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An antiplasmodial activity-guided isolation was carried out on the dichloromethane extract of Tithonia diversifolia dried leaves. A total of five germacranolide type sesquiterpene lactones and a new flavonol, 3,6-dihydroxy-2-(4′-hydroxyphenyl)-7-methoxy-4H-chromen-4-one, were isolated. The flavonol reported an IC50 above 6.00 µM against the chloroquine sensitive strain, NF54. The antimalarial activity of the Tithonia diversifolia dichloromethane leaf extract was attributed to orizabin and tagitinin C.

In this study, three new germacranolide sesquiterpenes (1-3), together with six related known analogues (4-9) were isolated from the whole plant of Carpesium cernuum. Their structures were established by a combination of extensive NMR spectroscopic analysis, HR-ESIMS data, and ECD calculations. The anti-leukemia activities of all compounds towards three cell lines (HEL, KG-1a, and K562) were evaluated in vitro. Compounds 1-3 exhibited moderate cytotoxicity with IC50 values ranging from 1.59 to 5.47 μmol·L-1. Mechanistic studies indicated that 2 induced apoptosis by decreasing anti-apoptotic protein Bcl-2 and activating the caspase family in K562 cells. These results suggest that compound 2 is a potential anti-leukemia agent.

Background: The parasitic protozoal infections leishmaniasis, human African trypanosomiasis, and Chagas disease are neglected tropical diseases that pose serious health risks for much of the world’s population. Current treatment options suffer from limitations, but plantderived natural products may provide economically advantageous therapeutic alternatives. Several germacranolide sesquiterpenoids have shown promising antiparasitic activities, but the mechanisms of activity have not been clearly established. Objective: The objective is to use in silico screening of known antiparasitic germacranolides against recognized protozoal protein targets in order to provide insight into the molecular mechanisms of activity of these natural products. Methods: Conformational analyses of the germacranolides were carried out using density functional theory, followed by molecular docking. A total of 88 Leishmania protein structures, 86 T. brucei protein structures, and 50 T. cruzi protein structures were screened against 27 antiparasitic germacranolides. Results: The in-silico screening has revealed which of the protein targets of Leishmania spp., Trypanosoma brucei, and Trypanosoma cruzi are preferred by the sesquiterpenoid ligands.

Three undescribed germacranolide sesquiterpene lactones, named macrocephalides A-C, along with known steroids, triterpenes and flavonoids were isolated from the aerial parts of Campuloclinium macrocephalum. The structures of the undescribed compounds were elucidated with basis on their 1D and 2D-NMR, and HR-ESI-MS data. Their absolute configurations were assigned by comparison of experimental and calculated electronic circular dichroism (ECD) spectra. Additionally, macrocephalides A-C were evaluated for their in vitro cytotoxic activities against nine human cancer cell lines. Macrocephalides A and B exhibited moderate to potent cytotoxic activity, inhibiting 50% of cell growth (GI50) at concentrations ranging from 0.576 to 6.37 μM.

Carpesium humile Winkl is an endemic Chinese species and no previous phytochemical studies have been reported for this species. Two new germacranolides (1 and 2) and a new phytane diterpene (5), together with five known compounds (two sesquiterpenoids and three diterpenoids), were isolated from the aerial parts of C. humile. Their structures were elucidated on the basis of extensive spectroscopic analysis. The conformations and absolute configurations of 1 and 2 were established by combinative analysis of NMR, CD exciton chirality, and X-ray crystallography data. Four germacranolides (1–4) showed strong cytotoxic activities, with broad spectrum activities against six human cancer (HepG2, HeLa, HL60, SGC7901, Lewis, and MDA231) cell lines in vitro using MTT assay, with IC50 values from 3.09 to 7.71 μg/mL. Diterpenes (5, 6, and 8) also displayed good cytotoxic activities for selected cancer cell lines, with IC50 values in the range 5.46–8.08 μg/mL.

