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Three new norbergenin derivatives, 11-O-p-hydroxybenzoylnorbergenin, 4-O-(3′-methylgalloyl)norbergenin and 4-O-syringoylnorbergenin were isolated from the stem bark of Diospyros sanza-minika, along with three known compounds: norbergenin, 4-O-galloylnorbergenin and quercitol. Their structures were established on the basis of 1D and 2D NMR experiments and mass spectrometry. Some of the above compounds showed radical scavenging properties in a DPPH solution assay.

Extracts of Withania adpressa Coss. (Solanaceae), a medicinal plant endemic to Moroccan Sahara, were tested for their cytotoxicity towards a panel of cancer cell lines (Hep2, HT29, RD, Vero and MDCK), using the (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide) [MTT assay, Sigma-Aldrich]. The bioassay-guided fractionation of this plant extracts results a novel withanolide 14α,15α,17β,20β-tetrahydroxy-1-oxo-(22 R )-witha-2,5,24-trienolide and the already identified withanolides F and J extract, semi-purified fractions and pure compounds exhibits potent cytotoxicity against human cancer cell lines tested, in dose-dependant manner. Morphological features of treated Hep2 cells with the novel withanolide and characteristic DNA fragmentation revealed that the cytotoxicity was due to induction of apoptosis. Taken together, the results suggest that withanolides from W . adpressa Coss. hold potential as antiproliferative agents.

Crude extracts of roots and stems of Polygonum cuspidatum Sieb. and Zucc. and Polygonum sachalinensis F. Schmidt ex Maxim from China and Switzerland were analyzed by online HPLC/UV/ESI-MS to ascertain the phytochemical differences between the original and invasive exotic varieties. A total of 36 constituents were identified by comparing their retention times, UV data, mass spectra with those of standards or with literature data. Certain constituents, such as flavanol gallate dimers, were reported for the first time from these species. The relative quantities of the major compounds (emodin glucoside, piceid, resveratroloside and piceatannol glucoside) differed in the samples of the Polygonum species from China and from Switzerland. Phenylpropanoid glucosides were the main constituents of the roots and stems of P. sachalinensis , while the roots of P. cuspidatum were characterized by the presence of stilbenes and anthraquinones.

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.

From the alkalised crude extract of Symphytum cordatum (L.) W.K. roots, pyrrolizidine alkaloids (PAs) were extracted as free tertiary bases and polar N-oxides in a merely one-step liquid-liquid partitioning (LLP) in separation funnel and subsequently pre-fractionated by preparative multiple-development (MD) thin-layer chromatography (TLC) on silica gel plates. In this way three alkaloid fractions of different polarities and retention on silica gel plates were obtained as: the most polar N-oxides of the highest retention, the tertiary bases of medium retention, and diesterified N-oxides of the lowest retention. The former fraction was reduced into free bases by sodium hydrosulfite and purified by LLP on Extrelut-NT3 cartridge. It was further analysed together with the two other fractions by high-performance liquid chromatography (HPLC)-ion-trap mass spectrometry with atmospheric pressure chemical ionization (APCl) interface on XTerra C-18 column using a gradient elution. Based on MSn spectra, 18 various alkaloids have been tentatively determined for the first time in this plant as the following types of structure: echimidine-N-oxide (three diasteroisomers), 7-sarracinyl-9-viridifloryiretronecine (two diasteroisomers), echimidine (two diasteroisomers), lycopsamine (two diasteroisomers), dihydroechinatine-N-oxide, dihydroheliospathuline-N-oxide, lycopsamine-N-oxide (three diasteroisomers), 7-acetyllycopsamine-N-oxide, symphytine-N-oxide (two diasteroisomers) and 2 '',3 ''-epoxyechiui-nine-N-oxide. (c) 2006 Elsevier B.V. All rights reserved.

