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A novel molluscicide against Pomacea canaliculata snails (Golden apple snail, GAS) based on quinoa saponins (Chenopodium quinoa) is presented. Quinoa is a pseudocereal extensively cultivated and consumed in Bolivia and Peru. The external husk of the grains is removed prior to human consumption due to the bitter taste imparted by their high saponin content (predominantly bidesmosidic saponins), and constitutes a by-product with no commercial value. When tested against GAS, quinoa husks showed no activity up to 121 ppm product (approximately 35 ppm saponins). To increase their molluscicidal properties, the husks were treated with alkali to convert bidesmosidic saponins to more active monodesmosides. This product killed 100% GAS under laboratory conditions at 24 h at approximately 33 ppm product. Surprisingly no toxicity to fish, such as goldfish or tilapia, was observed up to the highest concentration tested (e.g., 54 ppm product). This is a main advantage in relation to available commercial molluscicides that kill fish at product doses lower than those that kill GAS (e.g., niclosamide). The product was also tested preliminary under field conditions in Northern Argentina with similar GAS mortality results. A preliminary LC/ESI–MS/MS study revealed that the husks contained a mixture of known and novel bidesmosidic and monodesmosidic saponins. However, the alkali treated husks did not contain monodesmosidic saponins as expected, but large molecular weight saponin derivatives, probably formed between the saponins and other compounds present in the quinoa hulls under alkaline conditions. Due to the complex nature of these compounds, no direct relationship could be established between product efficacy and a higher content of monodesmosidic saponins. The results suggested that the molluscicidal properties are probably related to the formation of more hydrophobic compounds after alkaline treatment that have higher affinity with the cholesterol present in GAS gills.

Acetylcholinesterase inhibitors (AChEI) are currently still the best available pharmacotherapy for Alzheimer patients. Successful screening for new AChEI relies on effective and fast assays. Two colorimetric screening assays frequently used to search for new AChEI, namely a thin layer chromatography (TLC) assay with Fast Blue B salt as reagent and a 96-well plate assay based on Ellman's method, were compared. For the majority (83%) of the 138 test compounds of natural and synthetic origin, the results obtained with the two assays converged and both screening assays were considered suitable for the generation of new hits. Fifteen percent of investigated compounds were classified as active with the microplate assay but were shown to be inactive by TLC and about 2% were measured active by TLC but showed to be inactive with the microplate assay. These divergences were not due to the main differences between the experimental protocols of the two screening assays, namely the different colorimetric methods and pre-incubation of test compounds with acetylcholinesterase (AChE). They might be explained by the interaction of either AChE or test compounds with the silica of the TLC plates, resulting in an altered affinity of the enzyme for the compounds.

In order to find some medicinal value for invasive neophytes, inhibition of acetylcholinesterase of Reynoutria sachalinensis F. Schmidt ex Maxim. (Polygonaceae), Polygonum cuspidatum Siebold. Zucc. (Polygonaceae), Heracleum mantegazzianum Sommier Levier (Apiaceae), Buddleja davidii Franch. (Buddlejaceae), and Ambrosia artemisiifolia L. (Asteraceae) was prescreened by a bioautographic TLC assay. Activity was found in the methanol extract of the leaves of the common ornamental bush B. davidii. Its fractionation by centrifugal partition chromatography led to the isolation of linarin as the most active compound. While extracts of Buddleja nitida Benth. (Buddlejaceae) from Panama were inactive, some constituents were identified on the basis of a comparison with B. davidii by HPLC-MS/MS. Structure-activity relationships of linarin and related flavonoids were investigated. For this purpose, fortunellin and tilianin were prepared by methylation reactions. It appears that the structural elements important for acetylcholinesterase inhibition are not only the 4' -OMe group, but also the 7-substituted sugar and the pattern of substitution on the B-ring.

Over the last 10 years, numerous cases of intoxications, leading for the most part to end-stage renal failure, have been reported after consumption of slimming regimens made of Chinese herbal preparations. These intoxications were associated with species of the Aristolochia genus, such as Aristolochiafangchi (Aristolochiaceae), known to contain very nephrotoxic and carcinogenic metabolites named aristolochic acids. Several commercial dietary supplements, teas and phytomedicines used as slimming regimens were analysed for their aristolochic acid I content. A preliminary detection of this toxic compound was made by thin-layer chromatography. The presence of aristolochic acid I in these preparations was confirmed by a HPLC/UV-DAD/MS analysis. A quantitative determination of aristolochic acid I was also achieved in the incriminated preparations using both UV and MS detection. Out of 42 analysed preparations, four were found to contain aristolochic acid I and two were suspected to contain aristolochic acid derivatives. Immediate removal of these products from the Swiss market was called for. (C) 2003 Elsevier Science Ltd. All rights reserved.