An unusual adenine-substituted germacrane sesquiterpene lactone, tomenphantadenine (1), has been isolated from the whole plant of Elephantopus tomentosus L. The structure of this compound was established by comprehensive spectroscopic analysis including high resolution (HR) ESI-MS, 1D and 2D nuclear magnetic resonance (NMR) spectroscopic data. This compound features novel hybrid pattern of germacrane sesquiterpene with adenine through C-N linkage, and a possible biosynthetic pathway for it was proposed. Compound 1 showed potent antibacterial activity against the gram-positive Staphylococcus aureus and weak acetylcholinesterase (AChE) inhibitory activity.

The antibacterial profiling of Onopordum acanthium L. leaf extract and subsequent targeted identification of active compounds is demonstrated. Thin-layer chromatography (TLC) and off-line overpressured layer chromatography (OPLC) coupled with direct bioautography were utilized for investigation of the extract against eight bacterial strains including two plant and three human pathogens and a soil, a marine and a probiotic human gut bacteria. Antibacterial fractions obtaining infusion-transfusion OPLC were transferred to HPLC–MS/MS analysis that resulted in the characterization of three active compounds and two of them were identified as, linoleic and linolenic acid. OPLC method was adopted to preparative-scale flash chromatography for the isolation of the third active compound, which was identified after a further semi-preparative HPLC purification as the germacranolide sesquiterpene lactone onopordopicrin. Pure onopordopicrin exhibited antibacterial activity that was specified as minimal inhibitory concentration in the liquid phase as well.

Three new elemanolides, named vernonilides D (1), E (2), and F (3), along with four known sesquiterpenoids, including two elemanolides (4, 5), a guaianolide (6), and a germacranolide (7) were isolated from the seeds of Vernonia anthelmintica. The structures of them were elucidated based on 1D and 2D NMR experiments and comparison with published data. Cytotoxicity of the compounds against four human tumor cell lines was assayed. 6 showed strongly inhibitory effect against HCT-15 and PC-3 cell lines with IC50 values of 0.56 and 0.69 μM, respectively. The new compounds showed moderate cytotoxicity against four cell lines with IC50 values ranging from 9.1 to 28.1 μM.

Repeated chromatographic purifications of aerial parts of the Tunisian plant Daucus virgatus led to the isolation of four new germacranolides, named daucovirgolides I-L (2-5), along with the Plasmodium transmission-blocking agent daucovirgolide G. The chemical structures of the new compounds were defined as mono- or di-angeloylated germacrane-type sesquiterpenoids by spectroscopic (mainly 1D and 2D NMR) and spectrometric methods (ESIMS). The low potency exhibited by daucovirgolides I-L further supports the observation that strict structural requirements do exist for the Plasmodium transmission blocking activity in the daucovirgolide series. In particular, the endocyclic double bond system seems to be crucial for bioactivity.

The Alpine wormwood Artemisia vallesiaca All. was considered the most valuable ingredient of vermouth, a celebrated aromatized wine. A. vallesiaca has a very limited geographical distribution, and the booming market of vermouth decimated its natural population, resulting in the eventual replacement of this rare species with more common and less expensive wormwoods like A. absinthium L.. Over the past years, attempts to revive the original recipe(s) of vermouth have fostered the establishment of cultivations of A. vallesiaca in pre-montane settings. In order to assist these projects, the phytochemical profile of cultivated plants and of several native populations of A. vallesiaca from the Swiss Valais were comparatively evaluated, focusing on sesquiterpene lactones and on lipophilic flavonoids, the hallmark constituents of Artemisia species. Remarkably, no significant difference was detected between the samples, despite the different origins. The lipophilic flavonoids of A. vallesiaca were similar to those of related species used in the production of vermouth, but the presence of C-9 oxygenated 11β-methyl germacranolides and eudesmanolides (herbolides) made its sesquiterpene lactone profile peculiar. In addition to known compounds, two novel germacranolides were also characterized (herbolides J and K), and the major sesquiterpene lactone from the plant, the bitter germacranolide herbolide D (4), was detected and quantified by 1H NMR in a bitter liqueur aromatized with A. vallesiaca. Taken together, these observations qualify herbolides as marker to identify A. vallesiaca in aromatized alcohol matrixes.

