpenes/chemistry , Humans , Magnetic Resonance SpectroscopyABSTRACT
The isolation of lupeol, beta-sitosterol acetate and three quinolizidinic alkaloids, (+)-lupanine, (-)-sparteine and (-)-3 beta-hydroxy-13 alpha-tigloyloxy-lupanine (1), from the stem bark of Ormosia wayana is reported.
Subject(s)
Alkaloids/chemistry , Plants, Medicinal/chemistry , Quinolizines/chemistry , Rosales , Triterpenes/chemistry , Humans , Plant StemsABSTRACT
Centrifugal partition chromatography in the ion-exchange displacement mode allowed a preparative and efficient fractionation of low-molecular-mass heparins from enoxaparin sodium. Amberlite LA2--a lipophilic liquid secondary amine--was chosen as a weak anion exchanger. The biphasic system methyl isobutyl ketone-water was selected. Protonated LA2 (10%, v/v) was added to the organic stationary phase. Hydroxide (Na+, OH-) was chosen as a displacer in the aqueous mobile phase. The observed pH and concentration profiles are typical of displacement chromatography, as supported by numerical simulation. The Dubois test for the analysis of sugar content and an analysis of sulfur content (and consequently sulfatation rate) were carried out to monitor the effectiveness of the procedure. Moreover, the fractions were analyzed by high-performance size-exclusion chromatography and the 1H NMR spectra confirmed the fractionation of the sample of enoxaparin sodium.
Subject(s)
Chromatography, Ion Exchange/methods , Heparin, Low-Molecular-Weight/isolation & purification , Chromatography, Gel/methods , Chromatography, High Pressure Liquid/methods , Hydrogen-Ion Concentration , Magnetic Resonance Spectroscopy , Molecular WeightABSTRACT
Centrifugal partition chromatography (CPC) in the pH-zone refining mode allowed a preparative and efficient isolation of vindoline, vindolinine, catharanthine and vincaleukoblastine from a crude mixture of Catharanthus roseus alkaloids. The separation protocol was tested with a synthetic mixture of vindoline, catharanthine and vincaleukoblastine. The fraction content was analyzed and the results compared with theoretical chromatograms obtained by numerical simulation. The increase in injected sample mass results in an improvement of the purity of the isolated compounds. This observation, confirmed by theory, is of prime importance for the development of preparative pH-zone refining CPC as a preparative separation method.
Subject(s)
Chromatography/methods , Indoles/isolation & purification , Vinca Alkaloids/isolation & purification , Hydrogen-Ion ConcentrationABSTRACT
Four dammarane-type saponins were isolated by means of centrifugal partition chromatography from the root bark of Zizyphus lotus. Their structures were elucidated using a combination of 1D and 2D 1H and 13C NMR spectra and mass spectroscopy. One of these glycosides is the known jujuboside A. The others are three new dammarane saponins, identified as 3-O-beta-D-glucopyranosyl(1-->6)-beta-D-glucopyranosyl (1-->3)-[alpha-L-rhamnopyranosyl(1-->2)]-alpha-L-arabinopyranosyl jujubogenin = jujuboside C, 3-O-alpha-L-rhamnopyranosyl (1-->2)-[beta-D-glucopyranosyl(1-->3)]-beta-D-galactopyranosyl lotogenin = lotoside I, and 3-O-alpha-L-rhamnopyranosyl(1-->2)-[beta-D-glucopyranosyl (1-->3)]-beta-D-glucopyranosyl lotogenin = lotoside II. Lotogenin is a new dammarane derivative identified as (15R, 16R, 20R, 22R)-16 beta, 22-epoxydammar-24-ene-3 beta, 15 alpha, 16 alpha, 20 beta-tetraol.
Subject(s)
Plants, Medicinal/chemistry , Steroids/isolation & purification , Triterpenes , Carbohydrate Sequence , Magnetic Resonance Spectroscopy , Molecular Sequence Data , Plant Roots/chemistry , Spectrometry, Mass, Fast Atom Bombardment , Steroids/chemistry , DammaranesABSTRACT
Two Bolivian Aspidosperma species were investigated. The seed and stem bark of Aspidosperma macrocarpon Mart. contain six known alkaloids: (-)-vincadifformine, ervinceine, kopsanone, kopsinine, kopsanol in the seed, and kopsanone, kopsinine, kopsanol, 18-epikopsanol in the stem bark. The stem bark of Aspidosperma pyrifolium Mart. contains eleven known alkaloids: (-)-vincadifformine, O-demethylpalosine, haplocine, N-formylaspidospermidine, vallesine, demethoxyaspidospermine, palosine, (-)-aspidospermine, aspidospermidine, akuammicine, tubotaiwine, beside the two new bases dehydroxyhaplocidine and 10-methoxyaspidospermidine.