Polygonum cuspidatum Sieb. and Zucc. has been traditionally used as a member of many anti-inflammatory polyherbal formulations, but is now a widespread invasive neophyte in Europe and America. To discuss if the invasive variety is chemically identical to the native one in traditional medicine, the different constituents of the invasive variety compared to the native variety were isolated and their anti-inflammatory activity was tested. Resveratroloside and catechin-(4α→8)-catechin, the newly found constituents in the invasive variety, have similar nitric oxide (NO) inhibition potency as that of piceid (the major constituent of P. cuspidatum), but the newly found major constituent, i.e., piceatannol glucoside, showed no apparent effect. On the other hand, as a marker, the total content of resveratrol in the methanol root extract after glucosidase hydrolysis was measured and compared between the invasive and native varieties. The total content of resveratrol measured in the root extracts of the Swiss sample was about 2.5 times less than that of the Chinese one. This study brings attention to the point that when the invasive variety of P. cuspidatum is used in traditional medicine, the chemical difference should be kept in mind.

Plants of the genus Garcinia (Clusiaceae) are traditionally used to relieve stomachaches, toothaches, and as a chew stick.In order to determine which compounds were responsible for these activities, a phytochemical investigation of the fruits and leaves of Garcinia preussii Engl. was pursued.Plants were extracted by solvents of various polarities. Compounds isolation was then carried out using chromatography methods (medium- and high-pressure liquid chromatography, open column and thin-layer chromatography). The isolated compounds were identified and characterized by using 1D and 2D NMR spectroscopies. The antioxidant activity was evaluated using DPPH(•), ABTS(•-), ALP, and ORAC assays. The antimicrobial activity was assayed against Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, and Enterococcus faecalis by determining the minimum inhibitory concentration (MIC) value. The cytotoxic activity of most of the isolated compounds was evaluated on a small panel of human cancer cell lines (DU145, HeLa, HT-29, and A431) using the XTT method.The phytochemical investigation of G. preussii led to the isolation of eight known compounds, six benzophenones and two flavonoids. These compounds were tested for their biological activities. 1, 2, 3, 4, 7 and 8 demonstrated a high free radical scavenging activity with ER50 ranging from 0.1 to 0.7. The antimicrobial activity was shown only against Gram-positive bacteria for 1, 4, and 5. A moderate cytotoxic activity with IC50 ranging from 7 to 50 µM was observed, except for 6 which was not active.These results appear to support some of the properties reported for Garcinia species.

The terpenoid constituents of Targionia lorbeeriana grown in vivo and in vitro were com pared. The analysis of the dichloromethane extract was performed by HPLC-UV and by HPLC-M S. The obtained results revealed that the sesquiterpene lactones isolated from the dichloromethane extract of the wild Targionia lorbeeriana were also produced by the liverwort in in vitro cultures, in the same relative amounts. The composition of essential oils was evaluated by GC and GC-MS. Both, the yield and diversity of the essential oil obtained from wild growing T. lorbeeriana gametophytes were higher than those growing in vitro. Although, a significant number of compounds produced in vivo were maintained in vitro, a considerable number of other ones were not detected. Instead, under in vitro conditions, some new compounds were found which do not accumulate under wild conditions.

For many social and environmental reasons, over the last few decades, there has been an increase in chronic and life-threatening diseases including mycoses, hyperuricemia-related disorders and some mental illnesses such as depression, anxiety and Parkinson's disease. In order to fight these diseases, compounds acting on various biological targets, including enzymes such as xanthine oxidase or monoamine oxidase, have to be screened. The enzyme xanthine oxidase catalyses the oxidation of hypoxanthine to xanthine and then to uric acid, which plays a crucial role in hyperuricemiarelated disorders such as gout and renal stones. One of the therapeutic approaches to treat these diseases is the use of xanthine oxidase inhibitors that block the production of uric acid. Monoamine oxidases (E.C.1.4.3.4) A and B catalyse the oxidative deamination of monoamines in the central nervous system and peripheral tissues. Inhibitors of MAO A are clinically useful to treat anxiety and depression since they are expected to increase both noradrenalin and serotonin levels in the brain. On the other hand, inhibition of MAO B appears to be an effective approach for the prevention and adjunct treatment of Parkinson's disease. In traditional Chinese medical practice, many medicinal herbs have been used to treat chronic diseases such as fungal infections, hyperuricemia-based disorders and mental illnesses. This usage is indicative for the presumable presence of antifungal phytochemicals and inhibitors of xanthine and monoamine oxidases. Plants do not represent the only source for interesting natural products; some endophytes ('special' microorganisms living inside the healthy host plant) are also known to produce secondary metabolites of promising pharmaceutical and/or agricultural potential. The above observations prompted us to search for natural antifungal compounds and inhibitors of xanthine and monoamine oxidases in different Chinese plants and endophyte cultures. The active constituents isolated were mainly mono-, sesqui-, di-, and triterpenes, sterols, coumarins, flavonoids, phenylethanoids, stilbenoids, alkaloids and alcohols.