Apple polyphenols were characterised by means of hyphenated techniques such as HPLC coupled to UV photodiode array detection (LC-DAD) and to mass spectrometry (LC-MS). LC-MS using atmospheric pressure ionisation (APCI) in the positive ion mode provided the molecular weight, the number of hydroxyl groups, the number of sugars and an idea about the substitution pattern of the polyphenols. LC-DAD with postcolumn addition of UV shift reagents afforded precise structural information about the position of the free hydroxyl groups in the polyphenolic nucleus. Five isorhamnetin glycosides, two hydroxyphloretin glycosides and quercetin were reported in apple peel for the first time. Postcolumn addition of UV shift reagents in LC-DAD analysis confirmed the presence of isorhamnetin glycosides and not the isomeric glycosides of rhamnetin. Moreover, isorhamnetin-3-O-rhamnoglucoside was identified unambiguously by comparison with a standard. These results are relevant not only from a chemotaxonomic point of view, but also in the control of authenticity of fruit derived products in order to detect fraudulent admixtures. (C) 2004 Elsevier B.V. All rights reserved.

A generally applicable method for HPLC analysis of sugar nucleotides was established. Separation was achieved using ion-pair chromatography on a reversed-phase column. Ion-pair reagents were selected and various parameters optimized with respect to separation of I I of the most important sugar nucleotides and compatibility with on-line detection by electrospray ionization MS and NMR. The method was applied to the on-line analysis of the GDP-D-mannose-4,6-dehydratase (Gmd) and GDP-4-keto-6-deoxy-D-mannose reductase (Rmd) catalyzed conversion of GDP-D-mannose to GDP-D-rhamnose. By LC-NMR, the intermediate product of the reaction was shown to be a mixture of GDP-4-keto-6-deoxy-D-mannose and GDP-3-keto-6-deoxy-D-mannose. Nucleotide co-factors of enzymatic reactions such as ATP and NADH did not interfere with the analysis of nucleotide-activated sugars. (C) 2004 Elsevier B.V. All rights reserved.

Eight furanocoumarins, one coumarin and four acridone derivatives have been identified in the roots of Thamnosma rhodesica (Rutaceae). Rhodesiacridone, one of these acridone derivatives, is reported here for the first time. Its structure was elucidated by spectrometric methods including ESI-HR, EI, DCI mass spectrometry, H-1, C-13 and 2D NMR experiments. This novel compound showed activities against the intracellular form of a human pathogen, the protozoan parasite Leishmania major. Two known acridone related compounds, gravacridonediol and 1-hydroxy-10-methylacridone, exhibited activities against the intracellular form of the same parasite and the fungus Cladosporium cucumerinum, respectively. (C) 2004 Elsevier Ltd. All rights reserved.

Five isopimarane diterpenes (7beta-hydroxyisopimara-8,15-dien-14-one, 14alpha-hydroxyisopimara-7,15-dien-1-one, 1beta, 14alpha-dihydroxyisopimara-7,15-diene, 7beta-hydroxyisopimara-8(14),15-dien-1-one and 7beta-acetoxyisopimara-8(14),15-dien-1-one) have been isolated from the leaves of Hypoestes serpens (Acanthaceae). All compounds exhibited antifungal activity against both the plant pathogenic fungus Cladosporium cucumerinum and the yeast Candida albicans; two of them also displayed an acetylcholinesterase inhibition. The structures of the Compounds were determined by means of spectrometric methods, including 1D and 2D NMR experiments and MS analysis. (C) 2003 Published by Elsevier Ltd.

A new triterpenoid saponin was isolated from the roots of Silene cucubalus and its structure was determined on the basis of one- and two-dimensional NMR spectroscopy as gypsogenin 3-O-beta-xylopyranosyl-(1-->3)-[beta-galactopyranosyl-(1-->2)]-beta-glucuronopyranoside. A known saponin, quillaic acid 3-O-beta-xylopyranosyl-(1-->3)-[beta-galactopyranosyl-(1-->2)]-beta-glucuronopyranoside, was also isolated.

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.

