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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.

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.

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 .

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.

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.

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.

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.

A new gamma-pyrone (hyperbrasilone), three known xanthones (1,5-dihydroxyxanthone, 5-hydroxy-1-methoxyxanthone and 6-deoxyjacareubin) and betulinic acid have been isolated from a dichloromethane extract of stems and roots of Hypericum brasiliense. Their structures were established by spectroscopic methods (UV, EI-MS, 1H and 13C NMR) and that of the gamma-pyrone was confirmed by X-ray crystallography. Hyperbrasilone and the xanthones were all antifungal against Cladosporium cucumerinum, while the three xanthones showed differing degrees of inhibition of monoamine oxidase A and B.

From the latex of Euphorbia milii var. hislopii collected in Brazil, eight milliamines were isolated using a bioassay-guided protocol based on molluscicidal activity. Three were known milliamines A, D and E, the other five being new compounds of this class. Milliamine L, a dianthraniloyl peptide ester of ingenol, was found to be molluscicidal at 4 nM (2.5 μg 1 −1 ).

The dichloromethane extract from the roots of Polygala nyikensis afforded four simple xanthones, two of which are new compounds. Their structures were established by chemical and spectroscopic methods (UV, EIMS, 1 H and 13 C NMR, NOE difference spectroscopy). 1,7-Dihydroxy-4-methoxyxanthone and 1,7-dihydroxy-3,5,6-trimethoxyxanthone exhibit antifungal activity against the plant pathogenic fungus Cladosporium cucumerinum .

Chromatography is the lynchpin of phytochemistry and is the key to obtaining pure compounds for structure elucidation, for pharmacological testing or for development into therapeuticals. It also plays a fundamental role as an analytical technique for quality control and standardisation of phytotherapeuticals. Although liquid chromatography is barely 100 years old, an extraordinary variety of instrumental and ancillary equipment is available, notably in the domain of high-performance liquid chromatography. It is impossible to touch all areas of chromatography in such a review but certain areas are worthy of mention: HPLC, HPTLC, UPLC and countercurrent chromatography. Another important addition has been the development of hyphenated techniques involving HPLC: LC/UV, LC/MS, LC/MS(n) and LC/NMR. These are indispensable nowadays for the early detection and identification of compounds in crude plant extracts.

Two new diterpenes, fusicoserperiol A and dolabeserpenoic acid A, with antifungal activity, were isolated from leaves of Hypoestes serpens (Acanthaceae). Their structures were elucidated by means of spectrometric methods including ID and 2D NMR experiments and MS analysis. X-ray crystallographic analysis confirmed the structure of fusicoserpenol A and established the relative configuration. (C) 2003 Elsevier Science Ltd. All rights reserved.

Three new xanthone glycosides have been isolated from Halenia campanulata . They were identified as 2,3,5-trimethoxy- 1- O -gentiobiosyloxyxanthone, 2,3,5-trimethoxy-1- O -primeverosyloxyxanthone and 2,3,4,5-tetramethoxy-1- O - primeverosyloxyxanthone. Their corresponding aglycones were also isolated from the plant, together with the secoiridoid glycosides vogeloside and epi -vogeloside.

A new phenolic glycoside was isolated from Hypoxis obtusa, together with the known compounds acuminoside, hypoxoside and nyasoside. In the new glycoside, 2,5-dihydroxybenzyl alcohol and 3-hydroxy-2,6- dimethoxybenzoic acid moieties are linked to glucose at the C-1 and C-6 positions respectively.

Three new meroterpenoid naphthoquinones, the known cordiaquinone B and a new naphthoxirene have been isolated from the roots of Cordia linnaei. Their structures were established by spectrometric methods including EI, D/CI and FAB mass spectrometry, 1H, 13C and 2D NMR experiments. The naphthoquinones showed activity against Cladosporium cucumerinum, Candida albicans and the larvae of the yellow fever-transmitting mosquito Aedes aegypti, while the naphthoxirene derivative was found to be inactive in the same bioassays.

A review on the application of plant molluscicides in the control of schistosomiasis is presented. Laboratory bioassays are discussed, together with criteria for activity. An attempt has been made to provide a comprehensive list of known molluscicidal natural products.

Three saponins with molluseicidal and fungicidal activities have been isolated from the roots of Dolichos kilimandscharicus . They were shown to be the 3- O -β- d -glucopyranosides of hederagenin, bayogenin and medicagenic acid.

The rotenoids deguelin and tephrosin were isolated from leaves of Tephrosia vogelii, together with three flavonol glycosides, rutin, isoquercitrin and quercetin 3-O-arabinoside. Although T. vogelii leaves are reportedly toxic to aquatic snails, deguelin and tephrosin were found to have no significant molluscicidal activity.