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Five labdane (1-5), an isolabdane (6), and five clerodane diterpenoids (7-11), were isolated from seeds, husks, and leaves of Colophospermum mopane. Compounds 1-3 and 6-9 are new, and their structures were elucidated by means of physical data analysis (1D and 2D NMR, HRESIMS). The absolute configurations of 1, 7, and 10 were determined by single-crystal X-ray diffraction with Cu Kα radiation. For compounds 2 and 6, the absolute configurations were established by the modified Mosher's method and corroborated by comparison of experimental and calculated electronic circular dichroism spectra of their 3-p-bromobenzoate derivatives. The crude extracts and compounds were evaluated for antimicrobial activity. The leaf extract was the most active against Staphylococcus aureus (125 μg/mL). Compound 11 showed the best inhibitory activity, with minimum inhibitory values of 15.6 μg/mL against Escherichia coli and Staphylococcus aureus and 31.3 μg/mL against Enterococcus faecalis.

Two new flavonolacyl glucosides, 3- O -methylquercetin 7- O -[ β -D-6″-( E - p -coumaroyl) glucopyranoside] (1) and 3,4′-di- O -methylquercetin 7- O -[ β -D-6″-( E - p -coumaroyl) glucopyranoside] (2), four known flavonol glycosides (3–5, 7) and one known dihydroflavonolglucoside (6) were isolated from the aril part of Schotia brachypetala with high-speed countercurrent chromatography (HSCCC) as the primary chromatographic technique. The structures of the isolated compounds were elucidated with spectroscopic and spectrometric methods and acid hydrolysis. The 1,1-diphenyl-2-picrylhydrazyl (DPPH) antioxidant, antibacterial and antimalarial activities of selected isolates were evaluated. Strong to moderate antioxidant activity (lowest IC 50 of 15.2 μM), moderate to weak antibacterial activity (lowest MIC of 0.13 mg/mL) and moderate antimalarial activity (lowest IC 50 of 5.18 μg/mL) compared to the positive controls were observed.

The biological properties of verbascoside are numerous and include antimicrobial activities. As part of a drive to identify alternatives to synthetic fungicides for crop protection, this study was aimed at investigating methods of preparing verbascoside-rich plant extracts from viable sources of the compound and monitoring its stability under various conditions. Leaf extracts of Lippia javanica Spreng. and Lantana camara Linne (Verbenaceae) were partially purified using column chromatography and high speed centrifugal countercurrent chromatography, the latter yielding fractions with higher purity (71%) than those from a single column chromatographic separation (38–44% pure). Verbascoside remained stable upon heating, but was completely decomposed after four hours exposure of the extract to sunlight. Compared to the other storage conditions, the compound was best preserved in a dry form in the dark. Analysis by high performance liquid chromatography revealed that the verbascoside content of plant parts of L. camara from natural populations was highly variable, both within and between populations. However, several specimens produced high levels of the compound (Hazyview: Plant 3 (83.0 mg/g dry weight), Magoebaskloof 2: Plant 5 (64.8 mg/g) and White River: Plant 2 (64.0 mg/g)), suggesting that L. camara is an excellent source of verbascoside. Extracts of the plant displayed effective in vivo inhibition of Penicillium digitatum on oranges.

Phytochemical investigation of the dried bark of Millettia mannii resulted in the isolation of two isoflavones (1 and 2), one furanonaphthoquinone (3) and five triterpenoids (4−8). Except for compound 2, all the isolated compounds are reported here for the first time from this plant. The chemotaxonomic significance of these compounds was discussed.

Many of the protein kinase activators and inhibitors presently under investigation are natural products or are derivatives of natural products. Since over 500 kinases are encoded by the human genome, the task is to discover modulatory compounds which have high specificity for a single enzyme. Many different low molecular weight compounds have been studied for activity. These come from various sources, such as plants, marine organisms, microorganisms and cyanobacteria. The search for specific inhibitors is mainly performed in cell-based assays.

The alkaloids of Sceletium tortuosum (Mesembryanthemaceae) exhibit important pharmacological properties and are used for the treatment of psychiatric and psychological conditions, including depression, anxiety, drug dependence, bulimia and obsessive-compulsive disorder. The all-liquid technique of high-speed countercurrent chromatography provides an excellent tool for the rapid isolation of these alkaloids in high yields.