Rapid detection of biologically active natural products plays a key role in the phytochemical investigation of crude plant extracts. In order to perform an efficient screening of the extracts, both biological assays and HPLC analysis with various detection methods are used. Techniques such as HPLC coupled to UV photodiode array detection (LC/DAD-UV) and to mass spectrometry (LC/MS or LC/MS/MS) provide numerous on-line structural data on the metabolites prior to isolation. The recent introduction of HPLC coupled to nuclear magnetic resonance (LC/NMR) represents a powerful complement to LC/UV/MS screening. Various plant species belonging to the Gentianaceae and Leguminosae have been analysed by LC/UV, LC/MS, LC/MS/MS and LC/NMR. These hyphenated techniques allow a rapid structural determination of known plant constituents with only a minute amount of plant material. Simple bioautographic assays such as those used for screening antifungal constituents can also be performed on-line directly by collecting HPLC peaks and measuring the activity against the fungi of interest. These bioassays permit a rapid localisation of the bioactive natural products. With such a combined approach, the time consuming isolation of common natural products is avoided and an efficient targeted isolation of compounds presenting interesting spectroscopical or biological features is performed. Several representative applications of the use of LC/MS and LC/NMR for the dereplication and identification of antifungal constituents are presented in the present paper.

Three new sesquiterpene lactones (acetyltrifloculoside, 8,15- acetylsalonitenolide and 8-acetylsalonitenolide) and two known sesquiterpene lactones were isolated from a dichloromethane extract of the Portuguese liverwort Targionia lorbeeriana. Their structures were established by spectroscopic methods (EI and D/CI mass spectroscopy, 1H and 13C NMR) and that of acetyltrifloculoside was confirmed by X-ray crystallography. The three isolated guaianolide sesquiterpene lactones presented antifungal activity against Cladosporium cucumerinum and larvicidal activity against Aedes aegypti. Only one of the isolated lactones presented activity against Candida albicans.

A total of 204 crude extracts of Indonesian plants (77 species from 43 families) have been screened for their fungicidal (Cladosporium cucumerinum, Candida albicans) and free radical scavenging [2,2-diphenyl-1-picrylhydrazyl (DPPH) radical] activities. Of the species investigated, 20 were active against Cladosporium cucumerinum, nine against Candida albicans and 24 exhibited radical scavenging properties.

Three antifungal xanthones have been isolated from the dichloromethane root extract of Marila laxiflora (Guttiferae). Their structures were established by spectrometric (UV, EI mass spectrometry, 1 H and 13 C nmr) and chemical methods. In addition, other compounds were isolated from the methanol extract: a fourth xanthone, rhamnetin, betulinic acid, and a derivative of benzoic acid.

INTRODUCTIONLiverworts are known to be a rich source of terpenoidsand phenolic compounds which constitute the oil bodies.From these plants a high diversity of substances has beenisolated, including new structure types, some of themwith interesting biological activities (Asakawa, 1989).Since only a few species of liverworts have beenphytochemically investigated (less than 5% of knownspecies), many interesting substances remain to beisolated. However, advances on the study of thechemistry of these plants are hindered by the difficultyin collecting a sufficient quantity of pure material ofcertain species. Their small size and the fact thatliverworts usually grow mixed with other bryophytesand are strongly attached by their rhizoids to the soil,make their purification a difficult and time consumingtask (Becker and Harrison, 1987; Asakawa, 1989). Invitro cultures of liverworts can be a good alternative,producing sufficient and homogenous amounts of plantmaterial for subsequent analysis (One et al., 1992; Takaziet al., 1995).The genus Asterella contains approximately 80 species(Frahm and Frey, 1983) but only a few have been studiedphytochemically: Asterella augusta, A. odora; A. aus-tralis; A. tenera, A. lindenbergiana; A. venosa (Asakawaand Heidelberger, 1982). In this work, we report theisolation and structural elucidation of three hopane typetriterpenoids and one flavonoid, from in vitro cultures ofAsterella blumeana. The structures are shown in Figures1 and 2.MATERIAL AND METHODSPlant material and culture conditions. Plants of theliverwort Asterella blumeana (Nees) Pande´ Srivastava etKhen grown in vitro, obtained from the culture collectionof autotrophic organisms of the Institute of Botany,Trebon, Czech Republic, were subcultured on fresh B5medium (Gamborg et al., 1968) every 2 months andmaintained in a photoperiod of 16 h light (30 mol/m