LC-MS-MS is becoming a very important tool for the on-line identification of natural products in crude plant extracts. For an efficient use of this technique in the dereplication of natural products, a careful study of the parameters used to generate informative MS-MS spectra is needed. In this paper, the collision-induced dissociation (CID) MS-MS spectra of ubiquitous C-glycosidic flavonoids have been systematically studied using hybrid quadrupole time-of-flight and ion-trap (IT) mass analysers under various CID energy conditions. Efficient differentiation of flavonoid C-glycoside isomers was possible, based on the comparison of CID-MS-MS spectra of particular C-glycoside unit fragments. Striking differences between 6-C and 8-C flavonoid glycosides were especially observed in the product ion spectra of their 0.2X+ fragments ([M+H-120]+). Some guidelines for the on-line characterisation of C-glycosidic flavonoids by LC-MS-MS or LC-multiple-stage MS are given.

Two new cyclobutane-type lignans, named moslolignans A and B, together with two known ones, andamanicin and magnosalin, were isolated from the whole plant of Mosla scabra. Their structures were established as 1 beta*,2 beta*,3 alpha*,4 alpha*-l,2-dimethyl-3-(3- methoxy-4,5-methylene-dioxyphenyl)-4-(2,4,5-trimethoxyphenyl)-cyclobutane and 1 beta*,2 beta*,3 alpha*,4 alpha"-1,2-dimethyl-3-(2,5-dimethoxy-3,4-methylenedioxyphenyl)-4-(2,4, 5-trimethoxyphenyl)-cyclobutane by spectroscopic methods. This is the first report of naturally-occurring cyclobutane-type lignans with asymmetrical substitutions. (C) 2000 Elsevier Science Ltd. All rights reserved.

A new dihydrochalcone, 6''-acetylphloridzosid, was isolated from the whole plant of Loiseleuria procumbens (L.) Desv. and identified as 2'-O-(6''-O-acetylglucopyranosyl)-4,4',6'-trihydroxydihydrochal cone by spectroscopic methods. In addition, one stilbene and three other dihydrochalcones were identified as (E)-piceid, phloretin (2',4,4',6'-tetrahydroxydihydrochalcone), phloridzosid (2'-O-glucopyranosyl-4,4',6'-trihydroxydihydrochalcone) and asebotin (2'-O-glucopyranosyl-4'-methoxy-4,6'-dihydroxydihydrochalcone), respectively. Some of these compounds showed scavenging properties towards the 2,2-diphenyl-1-picrylhydrazyl radical and antioxidant properties in a test with lysozyme.

Ginkgolic acids (GAs) are toxic phenolic compounds present in the fruits and leaves of Ginkgo biloba L. (Ginkgoacae). Their maximum level in phytopharmaceuticals containing ginkgo extracts has been recently restricted to 5 microg/g by the Commission E of the former Federal German Health Authority. In order to detect ginkgolic acids at these low levels, a sensitive and selective analytical method, based on liquid chromatography-electrospray mass spectrometry (LC-ES-MS) has been developed. The three main phenolic acids (1-3) of the chloroform fruit extract were isolated and used as standards for quantification. In the LC-ES-MS negative ion mode, calibration curves with good linearities (r=0.9973, n=6) were obtained in the range of 0.5-10 microg/g for compounds 1, 2 and between 0.1 and 7.5 microg/g (r=0.9949, n=6) for ginkgolic acid 3. The detection limits at a SIN ratio of 3 were 0.1 (3) and 0.25 microg/g (1, 2). Recoveries were around 101% at 5 microg/g for the substances detected in the leaf extracts. Good precision was achieved with relative standard deviations of less than 4% (n=6). The optimised method was applied to verify whether the amount of gingkolic acids was below 5 microg/g in a standardised leaf extract which is a constituent of a phytopreparation.