Three glucosylated resveratrol analogues (piceid, piceatannol glucoside, resveratroloside) were successfully isolated from the crude MeOH extract of the invasive plant species Polygonum cuspidatum by semi-preparative high-speed countercurrent chromatography with a two-phase solvent system composed of cyclohexane-ethyl acetate-methanol-water (1:5:1:5, v/v/v/v). Piceid (23 mg), resveratroloside (17 mg), piceatannol glucoside (15 mg) of purities over 80% were isolated from 500 mg crude MeOH extract in one step. Subsequent passage over a SPE column was used to quickly bring their purities to over 90%. The purities were determined by HPLC analysis and their structures were elucidated by proton nuclear magnetic resonance ((1)H-NMR), HMBC, ESI-MS and HR-MS.

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.

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.

Various natural products, such as physostigmine, have long been recognized as inhibitors of the enzyme acetylcholinesterase. Since the recent approval of galanthamine for the treatment of Alzheimer's disease by the blockage of acetylcholine degradation, attempts to find other inhibitors of the enzyme have multiplied, leading to promising candidates such as huperzine A. In this review, a listing is presented of natural product inhibitors, both alkaloid and non-alkaloid in origin. These have been isolated from plant, animal and microbial sources. Details of current testing methods on cholinesterases are given, including solution assays and screening techniques by TLC and HPLC.

A fruit pulp extract of Detarium microcarpum showed inhibition of the growth of the plant pathogenic fungus Cladosporium cucumerinum and of the enzyme acetylcholinesterase, implicated in Alzheimer's disease. Fractionation of this extract led to the isolation of four new clerodane diterpenes, 3,4-epoxyclerodan-13E-en-15-oic acid ( 1), 5 alpha, 8 alpha-(2-oxokolavenic acid) ( 2), 3,4-dihydroxyclerodan-13E-en-15-oic acid ( 4), and 3,4- dihydroxyclerodan-13Z-en-15-oic acid ( 5). Also isolated were 2-oxokolavenic acid ( 3) and copalic acid ( 6). Structure elucidation of the compounds was carried out by spectroscopic data interpretation and by the X-ray crystallography of 2 and 4. Three of the new clerodane diterpenes ( 1, 2, and 5) showed both antifungal activity and inhibition of acetylcholinesterase, and 3 showed a slight inhibition of this enzyme.

Nine new tropane alkaloids substituted by a methylpyrrole moiety were isolated from the bark of Erythroxylum vacciniifolium, a Brazilian endemic plant used in traditional medicine and locally known as catuaba. All compounds were elucidated as tropanediol or -triol alkaloids esterified by at least one 1-methyl-1H-pyrrole-2-carboxylic acid. One of the isolated compounds was identified as a tropane alkaloid N-oxide. Their structures were determined by high-resolution mass spectrometry and multidimensional NMR spectroscopy.

PurposeThis paper aims to provide a brief re´sume´ of previous research which has analysed the impact of e‐commerce on retail real estate in the UK, and to examine the important marketing role of the internet for shopping centre managers, and retail landlords.Design/methodology/approachBased on the results from a wider study carried out in 2003, the paper uses case studies from two different shopping centres in the UK, and documents the innovative uses of both web‐based marketing and online retailing by organisations that historically have not directly been involved in the retailing process.FindingsThe paper highlights the importance of considering online sales within a multi‐channel approach to retailing. The two types of emerging shopping centre model which are identified are characterised by their ultimate relationship with the physical shopping centre on whose web site they reside. These can be summarised as: the “centre‐led” approach, and the “brand‐led” or “marketing‐led” approach.Research limitations/implicationsThe research is based on a limited number of in‐depth case studies and secondary data. Further research is needed to monitor the continuing impact of e‐commerce on retail property and the marketing strategies of shopping centre managers and owners.Practical implicationsInternet‐based sales provide an important adjunct to conventional retail sales and an important source of potential risk for landlords and tenants in the real estate investment market. Regardless of whether retailers use the internet as a sales channel, as a product‐sourcing tool, or merely to provide information to the consumer, the internet has become a keystone within the greater retail marketing mix. The findings have ramifications for understanding the way in which landlords are structuring their retail property to defray potential risks.Originality/valueThe paper examines shopping centre online marketing models for the first time in detail, and will be of value to retail occupiers, owners and other stakeholders of shopping centres.