The germacranolide 1-epi-tatridin B has been isolated from the aerial parts of Laurus novocanariensis. We have observed that the identification of this lactone and its epimer tetradin B in the scientific literature is confusing and contradictory. We have therefore studied this issue clarifying errors and contributing to the structural elucidation of other related products. Moreover, we have isolated from this plant a lactone with an 1,5-ether bridge, previously obtained from Austrolabium candidum. We have now named it austroliolide, reassigned its C NMR spectrum and compared its structure with that of badgerin. In addition, we have also isolated from L. novocanariensis the known germacranolides artemorin, costunolide, tatridin A, tulirinol and verlotorin, the eudesmanolides β-cyclopyrethrosin, 1β-hydroxy-arbusculin A, magnoliaolide and reynosin, and the guaianolide dehydrocostus lactone., This work has been supported by grants CTQ2012-38219-C03-01 and CTQ2015-64049-C3-1R, MINECO, Spain.

A heme-binding assay based on mass spectrometry was performed on P. monodiana Maire (Asteraceae) extracts to identify metabolites able to form adducts with heminic part of haemoglobin, as potential antimalarial drugs. Main adducts were characterized and their stability was measured. Isolation of main constituents of P. monodiana Maire lead to identification of the two methoxyflavones 3'-O-methyleupatorin (7) and artemetin (8) involved in the adducts formation. Four seco-tanapartholides (1-4), a guaianolide (5), a germacranolide (6) and two other methoxyflavones (9, 10) were also characterized. Evaluation of isolated compounds on P. falciparum and T. brucei brucei showed a moderate antiprotozoal activity of the two methoxyflavones.

The non polar extract of Centaurea pannonica (Heuff.) Simonk., growing wild in Serbia, was studied and twenty-five compounds including 14 sesquiterpene lactones, 7 flavonoids, 3 lignans and 1 phenylpropanoid glycoside were isolated. All compounds were isolated for the first time from this species. Among them, one germacranolide 2α-hydroxy, 8-dehydroxy 15-O-methacrylate salonitenolide (1) and two guaianolides 2α,8α-dihydroxy-dehydrocostus lactone (2) and pannonin (3) are new natural compounds. The structures of the compounds were established on the basis of spectroscopic analyses (UV, IR, HREIMS and 1D & 2D NMR). The chemical profile of C. pannonica, which belongs to the “Centaurea jacea” group, was compared to previously studied taxa of the same group and used to assess the phylogenetic relationships in the group.

Ambrosia artemisiifolia L. (common ragweed) is an invasive plant whose allelopathic properties have been suggested by its field behaviour and demonstrated through phytotoxicity bioassays. However, the nature of the molecules responsible for the allelopathic activity of common ragweed has not been explored. The main objective of this study was to identify the phytotoxic molecules produced by A. artemisiifolia. A preliminary investigation has indicated that a methanol extract of A. artemisiifolia completely inhibited the germination of cress and radish. Semi-preparative fractionation of the methanol extract allowed separating of phytotoxic fraction which contained a single compound. The structure of this compound was elucidated by liquid chromatography–mass spectrometry (LC-MS)/MS, high-resolution mass spectral, nuclear magnetic resonance, and Fourier transform infrared spectra as sesquiterpene lactone isabelin (C15H16O4). The effect of pure isabelin was tested on four different weed species, confir...

Six new germacranolides, zawadskinolides A-F (1-6), and a new eudesmane glucoside, chrysantiloboside (7) were isolated from the aerial parts of Dendranthema zawadskii var. latilobum, along with thirteen known constituents. Their structures were elucidated by means of spectroscopic evidence. Bioassay showed that flavonoids such as apigenin (9), (-)-eriodictyol (10) and nepetin (12), as well as the sesquiterpene lactone, zawadskinolide F (6), inhibited nitric oxide (NO) production in lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophage cells with IC50 values of 66.15, 132.55, 35.44, and 91.32 μM, respectively.