In addition to the known cordiaquinones A and B, two novel meroterpenoid naphthoquinones, named cordiaquinones J and K, have been isolated from the roots of Cordia curassavica. Their structures were elucidated by spectrometric methods including EI, D/CI mass spectrometry, 1H, 13C and 2D-NMR experiments. The four naphthoquinones demonstrated antifungal activities against Cladosporium cucumerinum, Candida albicans and toxic properties against larvae of the yellow fever-transmitting mosquito Aedes aegypti.

A new phenolic glycoside, 1-(α- l -rhamnosyl(1-6)-β- d -glucopyranosyloxy)-3,4,5-trimethoxybenzene, together with the alkaloid N -( p -coumaroyl)-tryptamine and four known flavonoids were isolated from the methanolic bark extract of Ravensara anisata Danguy (Lauraceae). Their structures have been established by NMR spectroscopy, and chemical methods.

The leaves and bark dichloromethane extracts of Ravensara anisata showed antifungal activity against the yeast Candida albicans and the phytopathogenic fungus Cladosporium cucumerinum in bioautographic TLC assays. Activity-guided fractionation afforded two new α-pyrones: 6R∗-(4R∗-acetoxy-2S∗-hydroxy-8-phenyloctyl)-5,6-dihydro-2-H-pyran-2-one and 6R∗-(2S∗-acetoxy-4R∗-hydroxy-8-phenyloctyl)-5,6-dihydro-2-H-pyran-2-one. Their structures have been established by NMR spectroscopy, chemical methods and X-ray crystallographic analysis. The antifungal activity against C. albicans and C. cucumerinum was determined for both compounds.

Three new phenolic glycosides named eriosemasides A–C, one novel (named eriosematin F) and four known phenolic constituents were isolated from the n -BuOH-soluble fraction of the roots of Eriosema tuberosum . Their structures were established by spectroscopic analyses and chemical methods. All the phenolic compounds were fungitoxic except the phenolic glycosides.

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.

Seven compounds have been isolated from methanol extracts of whole Saxifraga stellaris (Saxifragaceae) plants. They were identified as the new compound, 6- O -galloyl fructose, together with 3- O -[2- O -(β- d -xylopyranosyl)-β- d -galactopyranosyl]-kaempferol, 3- O -[2- O -(β- d -xylopyranosyl)-β- d -galactopyranosyl]-quercetin, trifolin, hyperin, resveratrol-3- O -glucoside, triandrin, by chemical and spectroscopic methods. Their free radical scavenging properties are also described.

From the root bark of Triphyophyllum peltatum, the new naphthylisoquinoline alkaloid 5'-O-demethyldioncophylline A has been isolated. Its otherwise difficult separation from the largely dominating main alkaloid, dioncophylline A, was greatly facilitated by a bromination-benzylation procedure. From the resulting derivative, a crystal structure analysis with an anomalous X-ray diffraction was achieved, allowing confirmation of the full absolute stereostructure of the new alkaloid. The structure was further corroborated by a partial synthesis from dioncopeltine A. The natural product was shown to exhibit antimalarial activity against erythrocytic forms of Plasmodium falciparum.

Six prenylated benzoic acid derivatives and three chalcones have been isolated from the dichloromethane extract of the leaves of Piper dilatatum (Piperaceae). Their structures were elucidated by means of mass spectrometry, UV and NMR spectroscopy. Four of the benzoic acid derivatives displayed antifungal properties against Cladosporium cucumerinum in direct bioautography on TLC plates. Taboganic acid has been obtained for the first time from plant origin.

Five isoflavonoid glycosides together with the corresponding aglycones have been isolated from the n-BuOH-soluble fraction of a methanol extract of the roots of Eriosema tuberosum. One compound is new and its structure has been established by spectroscopic analyses and chemical methods as 5-O-methylgenistein 7-O-β- d -apiofuranosyl-(1 → 6)-O-β- d -glucopyranoside.