In a search for potential acetylcholinesterase (AChE) inhibitors, the ethanol extract of the bulbs of Crinum X powellii (Amaryllidaceae) was found to demonstrate a marked inhibition of this enzyme. Using a bio-guided isolation strategy, linoleic acid ethyl ester has been identified as the compound responsible for this inhibition. Three other molecules - the alkaloid hippadine, the glycosylated benzyl alcohol derivative calleryanin and 4'-hydroxy-7-methoxyflavan - were also isolated and characterized for the first time from Crinum x powellii. The structures of these compounds were elucidated by spectrometric methods including EI, D/CI mass spectrometry, H-1, C-13 and 2D NMR experiments. Linoleic acid was also found to inhibit AChE.

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.

This paper is based on major survey of City of London occupiers conducted in the spring and summer of 2002 by The College of Estate Management, Reading. The aim of the research was to examine how eBusiness was driving process change amongst City office occupiers, and how this might change locational and space requirements in the future. This research shows how important information and communications technology (ICT) is becoming in driving process change for City office occupiers. However, ICT must be considered alongside forces for dispersal (for example, transport problems) and agglomeration (for example, face‐to‐face contact), which are creating a potent mix of factors driving businesses in the City. Changes in office densities, created by ICT and other drivers, have important implications for future office space projections in the City. The research shows that caution should be attached to the current office projections in the City provided in the Lord Mayor’s London Plan, and the results also have implications for continued investment in City offices. It is dangerous to over‐simplify density changes caused by ICT and other factors.

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.

LC-UV-MS analysis of the methanol extract of Jamesbrittenia fodina O. M. Hilliard (Scrophulariaceae) revealed the presence of cinnamic ester derivatives. Two isomeric pairs of these constituents were detected, but could not be isolated. In order to identify these unstable compounds, LC-H-1-NMR spectra were obtained for each individual isomer and standard NMR measurements were performed in-mixture. The spectra clearly demonstrated that the fractions consisted of mixtures of cis and trans cinnamoyl catalpol glycoside esters.

(2002). U.K. Retail Real Estate and the Effects of Online Shopping. Journal of Urban Technology: Vol. 9, No. 3, pp. 19-47.

Presents findings from separate research projects conducted in the UK and the USA on the impact of e‐commerce on retailers and retail property. Examines differences between UK and US retailers along several dimensions: Internet strategies, perceptions of the Internet, barriers to e‐commerce growth, and future space requirements. Overall, findings indicate that UK and US retailers have similar attitudes about e‐commerce. Specifically, retailers in both samples perceive little threat or impact from e‐commerce. Second, barriers to e‐commerce growth are similar for UK and US retailers and include fulfillment and security issues. Third, UK and US retailers indicate that their retail space needs will remain the same or increase in the short term, despite the threat of e‐commerce. Finally, both sets of retailers believe that entertainment is an important strategy if shopping centers are to remain viable.

Property ownership can tie up large amounts of capital and management energy that business could employ more productively elsewhere. Competitive pressures, accounting changes and increasingly sophisticated occupier requirements are building demand for new and innovative ways to satisfy corporate occupation needs. The investment climate is also changing. Falling interest rates and falling inflation can be expected to undermine returns from the traditional FRI lease. In future, investment returns will be more dependent on active and innovative management geared to the needs of occupiers on whom income depends. Occupier and investor interests, therefore, look set to coincide, but unlocking the potential for both parties will depend on developing new finance and investment vehicles that align their respective needs. In the UK, examples include PFI in the public sector and off‐balance sheet financing in the private sector. In the USA, “synthetic lease” structures have also become popular. Growing investment market experience in assessing risks and returns suggests scope for further innovative arrangements in the corporate sector. But how can such arrangements be structured? What are the risks, drivers and barriers?

Executive Summary. This article summarizes the main research findings from the first of a series of annual surveys conducted for the British Council of Shopping Centres. The study examines the chan...