Boophiline (1), a new sterol amide was isolated from the cattle tick Boophilus microplus (Ixodidae). The structure was assigned as N-[3-(sulfooxy)-25ξcholest-5-en-26-oyl]-L-isoleucine by detailed 2D NMR investigations in conjunction with FAB mass spectrometry and acidic hydrolyses. Complete assignment of the diastereotopic methylene protons of the ring system could be deduced from the NMR data. In agar dilution assays, 1 exhibited antifungal properties against Cladosporium cucumerinum and antibacterial activity against Bacillus subtilis and Escherichia coli.

Rapid detection of biologically active natural products plays a strategic role in the phytochemical investigation of crude plant extracts. In order to perform an efficient screening of the extracts, both biological assays and HPLC analysis with various detection methods are used. Combined techniques such as HPLC coupled to UV photodiode array detection (LC/UV) and to mass spectrometry (LC/MS or LC/MS/MS) provide useful structural information on the metabolites on-line prior to isolation. The recent introduction of HPLC coupled to nuclear magnetic resonance (LC/NMR) represents a powerful complement to the LC/UV/MS screening. Various plants belonging to the Gentianaceae and Leguminosae families have been analysed by LC/UV, LC/MS, LC/MS/MS, and LC/NMR. The use of all these coupled techniques allows the structural determination of known plant constituents rapidly and with only a minute amount of plant material. With such an approach, the time-consuming isolation of common natural products is avoided and an efficient targeted isolation of compounds presenting interesting chemical or biological features can be performed.

Seed husk extracts of Convolvulus tricolor L. (Convolvulaceae) afforded six compounds, identified for the first time from this plant: isorhamnetin 3-O-beta-D-galactopyranoside (1), isorhamnetin 3-O-beta-D-(6"-acetyl)-galactopyranoside (2), isorhamnetin 3-O-robinobioside (3), 3,4-di-O-caffeoylquinic acid (4), gentisic acid 5-O-glucoside (5), and scopoletin (6). Separation of compounds was carried out by CC and CPC. Structural elucidations were performed by HPLC-UV-DAD, HPLC-ESI/MS (negative mode) and NMR.

Chresta martii (Asteraceae) is a plant found in the Xingo region (semi-arid area) in Northeastearn Brazil, and is recognized by the local population as a traditional herb used to treat gastric diseases. This is the first report of the chemical composition, acute toxicity, and gastroprotective effect in mice of the hydroalcoholic extract (HAE) from the aerial parts (leaves and flowers) of Chresta martii. Animals received HAE doses from 10 to 2000 mg/kg, i.p. or 50 to 3000 mg/kg, p.o.) and were observed over 48 h for toxicity signs and mortality; sub-chronic toxicity was evaluated through 14 days treatment with once-daily HAE doses (400 mg/kg, p.o.). The gastroprotective effect of HAE was demonstrated on the indomethacin-induced gastric ulcer model after the administration of extracts. Data comparison of ulcer index averages between saline and HAE (100 or 400 mg/kg, p.o.) groups showed significant (P

A new flavanone-chromone biflavonoid, preussianone (1), has been isolated from the leaves of Garcinia preussii, along with four known biflavonoids. The absolute stereostructures were elucidated by chemical, spectroscopic, and chiroptical methods. The biological properties of the new biflavonoid against several bacterial strains were evaluated.