A new flavonoid, dihydrorhamnetin 3- O - β -d-arabinopyranoside, was isolated from Pyrola elliptica , together with quercetin 3- O - β -d-glucopyranoside, quercetin 3- O - α -l-arabinofuranoside, quercetin 3- O - β -d-galactopyranoside, rhamnetin 3- O - β -d-galactopyranoside, taxifolin 3- O - β -d-arabinopyranoside, taxifolin 3- O - β -d-xylopyranoside, homoarbutin, isohomoarbutin and monotropein.

Two new diterpenes ( 1 and 2 ) named mellerin A and B along with three known sterols ( 3 – 5 ) were isolated from the leaves of Neoboutonia melleri (Euphorbiaceae). Their structures were identified on the basis of chemical and spectroscopic methods.

The new flavonol quercetin-3- O -[3,4 diacetyl-α-l-rhamnopyranosyl-(1–6)β-d-glucopyranoside], 2′( S ),3′( R )-2′-acetoxyisopropyl-3′-acetoxy-2′,3′dihydroangelicin were fully elucidated together with 11 other flavonoids and bioactive coumarins from Tordylium apulum . A new flavonol diglycoside, quercetin-3- O -[3,4 diacetyl-α-l-rhamnopyranosyl-(1–6)β-d-glucopyranoside] and an antifungal dihydrofuranocoumarin, 2′( S ),3′( R )-2′-acetoxyisopropyl-3′-acetoxy-2′,3′-dihydroangelicin, together with four other known flavonoids and seven known bioactive coumarins, were isolated from the aerial parts of Tordylium apulum and their structures elucidated by NMR and mass spectroscopy.

Five novel sesquiterpene glycosides named dictamnosides A-E were isolated from the methanol extract of the root bark of Dictamnus dasycarpus. Their structures were established on the basis of X-ray diffraction, spectroscopic and chemical methods.

Two novel triterpenoid saponins, named mussaendosides U and V, together with one known saponin and four known triterpenes were isolated from the aerial parts of Mussaenda pubescens (Rubiaceae). The structures were determined on the basis of chemical analysis ad spectral methods. All these compounds were identified for the first time from the genus Mussaenda.

Wahlenbergioside, a new hydroxymethylglutaroyl phenylpropanoid glucoside, and a known compound, lobetyolin, were isolated from the methanol extract of Wahlenbergia marginata . The structures were determined by spectroscopic analysis and chemical degradations.

Phytochemical investigation of the methanolic extract of Gentiana linearis roots led to the isolation of two novel iridoids (7-O-coumaroyl-loganic acid; 7-O-(4″-O-glucosyl)coumaroyl-loganic acid) and a new secoiridoid (6″″-O-glucosyltrifloroside) together with trifloroside, gentiopicroside, isovitexin and isosaponarin. The structures have been elucidated by MS and NMR spectral data, enzymic and chemical degradation. The chemotaxonomic significance of the isolated secoiridoids and iridoids is briefly discussed.

Two new prenylated chromones, eriosematins D and E, have been isolated from a dichloromethane extract of the roots of Eriosema tuberosum . Their structures were elucidated by spectroscopic methods, including 2D NMR heteronuclear correlation spectra. In solution, both compounds were shown to be in equilibrium at room temperature; stable derivatives were obtained after acetylation. Both chromones exhibited antifungal activity against Cladosporium cucumerinum and Candida albicans in TLC bioautographic assays.

Phytochemical investigation of two batches of Mariscus psilostachys led to the isolation and characterization of five flavans and three flavanones. Two flavans are new natural products and their structures have been established as (2S)-4′-hydroxy-5,7,3′-trimethoxyflavan and (±)-5,4′-dihydroxy-7-3′-dimethoxyflavan. Absolute configuration of the optically active compound isolated has been determined on the basis of its CD spectrum. Antimicrobial activity against Candida albicans and Cladosporium cucumerinum were determined for all compounds. The less polar flavans showed to be more active in both TLC assays and dilution assays.