The CH(2)Cl(2) extract of aerial parts of Eupatorium perfoliatum L. exhibits antiprotozoal activity under in vitro conditions, especially against Plasmodium falciparum (IC(50)=2.7mug/ml). The search for active compounds yielded seven sesquiterpene lactones: Four structurally similar guaianolides, one dimeric guaianolide, and two germacranolides. The guaianolides differ in the degree of oxidation at C-14, ranging from a hydroxyl group up to a free carboxylic acid. The dimeric guaianolide, structurally closely related to the monomers, displays an unusual type of interguaianolide linkage between C-14 and C-4. Except for the germacranolide euperfolitin, all STLs described here were hitherto unknown. Furthermore, the flavonoid aglycones eupafolin, hispidulin, patuletin, and kaempferol were identified in the extract, which, except for kaempferol, have not been described as constituents of E. perfoliatum before. The dimeric guaianolide was shown to be the most active constituent against Plasmodium falciparum (IC(50) = 2.0muM) and was less cytotoxic against rat skeletal myoblasts (IC(50) = 16.2muM, selectivity index of about 8)

Some sesquiterpene lactones (SLs) are the active compounds of a great number of traditionally medicinal plants from the Asteraceae family and possess considerable cytotoxic activity. Several studies in vitro have shown the inhibitory activity against cells derived from human carcinoma of the nasopharynx (KB). Chemical studies showed that the cytotoxic activity is due to the reaction of alpha,beta-unsaturated carbonyl structures of the SLs with thiols, such as cysteine. These studies support the view that SLs inhibit tumour growth by selective alkylation of growth-regulatory biological macromolecules, such as key enzymes, which control cell division, thereby inhibiting a variety of cellular functions, which directs the cells into apoptosis. In this study we investigated a set of 55 different sesquiterpene lactones, represented by 5 skeletons (22 germacranolides, 6 elemanolides, 2 eudesmanolides, 16 guaianolides and nor-derivatives and 9 pseudoguaianolides), in respect to their cytotoxic properties. The experimental results and 3D molecular descriptors were submitted to Kohonen self-organizing map (SOM) to classify (training set) and predict (test set) the cytotoxic activity. From the obtained results, it was concluded that only the geometrical descriptors showed satisfactory values. The Kohonen map obtained after training set using 25 geometrical descriptors shows a very significant match, mainly among the inactive compounds (approximately 84%). Analyzing both groups, the percentage seen is high (83%). The test set shows the highest match, where 89% of the substances had their cytotoxic activity correctly predicted. From these results, important properties for the inhibition potency are discussed for the whole dataset and for subsets of the different structural skeletons.

A preparative high-speed counter-current chromatography (HSCCC) method for isolation and purification of costunolide and dehydrocostuslactone from the Chinese medicinal plant Aucklandia lappa Decne (Muxiang in Chinese) was successfully established by using light petroleum-methanol-water (5:6.5:3.5, v/v/v) as the two-phase solvent system. The upper phase of light petroleum-methanol-water (5:6.5:3.5, v/v/v) was used as the stationary phase of HSCCC. 35.7 mg of costunolide and 43.6 mg of dehydrocostuslactone with the purity of 100% and 99.6%, respectively, were separated successfully in one-step separation from 110 mg of crude sample from Aucklandia lappa Decne. The structures of costunolide and dehydrocostuslactone were identified by 1H NMR and 13C NMR.

The effects of germacranolides isolated from Calea urticifolia on adipocytic differentiation of 3T3-L1 cells were examined. These germacranolides inhibited adipogenesis at a concentration of 1.25-5 microM. But no inhibitory activity against cell proliferation and no nonspecific binding activity to protein were observed. These results indicate that these germacranolides are the specific inhibitors of preadipocyte differentiation.

The aerial parts of Anvillea radiata yielded a new germacranolide, 8α,9α-epoxyparthenolide ( 3 ), together with two known compounds, 9α-hydroxyparthenolide ( 1 ) and parthenolid-9-one ( 2 ). The structures of the compounds were elucidated from IR, HRMS, 1 H and 13 C-NMR, COSY, HETCOR, HMBC and HOHAHA spectral data. The major component 1 was tested for its cytotoxicity and antibacterial activity.

The aerial parts of Inula verbascifolia afforded two new xanthanes and a new germacranolide derivative, together with the known compounds inusoniolide, 4-O-dihydroinusoniolide and 9β-hydroxyparthenolide. The structures were determined by spectral methods (IR, HRMS,1H NMR, 13C NMR, DEPT, 1H–1H COSY, HMQC and HMBC).