Recent concerns over the valuation process in collective leasehold enfranchisement and lease extension cases have culminated in new legislation. To underpin this, the Government (Department of Environment Transport and the Regions (DETR)) commissioned new research, which examined whether the valuation of the freehold in such cases could be simplified through the prescription of either yield or marriage value/relativity. This paper, which is based on that research, examines whether it is possible or desirable to prescribe such factors in the valuation process. Market, settlement and Local Valuation Tribunal (LVT) decisions are analysed, and the basis of 'relativity charts' used in practice is critically examined. Ultimately the imperfect nature of the market in freehold investment sales and leasehold vacant possession sales means that recommendations must rest on an analysis of LVT data. New relativity curves are developed from this data and used in conjunction with an alternative approach to valuation yields (based on other investment assets). However, the paper concludes that although the prescription of yields and relativity is possible, it is not fully defensible because of problems in determining risk premia; that the evidential basis for relativity consists of LVT decisions; and that a formula approach would tend to 'lead' the market as a whole.

A total of 78 different extracts from 20 medicinal plants belonging to 14 plant families from Mali were tested for their antifungal, larvicidal, molluscicidal, antioxidant and radical scavenging activities. Dichloromethane, methanol, water and ethanol extracts were used. TLC autobiography for antifungal activity was run with Cladosporium cucumerinum and Candida albicans. Extracts were also tested on the larvae of the mosquitoes Aedes aegypti, Anopheles gambiae and Culex quinquefasciatus. Molluscicidal activities were established with the snails Biomphalaria glabrata, Biomphalaria pfeifferi and Bulinus truncatus. beta-Carotene and DPPH solutions sprayed on TLC plates were used for antioxidant and radical scavenging assays. Of the extracts investigated, 20% were antioxidant and radical scavengers, 19% fungicidal, 30% were larvicidal and 11% were molluscicidal. Three of the plant extracts, from Cussonia barteri (Araliaceae), Glinus oppositifolius (Aizoaceae) and Lannea velutina (Anacardiaceae) gave positive responses in all four tests.

Besides the known compounds longistylines C (1), D (2), and 3,5-dimethoxystilbene (5), five new prenylated stilbenes, named chiricanines A--E (3, 4, 6--8), have been isolated from the root bark of Lonchocarpus chiricanus. Their structures were resolved on the basis of spectrometric methods including (1)H, (13)C, and 2D NMR experiments and mass spectrometry. Compound 3 was the only prenylated stilbene to demonstrate antifungal effects against Cladosporium cucumerinum. Four of the isolated compounds showed toxic properties against larvae of the yellow fever-transmitting mosquito Aedes aegypti. Compound 5 was found to be as potent as rotenone in larvicidal dilution tests.

Two minor saponins obtained from the methanolic extract of the leaves of Ilex paraguariensis have been characterised by 13C-NMR, 1H-NMR, API-MS and chemical hydrolysis as oleanolic acid-3-O-(beta-D-glucopyranosyl-(1-->3)-alpha-L-arabinopyranosyl)-(28-->1)- beta-D-glucopyranosyl ester (guaiacin B) and oleanolic acid-3-O-(beta-D-glucopyranosyl-(1-->3)-(alpha-L-rhamnopyranosyl- (1-->2))-alpha-L-arabinopyranosyl)-(28-->1)-beta-D-glucopyranosyl ester (nudicaucin C). Both are isomeric forms of the known matesaponins 1 (MSP 1) and 2 (MSP 2) and differ only by the nature of the aglycone: they have oleanolic acid instead of ursolic acid, as found in the matesaponins. These minor saponins have not been fully separated from their major isomers MSP 1 and 2 and were characterised by in-mixture NMR analysis, LC-MS and LC-MSn experiments.

African plants have long been the source of important products with nutritional and therapeutical value. Coffee originates from Ethiopia, Strophanthus species are strong arrow poisons and supply cardenolides for use against cardiac insufficiency, the Catharanthus roseus alkaloids are well-known antileukaemic agents - just to mention a few examples. Research is continuing on the vegetable material from this continent in an endeavour to find new compounds of therapeutic interest. An outline is presented here covering the results obtained by the Institute of Pharmacognosy and Phytochemistry of the University of Lausanne during 15 years' work on African plants. The strategy employed for the study of these plants is outlined, covering all aspects from the selection of plant material to the isolation of pure natural products. Different bioactivities have been investigated: the search for new antifungal, molluscicidal and larvicidal agents has been the most important axis. Results are also included for antibacterial, cytotoxicity, anti-inflammatory testing

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.