Investigation of the metabolites of Gentiana rhodantha by LC-UV and LC-mass spectrometry (MS) resulted in the isolation and identification of two further high molecular weight secoiridoid glycosides, rhodanthosides B and C. These compounds contain four secoiridoid glucoside moieties, two of which were linked with a monoterpene dicarboxylic acid. Their structures were established by LC-UV, TSP LC-MS, CF-FAB LC-MS, ES/LC-MS, FAB-MS and 1D and 2D NMR data in combination with chemical reactions. Copyright (C) 1996 Elsevier Science Ltd

Four new xanthones have been isolated from the roots of Hypericum roeperanum . Their structures have been established by a combination of spectroscopic and chemical methods as 1,6-dihydroxy-5-methoxy-4′,5′-dihydro-4′,4′,5′-trimethylfurano-(2′,3′:3,4)-xanthone (5- O -methyl-2-deprenylrheediaxanthone B), 1,6-dihydroxy-5-methoxy-6′,6′-dimethylpyrano-(2′,3′:3,4)-xanthone (5- O -methylisojacareubin), 1,3,5,6-tetrahydroxy-2-(2′,2′-dimethyl-4′-isopropenyl)-cyclopentanylxanthone (5- O -demethylpaxanthonin) and 1,3,5,6-tetrahydroxy-4- trans -sesquilavandulylxanthone (roeperanone). In addition, 2-hydroxyxanthone, 5-hydroxy-2-methoxyxanthone, 1,5-dihydroxy-2-methoxyxanthone, 2-deprenyl rheediaxanthone B, isojacareubin and calycinoxanthone D have been isolated and characterized. Some of the isolated xanthones exhibited antifungal activity against Candida albicans .

A new flavonol glycoside has been isolated from the leaves of Vernonia galamensis ssp. nairobiensis . Its structure has been established as isorhamnetin 3-O-β- d -apio- d -furanosyl (1→2)-β- d -galactopyranoside on the basis of spectral data (UV, 1 H and 13 C NMR, D/CIMS) and by acid hydrolysis. Characterization of the peracetate derivative confirmed the configuration of the apiosyl moiety. In addition, the known flavonol glycosides; quercetin 3-galactoside, quercetin 3-apiosyl(1→2)galactoside and quercetin 3-rhamnosyl(1→6)galactoside have been isolated and identified.

LC-UV-mass spectrometry and bioassay co-directed fractionation of an aqueous acetone extract of the roots of Gentiana macrophylla gave three new chromene derivatives and two novel and six known secoiridoids, along with kurarinone, kushenol I, beta-sitosterol, stigmasterol, daucosterol, beta-sitosterol-3-O-gentiobioside, alpha-amyrin, oleanolic acid, isovitexin, gentiobiose and methyl 2-hydroxy-3-(1-beta-D-glucopyranosyl)oxybenzoate. The structures of the new products were established from spectral and chemical evidence as 2-methoxyanofinic acid and macrophyllosides A-D. The six known secoiridoids were gentiopicroside, sweroside, 6'-O-beta-D-glucosylgentiopicroside, 6'-O-beta-D-glucosylsweroside, trifloroside and rindoside. The new acid (2-methoxyanofinic acid), its methyl ester, kurarinone and kushenol I were shown to be active against the plant pathogenic fungus Cladosporium cucumerinum. The methyl ester and kurarinone inhibited also the growth of the human pathogenic yeast Candida albicans. Structure-activity relationships were studied. Thus, addition of a methoxyl group to the benzene nucleus of anofinic acid (2,2-dimethyl-2H-1-benzopyran-6-carboxylic acid) increased the antifungal activity remarkably whereas glycosylation at the carboxylic moiety was found to remove the activity. Esterification of the new acid induced its activity against C. albicans, but decreased its growth inhibition properties against C. cucumerinum. Hydroxylation of kurarinone at the 3 beta-position removed its activity against C. albicans and decreased the inhibition of C. cucumerinum. In addition, the chemotaxonomic significance of the identified constituents is discussed.