The CH(2)Cl(2) extract of the aerial parts of Artemisia myriantha afforded three germacranolides derived from 13-acetoxy-3beta-hydroxy-germacra-1(10)E,4E,7(11)-trien-12,6alpha-olide, whose structures were elucidated by 2D-NMR spectroscopic analyses. Some conclusions are drawn about the possible conformations of the ten-membered germacranolide ring system from the exchange peaks seen in the NOESY spectra, and an estimate is made of the energy barrier to ring-flipping from variable-temperature NOESY experiments. The conclusions reached were supported by molecular modeling studies and an NMR spectroscopic investigation of the commercially available germacranolide, parthenolide.

Four new germacrane-type sesquiterpenoids with unsaturated acids as esters at the 8-position, two chlorine atom-containing lactones, 2alpha-acetoxyepitulipinolide, and 12 previously known compounds have been isolated from the MeOH extract of Eupatorium glehni (Compositae) and their structures have been determined on the basis of spectral data analyses.

The methanol extract of sub-aerial parts of Hieracium murorum L. gave germacra-7αH-1(10)E,4Z,11­(13)-trien-12,8α-olide-15-oic acid (15 1)-β-D-glucopyranosyl ester (1), a new sesquiterpenoid of the germacrane-type, and two new 4-hydroxybenzyl alcohol derivatives, 4-hydroxy-cinnamomic acid 4-β-D-glucopyranosyloxybenzyl ester (2) and 3-hydroxy-2-[(4-hydroxy-phenyl)-acetoxy]-3-methyl-butyric 4-β-D-glucopyranosyloxybenzyl ester (3). The methanol extract of sub-aerial parts of Crepis bocconi P. D. Sell gave 4-hydroxybenzoic acid 4-β-D-glucopyranosyloxybenzyl ester (4), another new 4-hydroxybenzyl alcohol derivative. The structures of these compounds were established by means of MS and one- and two dimensional-NMR experiments. Copyright © 2001 John Wiley & Sons, Ltd.

The aerial parts of Centaurea thessala ssp. drakiensis and C. attica ssp. attica afforded, in addition to several known sesquiterpene lactones, two new eudesmanolides, 4-epi-sonchucarpolide and its 8-(3-hydroxy-4-acetoxy-2-methylene-butanoyloxy) derivative and one new eudesmane derivative, named atticin. The in vitro antifungal activity of most compounds was tested against nine fungal species, using the micro-dilution method. All the compounds tested showed great antifungal activity.

From the roots of Crepis mollis, one new and two known guaianolides were isolated together with eight known guaianolide glycosides, one known germacranolide glycoside and two known phenylpropanoids. The structure and relative configuration of the new compound were established as 9alpha-hydroxy-4beta, 15, 11beta, 13-tetrahydro-dehydrozaluzanin C by spectral methods.

Fungicidal activity of 36 natural and synthetic sesquiterpene lactones with guaianolide, trans, trans-germacranolide, cis, cis-germacranolide, melampolide, and eudesmanolide carbon skeletons was evaluated against the phytopathogenic fungi Colletotrichum acutatum, C. fragariae, C. gloeosporioides, Fusarium oxysporum, Botrytis cinerea, and Phomopsis sp. Dose-response data for the active compounds dehydrozaluzanin C, dehydrocostuslactone, 5alpha-hydroxydehydrocostuslacone, costunolide, and zaluzanin C are presented. A new 96-well microbioassay procedure for fast and easy evaluation of antifungal activity was used to compare these compounds with commercial fungicide standards. Some structure-activity conclusions are also presented.

The new germacranolide epi -isocostunolide and two new bisbibenzyls, 2′-(11-hydroxy-1-bibenzyl-oxy)-1′-methoxy-6′,10′,11′-trihydroxy-7′,8′-dihydro-phenanthrene and 2′-(10,11-dihydroxy-1-bibenzyl-oxy)-1′-methoxy-6′,10′,11′-trihydroxy-7′,8′-dihydrophenanthrene, along with the known eudesmanolides, α-cyclocostunolide, brothenolide, nepalensolide A and nepalensolide B, the bisbibenzyls, perrottetin E, perrottetin F, perrottetin G, 7′,8′-dehydroperrottetin F, and the bibenzyls, lunularic acid and lunularin, have been isolated from the neotropical liverwort Frullania convoluta . Their structures were elucidated by NMR spectroscopy.