1. Previous studies have shown that extracts of feverfew (Tanacetum parthenium) and parthenolide, a sesquiterpene alpha-methylenebutyrolactone obtained from it, inhibit smooth muscle contractility in a time-dependent, non-specific and irreversible manner. 2. The hypothesis that this toxic effect is due specifically to the presence in the sesquiterpene lactone of the potentially reactive alpha-methylene function was tested on rabbit isolated aortic ring preparations. This was done (a) by comparing the effects of two plant-derived sesquiterpene lactones purified from yellow star thistle (Centaurea solstitialis): cynaropicrin (an alpha-methylenebutyrolactone) and solstitialin 13-acetate (lacking the alpha-methylene function), and (b) by chemically inactivating the alpha-methylene functions in cynaropicrin and parthenolide by reaction with cysteine. 3. The results show that the characteristic smooth muscle inhibitory profile is demonstrated by the two alpha-methylenebutyrolactones (parthenolide and cynaropicrin), but not by the compound lacking this functional group (solstitialin 13-acetate), or by those previously active compounds in which it has been inactivated with cysteine. 4. Thus the alpha-methylene function is critical for this aspect of the toxic pharmacological profile of the sesquiterpene butyrolactones, which are natural products widely distributed in the Compositae family of flowering plants.

The increasing occumnce of opportunistic systemic mycoses associated with the use of immunosuppressive drugs and AIDS has led to new efforts in the search for novel antifungal compounds. At the same time, there is continuing interest in the discovery of antifungal agents which are effective against plant pathogenic fungi. Since the plant kingdom provides a useful source of lead compounds of novel structure, a wide-scale investigation of species from the tropics has been undertaken. TLC bioautography allows the screening of plant material and subsequent bioassay-guided fractionation and isolation.

Stem and leaves infusion of Chuquiraga spinosa (RP) Don. (Asteraceae) is used in the Peruvian traditional medicine for its anti-inflammatory properties and for the treatment of vaginal infections.This study evaluated the antioxidant, anti-inflammatory and antifungal activities of C. spinosa for the first time.Extracts of methanol, 50% methanol and water were obtained from C. spinosa aerial parts. Antioxidant activity of the extracts was evaluated (DPPH˙, ABTS˙(+) and superoxide radical-scavenging activity). The correlation between these results and total polyphenolic content was determined by Pearson's Correlation Coefficient. Anti-inflammatory activity of 50% methanol extract was evaluated with the rat model of carrageenan-induced acute inflammation and mouse model of TPA-induced acute inflammation. The antifungal activity of the extracts against Cladosporium cucumerinum and Candida albicans was studied by direct bioautography, and antifungal activity against phytopathogenic fungi was performed by culture in potato dextrose agar plates.All the extracts showed high antioxidant activity, and there was correlation between the activity and total polyphenolic compounds. As 50% methanol extract was administered orally, the paw edema in rats was reduced significantly (52.5%). This extract, by topical administration, produced a reduction of 88.07% of the edema TPA-induced in ear of mice. The aqueous and 50% methanol extracts were active against C. albicans (minimum inhibitory concentration of 2.5 and 6.25 µg, respectively). The aqueous extract showed antifungal activity against C. cucumerinum (MIC: 2.5 µg).Preliminary phytochemical screening and the analysis of the three extracts by high-performance liquid chromatography diode-array detection showed the majority compounds are flavonoids and phenolic acid derivatives. These compounds may be responsible of the radical-scavenging activity of these extracts as well as responsible of anti-inflammatory effect in vivo of 50% methanol extract. Several authors have demonstrated the antioxidant and anti-inflammatory properties of some flavonoids and phenolic acids. The antifungal activity of the extracts obtained from aerial parts of C. spinosa has been investigated here for the first time. Other studies are necessary to determine the mechanism of action and to identify the bioactive compounds of this plant.

Thirteen compounds have been isolated from the methanol extract of Saxifraga cuneifolia L. (Saxifragaceae) whole plant. These were identified as five new compounds, (E)-5-O-beta-D-glucopyranosyl-stilbene-3,3', 4,5'-tetraol, (E)-4-O-beta-D-glucopyranosyl-5-methoxy- stilbene-3,3',5'-triol, 4-[ 4'-O-(6''-O-galloyl-beta-D-glucopyranosyl)- 3'-hydroxyphenyl] butan-2-one, 3-O( 6''-O-galloyl-beta-D-glucopyranosyl)-epigallocatechin and 3-O-beta-D-glucopyranosyl-epigallocatechin, together with the known compounds 4-[4'-O-beta-D-glucopyranosyl- 3'-hydroxyphenyl]-butan-2-one, (R) rhododendrin, 1-O-galloyl-beta-D-glucose, catechin, 3-O-galloyl-epigallocatechin, gallocatechin, clitorin and rutin, by chemical and spectroscopic methods. Their free radical scavenging properties are also described.