One 1H-cyclopentatetrahydro[b]benzofuran, two lignans, two dammarane triterpenoids and one limonoid were isolated from the bark of Aglaia elaeagnoidea. The structures of the isolated compounds were established on the basis of spectral data. The lignan trans-2,3-bis(3,4,5-trimethoxybenzyl)-1,4-butanediol diacetate and 20S,24S-epoxy-25-hydroxymethyldammarane-3-one are new compounds. trans-3,4-Bis(3,4,5-trimethoxybenzyl)tetrahydrofuran has been synthesized, but not previously reported as a natural product.

Seven pentacyclic triterpenes and triterpene glycosides have been isolated from the stems and roots of Paradrymonia macrophylla and their structures elucidated by means of 1H and 13C NMR spectroscopy. Three of them are described for the first time as natural products, namely: 2α,3β,19α-trihydroxy-24-oxo-urs-12-en-28-oic acid (24-epi-pinfaensic acid), 2α,3β,19α-trihydroxy-24-oxo-urs-12-en-28-oic acid ester glucoside (24-epi-pinfaensin) and 2α,3β,19α-trihydroxy-24-oxo-olean-12-en-28-oic acid ester glucoside (paradrymonoside).

Three new phloroglucinols (hyperbrasilols B and C, and isohyperbrasilol B) have been isolated from a petrol extract of the leaves and flowers of Hypericum brasiliense. Their structures were established by spectroscopic methods including two-dimensional-NMR heteronuclear correlations. EI and D/Cl-mass spectral, NMR, IR and UV data are reported. All three phloroglucinols were antibacterial against Bacillus subtilis in a TLC bioautographic assay.

Four new prenylated chromones have been isolated from a dichloromethane extract of the roots of Eriosema tuberosum. Their structures were elucidated by spectroscopic methods. Eriosematin A exhibited antifungal activity against Cladosporium cucumerinum and Candida albicans in TLC bioautographic assays.

Fractionation of an aqueous acetone extract of the whole herb of Gentiana algida gave one new [2'-(o,m-dihydroxybenzyl)sweroside] and five known secoiridoids, together with anofinic acid, fomannoxin acid, sitosterol, daucosterol, stigmasterol, oleanolic acid, orientin and gentianose. The structures were determined by spectral methods and a few chemical transformations. Anofinic acid and fomannoxin acid were found to be active against Cladosporium cucumerinum, a plant pathogenic fungus. Preliminary structure-activity studies indicated that the presence of carboxylic moieties in these acids was presumably a precondition for activity, whereas their methyl esters, inactive to the fungus, were active against the human pathogenic yeast Candida albicans. The chemotaxonomic significance of the isolates is discussed briefly.

An improved method is presented for the isolation of phenolic compounds from needles of Norway spruce ( Picea abies , Pinaceae). High-speed counter-current chromatography (HSCCC) has been employed as a key step in the semipreparative-scale separation and purification of 26 phenolics from juvenile and mature needles. The isolation of the three 3- O -(6″Ac)glucosides syringetin, isorhamnetin and kaempferol is reported together with other flavonols, dihydroflavonols, catechins, stilbenes, and other phenolics.

Nine xanthone aglycones and one xanthone glycoside have been identified in Schultesia lisianthoides . Seven of the aglycones have been isolated and their structures elucidated by UV, mass and NMR spectroscopy; three xanthones were identified on-line by HPLC-UV and HPLC-mass spectrometry. 5-Hydroxy-1,2,3-trimethoxyxanthone is a new natural product. The other constituents have already been encountered in different Gentianaceae species.

The novel flavonol, syringetin 3- O -(6″-acetyl)- β -glucopyranoside, has been isolated from needles of Norway spruce ( Picea abies ) together with the 3- O -(6″-acetyl)- β -glucopyranosides of isorhamnetin and kaempferol, the 3- O -(6″- α -rhamnopyranosyl)- β -glucopyranosides of laricitrin, isorhamnetin, myricetin, quercetin and kaempferol and the 3- O - β -glucopyranosides of laricitrin, isorhamnetin, myricetin, quercetin and kaempferol. Most of the flavonols have been isolated for the first time from Norway spruce. Kaempferol 3- O -(6″-acetyl)- β -glucopyranoside has previously been isolated from Senecio aureus , but without determination of the binding site of the acetyl group. Structure determination of the flavonols was achieved from TLC, 1 H NMR and UV shift reagent data, and, in most cases, 13 C NMR and MS.

