Nonpolar lipid composition of Chenopodium album grown in continuously cultivated and nondisturbed soils.

Chenopodium album L. plants grown in continuously cultivated and in nondisturbed soils were compared in terms of the compositions of nonpolar extracts of the corresponding aerial parts. Both light petroleum ether extracts of C. album L. were analyzed by high-performance thin-layer LC, capillary GC, and capillary GC-EI-MS. Further percolation and medium-pressure LC, along with EI-MS analysis, permitted the separation and identification of the chemical constituents. Differences were observed between mean contents of the chemical constituents of C. album L., with respect to nonpolar extracts, obtained from continuously cultivated and from nondisturbed soils, in particular in linear and branched long-chain hydrocarbons, FA and their esters, and long-chain linear alcohols and aldehydes. The most remarkable features of the disturbed soils were a pronounced increase in the amounts of linear hydrocarbons and a decrease in the relative proportions of FA.

ent-Kaur-16-en-19-oic acid, a KB cells cytotoxic diterpenoid from Elaeoselinum foetidum.

Toxic and cytotoxic activities of the toxic plant Elaeoselinum foetidum (Apiaceae) were evaluated using the brine shrimp toxicity (BST) and KB cell cytotoxicity assays. The active chloroform extract was subjected to a bioactivity-directed fractionation, monitored by the BST assay, that led to the isolation of the diterpenoid ent-kaur-16-en-19-oic acid. This compound was potent against the brine shrimp (LC(50) = 4.8 microg/mL) and KB cells (IC(50) = 1.6 microg/mL).

Ayahoasca: an experimental psychosis that mirrors the transmethylation hypothesis of schizophrenia.

The experimental psychosis observed after drinking Ayahoasca, a South American hallucinogenic beverage from the Amazon Indians, reproduces the pathologic transmethylation theory of schizophrenia. This theory postulates a decrease in the monoamine oxidase (MAO) activity, which results in the accumulation of methylated indolealkylamines, such as bufotenin (5-hydroxy-N,N-dimethyltryptamine), N,N-dimethyltryptamine (DMT) and 5-methoxy-N,N-dimethyltryptamine. These substances are strong hallucinogens as has been previously confirmed experimentally. On the other hand, it is known that Ayahoasca is a beverage usually prepared by boiling two plants, one of them rich in beta-carbolines, which are naturally occurring strong inhibitors of MAO, and the other with high quantities of DMT. This particular combination reproduces what is supposed to occur under pathologic conditions of different psychoses. The effects of Ayahoasca were studied in subjects, assessing urine levels of DMT by gas chromatography-mass spectrometry (GC-MS) before and after the intake of the beverage. The results of this study confirm that the hallucinogenic compounds detected in the healthy subjects' (post-Hoasca, but not before) urine samples are the same as those found in samples from acute psychotic unmedicated patients. The chemical composition of the Ayahoasca beverage, and of the plant material used for its preparation are also reported as well as psychometric and neuroendocrine subject parameters.

Alkaloids from endophyte-infected Festuca argentina.

Five loline-type alkaloids, the known lolinine, N-formylloline, loline, N-methylloline and the new 5,6-dehydro-N-acetylloline, were characterized from the pooid-grass endophyte-infected Festuca argentina. These compounds are not responsible for the toxicity of the plant, as shown upon i.p. injection into mice. Their probable phytoalexine role and chemotaxonomical significance are discussed.

Linear, steroidal, and triterpene esters, and steryl glycosides from Festuca argentina.

Ester waxes and steryl glycosides of the grass Festuca argentina were studied. Saponification of the waxes from the petroleum ether extract led to n-hexacosanol as the major single linear alcohol, along with pentacyclic triterpenols, such as beta-amyrin, germanicol, isobaurenol, lupeol, hopenol-a and hopeol, and low amounts of sterols, such as cholesterol, campesterol, stigmasterol, sitosterol and dihydrositosterol, identified by gas chromatography/mass spectrometry (GC/MS). Fatty acids were identified as methyl esters as C12:0, C14:0, C16:0, C18:0, C18:2, and C20:0. The occurrence of a wide chainlength range of fatty acids and a single linear alcohol closely matched for other reports on the tribe Festuceae. On the contrary, pentacyclic triterpenols with a variety of skeletons, especially isobauerenol, are not usual as esters of fatty acids in the Gramineae. Low amounts of steryl glycosides were also obtained from the methylene chloride percolate of the methanol extract. Upon acetylation followed by hydrolysis, aglycones were identified by capillary gas-liquid chromatography (GLC) and GC/MS. As delta 7-cholesterol, campesterol, stigmasterol, sitosterol, dihydrositosterol, and the sugars as glucose, xylose, and arabinose by GLC of the respective alditol acetates. This is the first report on the linear, steryl, and triterpenyl esters of F. argentina. It is noteworthy that delta 7-steryl glycosides are rare, and steryl monoarabinosides have not been previously reported on the family Gramineae.

Alkaloids of Datura ferox from Argentina.