Microbial transformation of the germacranolide parthenolide using Rhizopus nigricans , Streptomyces fulvissimus and Rhodotorula rubra yielded three new compounds: 11αH-dihydroparthenolide, 9β-hydroxy-11βH-dihydroparthenolide and 14-hydroxy-11βH-dihydroparthenolide. 11βH-dihydroparthenolide was the only common metabolite produced by all microorganisms.

The aerial parts of Stevia alpina var. glutinosa afforded, in addition to knownsesquiterpene lactones, two new germacranolides and two new eudesmanolides. The structureswere established mainly by NMR spectroscopy.

Two new neurolenin-type sesquiterpene lactones were found in the leaves of Neurolaena macrocephala Sch. Bip. Ex Hemsl. ( Asteraceae ). These compounds were identified by their NMR spectra as the 8 β -isobutyryloxy- and 8 β - (2-methyl)butyryloxy analogs of neurolenin B. Additionally, the known neurolenins B, C and D and the furanoheliangolide 9a-acetoxy-8 β -isovaleryloxy-calyculatolide were found to be present in this species.

A new germacranolide, inulacappolide (1), was isolated from the EtOH extract of the whole plant of Inula cappa along with 16 known compounds. The structure of inulacappolide was a rare 1(10)-saturated type of germacran-6,12-olide, identified as 2alpha-acetoxy-3beta-hydroxy-9beta-angeloyloxygermacra-4-en-6alpha,12-olide by spectral analysis (IR, HR-ESI/MS, (1)H-NMR, (13)C-NMR, HMQC, HMBC, NOESY). In vitro, it showed antiproliferative effects against human cervical cancer HeLa, human leukemia K562 and human nasopharyngeal carcinoma KB cell lines with IC(50) values of 1.2 microM, 3.8 microM and 5.3 microM, respectively.

In addition to known compounds, the aerial parts of Podachaenium eminens contained the guaianolide named eminensin A, the eudesmanolide eminensin B and podachaenin, a compound formed through esterification of an hydroxyguaianolide by costic acid. Structures of these compounds were established by analysis of their spectroscopic data and, in the case of eminensin A, it was confirmed by X-ray crystallographic analysis.

The minimum inhibitory concentrations (MIC) against Mycobacteriumtuberculosis and M. avium of parthenolide, costunolide, 1 (10)-epoxycostunolide and other germacranolide-type sesquiterpene lactones and derivatives were determined by use of a radiorespirometric bioassay. Structure-activity relationship studies with natural and semisynthetic sesquiterpene lactones suggested that the α -methylene- γ -lactone moiety is an essential, but not sufficient, structural requirement for significant in vitro activity against M. tuberculosis and M. avium .

The aerial parts of Vicoa indica afforded a new sesquiterpene lactone as its acetate (1) the structure and relative stereochemistry of which was established by spectral data including X-ray crystallographic analysis.

The investigation of two Onopordon species afforded, in addition to known sesquiterpene lactones and other constituents, six new germacranolides and a new eudesmanolide. The structures were elucidated by spectroscopic methods.

An extract of whole plants of Achillea santolina afforded a new guaianolide and a new germacranolide in addition to two known guaianolides and three flavonoids. Structures were elucidated by spectroscopic methods, and the structure of the germacranolide was confirmed by a single crystal X-ray analysis.

The aerial parts of Artemisia inculta collected in three different locations in Egypt have been chemically investigated. As a result, a new eudesmanolide and a new tetranorsesquiterpene lactone have been isolated, together with several known compounds. The chemical data available suggest the existence of distinct chemotypes for this species, but do not support its identity with other North African members of the genus.

The aerial parts of Artemisia lucentica yielded, in addition to several known compounds, a bicyclic monoterpene ketone, two germacranolides, an eudesmanolide, a 10- epi neudesmanolide, a 2-norelemanolide and three bisabolene derivatives. The stereochemistry of a germacranolide, described as 2α-hydroxyartemorin in a previous investigation of the species, has now been corrected and the compound has been renamed lucentolide.

An extract of whole plants of Urospermum picroides afforded five new germacronolides and germacranolide glycosides. Their structures were elucidated by spectroscopic methods.