Two new tropane alkaloid N-oxides substituted by a methylpyrrole moiety were isolated from the bark of Erythroxylum vacciniifolium Mart. (Erythroxylaceae), a Brazilian indigenous plant, locally known as catuaba and used in traditional medicine as an aphrodisiac. The alkaloid structures were determined by a combination of high resolution mass spectrometry and multi-dimensional NMR spectroscopy.

Scleria striatonux (Cyperaceae), a spice traditionally used in Cameroon, displayed an antiplasmodial activity. Two new sesquiterpenes, 1 (sclerienone A) and 2 (sclerienone B), have subsequently been isolated from the methylene chloride/methanol extract of the rhizome. Their separation involved a combination of methods including repeated silica gel open column chromatography, Sephadex LH-20 and semi-preparative HPLC. Structure elucidation was achieved by means of chemical tests and extensive spectral studies.

Higher plants represent a rich source of new molecules with pharmacological properties, which are lead compounds for the development of new drugs. During the last decades, the renewed interest in investigating natural products has led to the introduction of several important drugs, such as the anticancer drugs vinblastine and taxol, or the antimalarial agent artemisinin. Success in natural products research is conditioned by careful plant selection, based on various criteria such as chemotaxonomic data, information from traditional medicine, field observation, or even random collection. One main strategy in the isolation of new lead compounds consists of so-called bioactivity-guided isolation, in which pharmacological or biological assays are used to target the isolation of bioactive compounds. One major drawback of this strategy is the frequent isolation of known metabolites. Therefore, metabolite profiling using hyphenated techniques such as LC/UV, LC/MS and more recently LC/NMR rapidly provides plenty of structural information, leading to a partial or a complete on-line de novo structure determination of the natural products of interest. The combination of metabolite profiling and LC/bioassays gives the possibility to distinguish between already known bioactive compounds and new molecules directly in crude plant extracts (dereplication). Thus, the tedious isolation of compounds of low interest can be avoided and a targeted isolation of new bioactive products. Some examples of rapid localization of bioactive compounds, based on post-chromatographic bioautographic testing of LC/NMR microfractions and subsequent on-line identification will be illustrated in this review. Possibilities and limitations of LC/UV/NMR/MS and LC/bioassay as well as future developments expected in this field will be discussed.

Este trabalho apresenta a identificacao “on line” de flavonas minoritarias do suco da cana-deacucar (Saccharum officinarum) , por cromatografia liquida de alta eficiencia com detector UV acoplada a espectrometria de massas (CL/UV/EM) com ionizacao quimica a pressao atmosferica, dissociacao induzida por colisao (IQPA-DIC-EM/EM) e derivatizacao pos-coluna utilizando reagentes de deslocamento de UV. As analises CLAE-UV com reagentes de deslocamento forneceram informacoes sobre a posicao da substituicao no esqueleto dos flavonoides e, em combinacao com dados de EM, estas tecnicas permitiram a identificacao “on-line” de cinco flavonas da garapa: luteolina-8- C-glucosil-7-O-glucuronideo; tricina-7-O-neoesperosideo-4’O-ramnosideo; tricina-7-O-metilglucuronato-4’-O-ramnosideo; tricina-7-O-metilglucuronideo; swertisina; e outras quatro substâncias foram parcialmente identificadas como flavonas glicosiladas. Somente a swertisina (7-O-metilapigenina-6-C-glicosideo) foi anteriormente descrita no bagaco da cana-de-acucar. This work describes the on-line characterization of minor flavones from sugarcane (Saccharum officinarum ) juice by high-performance liquid chromatography coupled to diode array UV detection and mass spectrometry (LC/UV/MS) using atmospheric pressure chemical ionizationcollision-induced dissociation (APCI-CID-MS/MS) and post-column derivatization using UV shift reagents. HPLC-UV analysis with shift reagents provided information about the substitution pattern in the flavonoid skeleton and, combined with MS data, these techniques allowed for the on-line identification of five “garapa” flavones: luteolin-8- C-glucosyl-7-O-glucuronide; tricin-7-O-neohesperoside-4’-O-rhamnoside; tricin-7-O-methylglucuronate-4’-O-rhamnoside; tricin-7-O-methylglucuronide; swertisin, while four other compounds were partially identified as glycosylflavones. Only swertisin (7- O-methylapigenin-6-C-glucoside) was reported previously in sugarcane molasses.