Three new xanthone glycosides and a rare flavonoid glycoside have been isolated from the whole plant methanolic extract of Halenia corniculata (Gentianaceae). They were identified as 2,3,7-trimethoxy-1-O-primeverosyloxyxanthone, 2,3,4,7-tetramethoxy-1-O-primeverosyloxyxanthone, 2,3,4,5,7-pentamethoxy-1-O-primeverosyloxyxanthone and 7-O-primeverosylluteolin. Combined HPLC-UV and thermospray MS analyses of both dichloromethane and methanolic crude extracts permitted the detection of six other new xanthones, tentatively identified by on-line data. Among these, one was an aglycone, 1-hydroxy-2,3,4,5,7-pentamethoxyxanthone and five were 1-O-glycosides: 7-hydroxy-2,3,4,5-tetramethoxy-1-O-primeverosyloxyxanthone, 7-hydroxy-2,3,4,5-tetramethoxy-1-O-gentiobiosyloxyxanthone, 2,3,7-trimethoxy-1-O-gentiobiosyloxyxanthone, 2,3,4,7-tetramethoxy-1-O-gentiobiosyloxyxanthone and 2,3,4,5,7-pentamethoxy-1-O-gentiobiosyloxyxanthone. Systematic use of an in-house UV database and complementary on-line MS data enabled the identification of 16 known secoiridoids, flavonoids and xanthones.

In crude plant extracts, constituents of biological or pharmaceutical interest often exist in the form of glycosides. Off-line mass spectral investigations of these metabolites require soft ionisation techniques such as desorption chemical ionisation (DCI) or fast atom bombardment (FAB) if information on molecular mass or sugar sequence is desired. In LC-MS, glycosides can be ionised by using thermospray (TSP), continuous-flow fast atom bombardment (CF-FAB) or other interfaces. These techniques are thus potentially applicable to the on-line analysis of glycosides and can be applied to plant extract analysis. Thermospray (TSP) used with ammonium acetate as buffer provides mass spectra similar to those obtained with DCI-MS using NH3 and is potentially applicable to the on-line analysis of relatively small glycosides bearing no more than three sugar units. CF-FAB provides cleaner MS spectra than static FAB due to the lower concentration of the matrix used and can be applied to more polar compounds such as glycosides with a larger number of sugars. The use of a special setup involving post-column addition of the buffer or the matrix and splitting allows LC-UV, TSP LC-MS and CF-FAB LC-MS to be performed with the same standard HPLC conditions. Different crude plant extracts containing various types of glycosides with one to eight sugar units have been analysed by both TSP and CF-FAB. Cardenolides from Nerium odorum (Apocynaceae) and saponins from Swarzia madagascariensis (Leguminosae), Aster scaber and Aster tataricus (Asteraceae) have been studied by LC-MS. The combination of these two interfaces for the HPLC screening of crude plant extracts is discussed.

Conventional HPLC analysis of the sesquiterpene aryl esters present in the crude extracts of the pathogenic basidiomycete Armillaria is complicated by difficulties in identification solely on the basis of retention time. On-line coupling of liquid chromatography with thermospray mass spectrometry (LC-TSP-MS) provides a means for their direct detection. Crude extracts of seven Armillaria species were analysed providing a semi-quantitative survey of sesquiterpene aryl ester production within the genus. The distribution of these metabolites and its significance with regard to species differentiation and pathogenicity are discussed. Unknown components were also detected by on-line LC-TSP-MS screening of extracts, facilitating a targeted isolation route.