Chromatographic procedures (HPLC, GC-MS) are outlined in this paper for the analysis of alkaloids in poisonous Datura ferox seeds of Argentina, from which previously only quantitative analysis for scopolamine was known. Five additional tropane alkaloids are now identified as 3 alpha-tigloyloxytropane (tigloyltropeine), 3-phenylacetoxy-6 beta,7 beta-epoxytropane (3-phenylacetoxyscopine), aposcopolamine (apohyoscine), 7 beta-hydroxy-6 beta-propenyloxy-3 alpha-tropoyloxytropane, traces of 7 beta-hydroxy-6 beta-isovaleroyloxy-3 alpha-tigloyloxytropane and a pyrrolidine alkaloid, hygrine. Two new structures, 3-phenylacetoxy-6 beta,7 beta-epoxytropane (3-phenylacetoxyscopine) and 7 beta-hydroxy-6 beta-propenyloxy-3 alpha-tropolyoxytropane, are proposed on the basis of their spectra. Hyoscyamine, nicotine and tropane N-oxides were not detected in all samples studied.

Evolution of flavonoids in the Phaseolinae.

Twenty South American Phaseolinae species were screened for flavonoids including eight species of Vigna: V. luteola, V. adenantha, V. candida, V. longifolia, V. lasiocarpa, V. caracalla, V. hookeri and V. peduncularis; three Phaseolus species: P. vulgaris var. aborigineus, P. lunatus and P. augustii; eight Macroptilium species: M. fraternum, M. psammodes, M. prostratum, M. panduratum, M. longepedunculatum, M. bracteatum, M. erythroloma and M. lathyroides and Dolichopsis paraguariensis were examined. The majority of the isolated compounds (70%) were flavonol O-glycosides, mainly of quercetin (40%) and kaempferol (24%). Only one myricetin glycoside was detected with the more primitive trihydroxylated B-ring. The chemical profiles of these Phaseolinae species correspond to an intermediate evolutionary level according to the parameters of Harborne and appear to be relatively advanced in relation to the other members of the subfamily Papilionoideae.

Antitumor and cytotoxic screen of 5,6,7-trisubstituted flavones from Gomphrena martiana.

An in vivo antitumor screening of extracts of Gomphrena martiana indicated positive activity in the petroleum ether extract, and its further bioactivity-directed fractionation resulted in a lipophilic flavonoid fraction. Upon inoculation of various doses of 5,6,7-trisubstituted flavones on two murine tumor lines, Sarcoma 180 and Ehrlich's carcinoma, a decrease of tumor growth was observed. An in vitro KB cultured cell screen indicated cytotoxicity.

Antimicrobial constituents of Gomphrena martiana and Gomphrena boliviana.

The antimicrobial activity of extracts and constituents of Gomphrena martiana and Gomphrena boliviana (Amaranthaceae) were determined in order to identify the compounds responsible for the folk-medicinal use of these plants. Each extract was evaluated against 20 microorganisms, including Gram-positive and Gram-negative bacteria, spore-forming Gram-positive bacteria, an acid-fast bacterium, a fungus and two yeasts. Fractionation of each petroleum ether (PE) extract yielded five 5,6,7-trisubstituted flavones that were separately tested showing high activity against M. phlei (minimum inhibitory concentration (MIC) 15, 20 and 75 micrograms/ml) approaching that of commercial bactericides. Other natural and synthetic flavonoids with diverse structures were also tested to define structure-activity relationships. Each EtOH extract was subsequently fractionated and monitored by bioassays leading to isorhamnetin 3-O-beta-robinobioside (MIC 50 micrograms/ml) in both instances. This glycoside is reported here for the first time in G. boliviana.

The lethal principle of Poa huecu (coiron blanco): a plant indigenous to Argentina.

The lethality of Poa huecu, a plant toxic to cattle and sheep, was followed by injection of chromatographic fractions in mice. The lethal aqueous extract was administered i.p. to Rockland mice of either sex and produced motor incoordination, transient ataxia, rough hair coat, tremors and muscle contractions and, occasionally, blindness. Doses greater than 1.5 g/kg mouse were always lethal. Fractionation of this lethal extract included dialysis, column chromatography on Sephadex G-25 and fractional precipitation with ethanol. Precipitates obtained with 70% and 85% ethanol were further purified on a DEAE-cellulose column. Eight fractions were obtained, each was injected into mice. Only fractions 3-6 were toxic. Fraction 3 produced slight hepatosis and hyperemia in the liver and gliosis in the brain. None of the other tissues exhibited histological lesions. Fractions 4 and 5 caused death of all animals within 30 min to 4 hr after injection. Polyacrylamide gel electrophoresis and acid hydrolysis showed that fractions 4 and 5 contained a glycoprotein of nearly the same mol. wt (67,000-94,000). Microscopic pathology in the mice treated with the lethal glycoprotein of fraction 4 included hyperemia in the kidneys, megakaryocytes in the spleen, slight hepatosis and focal coagulative necrosis with nuclear pyknosis and karyonexis in the liver, gliosis, intracellular brain edema with axon degeneration and swollen astrocytes in the brain. These brain injuries may relate to the motor incoordination of cattle that causes a delayed righting reflex. The major monosaccharides of the lethal glycoprotein are glucose and mannose, while rhamnose, arabinose, xylose and galactose are present in low percentages. Proline and the acidic amino acids (glutamic and aspartic acids) are the most abundant in the peptidic residue.