Three iridoid glucosides, two phenylpropanoid derivatives and one flavonoid have been isolated from the methanolic whole plant extract of Bartsia alpina L. (Scrophulariaceae). Their structures were established by spectrometric (UV, D/CI and FAB mass spectrometry, 1 H and 13 C NMR) and chemical methods. Some of these compounds have radical scavenging activity against DPPH or antioxidant activity against s-carotene on TLC bioassay.

The dicholoromethane extract of Pseudocedrela kotschyi root demonstrated marked antileishmanial properties in preliminary screening of extracts from 21 species commonly used in Malian traditional medicine. Phytochemical investigation of the active extract yielded three novel phragmalin-type limonoid orthoacetates (1-3), named kotschyins A-C, and the known compounds 7-deacetylgedunin (4) and 7-deacetyl-7-oxogedunin (5). The structures of 1-3 were elucidated by analytical methods including 1D- and 2D-NMR spectroscopy together with MS spectroscopy. The relative configurations of 1-3 were assigned on the basis of NOE correlations. The extract and the isolated compounds were tested for their antiprotozoal activities against Leishmania donovani, Trypanosoma brucei rhodesiense, Trypanosoma cruzi, and Plasmodium falciparum as well as for cytotoxicity toward the L-6 cell line. The crude extract and the two gedunin derivatives exhibited good in vitro activity against all of these parasites.

Este trabalho apresenta a primeira investigacao sobre a estrutura quimica dos flavonois presentes em cascas das tres variedades de macas mais cultivadas no Brasil: Gala, Golden e Fuji. As analises foram feitas por CL/UV/EM (cromatografia liquida de alta eficiencia com detector UV com arranjo de diodos acoplada a espectrometria de massas), usando adicao poscoluna de reagentes de deslocamento de UV e tambem espectrometria de massas de multiplos estagios (EM n ) com ionizacao “electrospray” no modo negativo. A identificacao “on-line” com base nos dados de CL/UV/EM demonstrou a presenca de rutina, hiperosideo, isoquercitrina, quercitrina e outros tres derivados de quercetina-3-O-pentosideo. As analises por CL/UV/EM tambem demonstraram que as tres variedades de maca tem perfis cromatograficos semelhantes. This work describes the first detailed investigation into the chemical structures of flavonols present in the three apple varieties most commonly cultivated in Brazil: Gala, Golden and Fuji. The analyses were carried out by LC/UV/MS (high-performance liquid chromatography coupled to diode array UV detection and mass spectrometry), using post-column addition of UV shift reagents, as well as multiple stage mass spectrometry (MS n ) with electrospray ionization in the negative ion mode. Rutin, hyperoside, isoquercitrin, quercitrin, quercetin and three other quercetin-3-pentoside derivatives were identified through the characterization of on-line-based LC/UV/MS data. LC/UV/MS analysis also revealed that the three apple cultivars have similar chromatographic profiles.

The alkaloid profile of the aerial parts of Schizanthus tricolor Grau et Gronbach was investigated by GC-MS. Seventeen alkaloids were detected and are reported in this species for the first time. They were identified by means of retention indices, together with the fragmentation pattern of reference material. 3α-Methylitaconyloxytropane (12) is identified as a new alkaloid.

Plant Molecular Biology, 65 (5), ISSN:0167-4412, ISSN:1573-5028

Plants have a rich history as medicines for human use. Recently introduced plant-derived drugs include paclitaxel from Taxus (Taxaceae) species for the treatment of cancers, artemisinin for malaria therapy and the alkaloid galanthamine for the management of Alzheimer's disease. A judicious combination of chemical and biological screening techniques can provide a steady supply of lead compounds for the improved treatment of human ailments. By this means, candidate compounds can be rapidly selected for further development, as is the case for xanthones from gentians and coumarins from Peucedanum ostruthium (Apiaceae), which may be of relevance in Alzheimer's disease. Encouraging results are also being obtained for hypericin from Hypericum perforatum (Hypericaceae) in the photodynamic therapy of cancer. An aspect that must not be forgotten is that the usual biological screening procedures do not pick up prodrugs which have to be metabolized by the human body into active analogues. A good example is salicin from Salix species (Salicaceae) which is metabolized in the body to give the anti-inflammatory and analgesic compound salicylic acid. Investigations which include simulation of metabolism are thus of primordial importance.