From the roots of Lactuca tatarica, one new and two known guaianolides were isolated together with five known guaianolide glycosides, three known germacrolide glycosides and benzyl-β-glucopyranoside. The structure of the new compound was elucidated as 11βH, 13-dihydrolactucin-8-O-p-methoxyphenylacetate by spectral methods.

The whole plant of Elephantopus scaber afforded the known deoxyelephantopin and isodeoxy-elephantopin, and a new germacranolide sesquiterpene lactone named scabertopin, whose structure and stereo-chemistry were determined by spectroscopic methods and single-crystal X-ray analysis.

Three new eudesmenoic acid methyl esters (1-3), as well as five known compounds, including three germacranolides (4-6) and two eudesmanolides (7 and 8), were isolated from the seed oil of Jatropha curcas. The new compounds were elucidated by means of spectroscopic methods, including extensive NMR spectra. In addition, the structure of 8 was confirmed by a single-crystal X-ray diffraction analysis. Among the isolates, compounds 4-6 were the first reported from the genus Jatropha. Using MTS viability assay, the cytotoxicity of compounds 2-8 were evaluated against HL-60, SMMC-7721, A-549, MCF-7, and SW480 human tumor cell lines. Compounds 4 and 5 showed remarkable cytotoxicity against all the tested cell lines with IC50 values from 0.5 to 3.5 mu M, and the new compound 3 displayed selective cytotoxic activity against A-549 cell with an IC50 value of 7.24 mu M, but slight cytotoxicity against HL-60 and MCF-7 with IC50 values of 23.77 and 22.37 mu M, respectively. (C) 2013 Elsevier B.V. All rights reserved.

Isolation, structure elucidation and allelopathic bioassays of 13 sesquiterpene lactones, four of them new, from the sunflower cultivar VYP® are described. Structures of the lactone assigned as 1,2-anhydrido-4,5-dihydroniveusin A, previously isolated from capitate glandular trichomes of Helianthus annuus and of annuithrin are corrected. The effect of a series of aqueous solutions at 10−4–10−9 M of the sesquiterpene lactones was studied on the root and shoot lengths of Lactuca sativa var. nigra, Lepidium sativum, Lycopersicon esculentum, seedlings (dicotyledons) and Hordeum vulgare and Triticum estivum (monocotyledons). The guaianolides generally had no effect on the germination and growth of L. sativum and L. esculentum, except for C-10 epimers 8β-angeloyloxycumambranolide and annoulide G where inhibitory effects were found on the shoot length of L. esculentum. Both exhibit similar activity profiles, the most persistenty active compound on dilution was 8β-angeloyloxycumambranolide with an α-orientated hydroxyl group at C-10. The conformational changes due to functionalization within germacranolides influence principally root and shoot growth. Heliangolides have greater effect on root and shoot length of dicotyledon species, presumably due to conformational flexibility and the presence of electrophylic groups.

The aerial parts of Stevia vaga afforded four new guaianolides, four new germacranolides, one new melampolide and three new heliangolides as well as two known flavones. The structures were established mainly by NMR spectroscopy.

Aerial parts of Stevia maimarensis afforded two known and six new germacradienolides as well as one known and two new eudesmanolides. Aerial parts of Synedrellopsis grisebachii furnished only previously known compounds and no sesquiterpene lactones.

An extract of the aerial parts of Inula salsoloides afforded in addition to known compounds an eudesmanolide, two melampolides and two linear sesquiterpenes. The structures and spectroscopic data of two germacranolides are revised

Investigation of the aerial parts of Mikania mendocina yielded, in addition to known quadrangolide, two new 15-norguaianolides, a new guaianolide and three new germacranolides. The structure of a germacranolide isolated from M. dusenii has been revised.

Aerial parts of Mikania ypacarayensis afforded, in addition to mikanolide and related known sesquiterpene dilactones, three new dilactones, a derived lactone hydroxy ester and a known germacranolide.

Leaves of Montanoa karwinskii afforded in addition to known sterols, triterpenes and kaurane derivatives, four germacra-12,6β-olides. Three were new compounds, karwinsinolides A, B and C. Their structures were established by spectral methods, mainly NMR. A new seco-caryophyllene derivative was also isolated.