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.

Purpose. Terminalia macropteraroots are used in Guinea-Bissau and other West African countries to treat infectious diseases like gonorrhoea. Previous work showed an ethanol extract of T. macroptera roots (T) to have an in vitro antimicrobial profile against Neisseria gonorrhoae (including resistant strains) and enteropathogenic agents. The most active fractions of this extract were identified as the diethyl ether (T2) and water (T5) fractions. The aim of the present study was the identification of major compounds present in T and simultaneously in T2 or T5.

Eight xanthones and a biphenyl have been isolated from the dichloromethane extract ofKielmeyera coriacea (Guttiferae) stem bark by a combination of centrifugal partition chromatography and gel filtration on Sephadex LH-20, with HPLC-UV monitoring of fractions. The structures of the isolated compounds (Figure 1) were established by spectroscopic methods (UV, EI-MS, D/CI-MS,1H NMR,13C NMR).

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.

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.

Analysis of the dichloromethane extracts of Kielmeyera coriacea leaves and stems by high performance liquid chromatography coupled with a photodiode array detector (LC-UV) and thermospray liquid chromatography-mass spectrometry (TSP/LC-MS) revealed the presence of several xanthones. Phytochemical investigation of these extracts resulted in the isolation and identification of ten xanthones, one biphenyl and two triterpenes. Their structures were established by chemical and spectroscopic methods (UV, EI-MS, D/CI-MS, 1 H NMR, 13 C NMR, HMQC and HMBC). One xanthone and two triterpenes are new compounds. Four xanthones and the biphenyl exhibited antifungal activity against the plant pathogenic fungus Cladosporium cucumerinum , while two prenylated xanthones inhibited the growth of Candida albicans .

This paper describes the versatile operation of CCC, its potential for scale up and compares its operational performance with HPLC as a generic preparative purification process. In the words of the UK Biology & Biotechnology Science Research Council (BBSRC), there is a need for a “generation of new, robust, and usable techniques for bioprocess intensification and simplification” and, in particular, technology that can be scaled from laboratory to process scale easily and cheaply without any fundamental change to the principle of separation. CCC offers the potential to do this.

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.

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.

The chromonocoumarins frutinones A and B and lignans eudesmin, magnolin, yangambin and kobusin were isolated from lipophilic extract of P. gazensis. This species and two other related Polygala species were subsequently analysed by thermospray liquid chromatography–mass spectrometry and high pressure liquid chromatography coupled with photodiode-array detection. Frutinone A was also found in the roots and aerial parts of P. teretifolia and P. fruticosa, while the presence of frutinone B was limited principally to the roots. Lignans were present in the aerial parts of P. teretifolia. Frutinone A showed antifungal activity against Cladosporium cucumerinum and Candida albicans while eudesmin and kobusin were antifungal against Cladosporium cucumerinum only. © 1997 by John Wiley & Sons, Ltd.

Coumarins are a large group of naturally-occurring compounds with a wide range of biological properties, including anticancer activity. 7-Substituted coumarins (umbelliferone, scoparone, and herniarin) were analyzed for their potential anticancer activity against laryngeal cancer cells (LCC).High-performance counter-current chromatography was applied for successful separation of umbelliferone from fruits of Heracleum leskowii. A two-phase solvent system composed of n-heptane-methanol-ethyl acetate-water (1:2:1:2, v/v/v) was successfully used. Cell proliferation was assessed after 48-72 h by means of MTT test, and tumor cell motility by a wound assay model. Measurement of cell death was estimated using enzyme-linked immunosorbent assay (ELISA), and cell-cycle analysis was performed by flow cytometry. Extracellular signal-regulated kinases-1/2 (ERK1/2) and AKT kinase activation status were analyzed by western blotting.Umbelliferone, scoparone, and, to a lesser extent, herniarin reduced viability and migration of RK33 LCC in a dose-dependent manner. Scoparone and herniarin were found to induce apoptosis of LCC. None of the tested compounds influenced the ERK1/2 and AKT kinase activity, nor significantly affected cell-cycle progression in the LCC line studied.Our findings suggest the therapeutic potential of 7-substituted coumarins in the treatment of laryngeal cancer.