Chemical investigation of plant constituents is strongly linked to the use of liquid chromatography (LC) at both the analytical and preparative level. Indeed, most of the secondary metabolites can be efficiently separated or isolated by different liquid chromatographic techniques. The plant extracts are generally screened by different bioassays and submitted to fractionation by chromatography. The fractions obtained are further tested for their biological activities. This process is repeated until the isolation of a pure active constituent, which is finally identified by spectroscopic methods (bioactivity guided isolation.

Randia siamensis is used in Thai folkloric medicine for inducing abortion and controlling blood pressure. The present study investigated the cardiovascular effects of an R. siamensis fruit extract, and mechanisms involved in anesthetized normal and reserpinized rats. R. siamensis (0.4-12 mg/kg) i.v. increased the mean arterial pressure (MAP) and heart rate. Both effects were significantly inhibited by phentolamine (2 mg/kg, i.v.) or propranolol (0.6 mg/kg, i.v.). The combination of phentolamine and propranolol, or reserpine pretreatment, inhibited the positive chronotropic effect with a slight decrease in the MAP. In vitro, R. siamensis (0.001-0.3 mg/ml) increased the rate of beating of the right atrium and the strength of the electrical field-stimulated contraction of the left atrium, both effects were inhibited by propranolol, or with reserpine pretreated rats. R. siamensis (0.01-3 mg/ml) produced a contraction of isolated thoracic aorta, which was potentiated by N-G-nitro-L-arginine (LNA), or by removal of the vascular endothelium, but inhibited by phentolamine, or reserpine. R. siamensis (0.3-3 mg/ml) caused a relaxation of phenylephrine-preconstricted aortic rings, which was potentiated with reserpine pretreatment, and abolished after removal of the vascular endothelium, or in the presence of LNA. These results suggest that R. siamensis extract exerts both hypertensive and positive chronotropic effects via the alpha-- and beta-adrenergic receptors of blood vessels and the heart, due to release of endogenous catecholamines, likely from nerve ending and adrenal medulla. The hypotensive activity results from the release of nitric oxide causing dilatation of the blood vessels. The present data support the folkloric therapeutic uses of this plant.

In the course of a study of medicinal plants from Mali, the root bark of Zanthoxylum zanthoxyloides Lam. (Rutaceae) was investigated. The root bark of this plant is used as a toothbrush by West African people. Phytochemical investigation of the MeOH extract of Zanthoxylum zanthoxyloides Lam. (Rutaceae) led to the isolation of different biologically active compounds. The separation of acetylcholinesterase inhibitors was performed by centrifugal partition chromatography (CPC). The fractions were monitored by direct TLC bioautographic assays. The bio-guided isolation led to the isolation of a new peroxide derivative. In addition, LC/UV/MS analysis performed on the crude MeOH extract allowed on-line identification of some known compounds. The structures of the isolated compounds were elucidated by classical spectroscopic methods including UV, NMR, MS and HR-MS.

Samples of the Himalayan medicinal plant Swertia chirata obtained from a local market in Nepal, from a micropropagated field cultivated clone, and from two in vitro-clones were compared by means of HPLC. The substance patterns of methanolic and dichloromethane extracts of the in vivo grown materials showed good conformity while in the samples from tissue culture major compounds were missing. Our findings confirm that the secondary metabolism of in vitro-cultivated plants normally differs from that of plants in their natural environment. Furthermore, the compound pattern of plants produced through micropropagation and subsequently cultivated in the field is comparable to that of plants collected from the wild. As an alternative to the uncontrolled depletion of the natural resources a sustainable use of Swertia chirata could hence be achieved by controlled field culture of micropropagated plants.

Different natural products from the plant kingdom including isoflavones, prenylflavones, coumestans, stilbenes, and lignans can cause endocrine perturbations, especially on the estrogenic hormonal pathway because of their structural analogies to estradiol. Several studies report the presence of such compounds in food, the richest source being soy and soy products. These substances, commonly called phytoestrogens, are known to influence the human hormonal profile and soy preparations are being considered for use as post-menopausal estrogen replacement therapy. Numerous clinical and epidemiological reports have studied the influence of phytoestrogens on the development of hormone-dependent cancers. The effect on genital development of postnatal phytoestrogen exposure is still under debate. Consumption of phytoestrogens may also influence the incidence of bone diseases, atherosclerosis, or Alzheimer's disease. This article summarizes the classification of phytoestrogens, their pharmacological evaluation and properties, and the methods used for their identification.