A new C9nor-isoprenoid glucoside fromRantherium suaveolens

The new C(9) nor-isoprenoid 3-methyl-octa-1,5-diene-7-one-3-O-beta-D-glucopyranoside, named as ranthenone glucoside (1), together with the previously known 9-hydoxylinaloyl glucoside (2), sitosterol-3beta-O-[6'-palmitoyl-beta-D-glucopyranoside] (3), scopoletin (4), fraxetin (5), and scopolin (6), were isolated from the aerial parts of Rantherium suaveolens. The structures of these compounds were elucidated by extensive spectroscopic analysis.

Antioxidant compounds from Ebenus pinnata

Activity-guided fractionation of the methanol extract of Ebenus pinnata aerial parts led to the isolation of ombuoside (1), kaempferol 3-O-rutinoside (2), rutin (3), catechin (4), and picein (5), along with beta-sitosterol and beta-sitosterol glucoside. Compounds 1-4 showed significant antioxidant activity in the DPPH, and TEAC, reducing power assays.

Phytochemical constituents from Salsola tetrandra

The new norisoprenoid 3beta-hydroxy-5alpha,6alpha-epoxy-beta-ionone-2alpha-O-beta-d-glucopyranoside (1) and the long-chain hydroxy fatty acids 9,12,13-trihydroxyoctadeca-10(E),15(Z)-dienoic acid (2) and 9,12,13-trihydroxyoctadeca-10(E)-dienoic acid (3) were isolated from Salsola tetrandra aerial parts, together with 3,4,5-trimethoxyphenyl-beta-d-glucopyranoside (4), 9-hydroxylinaloyl glucoside (5), taxiphyllin (6), trans-N-feruloyltyramine (7), and S-(-)-trans-N-feruloyloctopamine (8). Their structures were elucidated by extensive spectroscopic analysis and chemical methods. Compounds 6 and 8 displayed mild antibacterial activity against Staphylococcus aureus, whereas compound 6 showed the highest activity in the Artemia salina bioassay.

Euphoportlandols A and B, tetracylic diterpene polyesters from Euphorbia portlandica and their anti-MDR effects in cancer cells

Two new tetracyclic diterpene polyesters, euphoportlandols A (1) and B (2), have been isolated along with 12 known tetracyclic triterpenes from an acetone extract of Euphorbia portlandica. Their structures were established as 5alpha,11alpha,14alpha,17-tetraacetoxy-3beta-benzoyloxy-6beta,15beta-dihydroxy-9-oxoseget-8(12)-ene (1) and 5alpha,11alpha,14alpha,17-tetraacetoxy-3beta-benzoyloxy-6beta,15beta-dihydroxy-9-oxosegetane (2), respectively, by spectroscopic data interpretation. Compounds 1 and 2 were evaluated for their ability to inhibit multidrug resistance in cancer cells. Both compounds were found to be inhibitors of P-glycoprotein activity.

QSAR analysis of phenolic antioxidants using MOLMAP descriptors of local properties

Molecular maps of atom-level properties (MOLMAPs) were developed to represent the diversity of chemical bonds existing in a molecule. Chemical reactivity, being related to the ability for bond breaking and bond making, is primarily determined by the properties of bonds available in a molecule. In order to use physicochemical properties of individual bonds for an entire molecule, and at the same time having a fixed-length molecular representation, all the bonds of a molecule are mapped into a fixed-size 2D self-organizing map (MOLMAP). This article illustrates the application of MOLMAP descriptors to QSAR, with a study of the radical scavenging activity of 47 naturally occurring phenolic antioxidants. Counterpropagation neural networks (CPG NNs) were trained with MOLMAP descriptors selected using genetic algorithms to predict antioxidant activity. The model was subsequently validated by the leave-one-out (LOO) procedure obtaining a q(2) of 0.71. Random Forests were grown with the entire set of MOLMAP descriptors giving 70% of correct classifications as potent, active or inactive in a LOO experiment. Interpretations of both models in terms of discriminant variables were concordant and allowed identifying bonds and substructures that are mostly responsible for antioxidant activity. This work shows how MOLMAPs can be used for data mining of structural and biological activity data, leading to the extraction of relationships between local properties and activity.

New macrocyclic lathyrane diterpenes, from Euphorbia lagascae, as inhibitors of multidrug resistance of tumour cells

The new macrocyclic lathyrane diterpenes latilagascenes A and B ( 1 and 2), the diacetylated derivative of 2, latilagascene C ( 3), and the known diterpenes ent-16alpha,17-dihydroxyatisan-3-one ( 4) and ent-16alpha,17-dihydroxykauran-3-one ( 5), isolated from the methanol extract of Euphorbia lagascae, were examined for their effects on the reversal of multidrug resistance (MDR) on mouse lymphoma cells. Among the active lathyrane derivatives 1 - 3, compound 2 displayed the highest inhibition of rhodamine 123 efflux of human MDR1 gene transfected mouse lymphoma cells when compared to the untreated cells or the positive control verapamil. The new compounds are the first macrocyclic lathyrane diterpenes showing oxidation at C-16, whose structures were characterized by extensive spectroscopic methods, including 2D NMR experiments ( (1)H- (1)H COSY, HMQC, HMBC and NOESY). The known phenolic compounds vanillic acid ( 6), p-salicylic acid ( 7), isofraxidin ( 8) and cleomiscosin A ( 9) were also isolated from this species.

New ceramides from Rantherium suaveolens

A mixture of five new ceramides was isolated from the aerial parts of Rantherium suaveolens and characterized by spectroscopic and chemical methods. Their structures were elucidated by spectroscopic and chemical methods as (2S,3S, 4R,2'R, 14E)-2-(2'-hydroxydocosanoylamino) - 14 - octadecene -1,3,4-triol (1), (2S,3S,4R,2'R, 14E)-2-(2'-hydroxytricosanoylamino)-14-octadecene-1,3,4-triol (2), (2S,3S,4R,2'R, 14E)-2-(2'-hydroxytetracosanoylamino)- 14 - octadecene - 1,3,4 - triol (3), (2S, 3S,4R,2'R, 14E) - 2 - (2'- hydroxypentacosanoylamino) - 14 - octadecene - 1,3,4-triol (4), and (2S,3S,4R,2'R,14E)-2-(2'-hydroxyhexacosanoylamino)-14-octadecene-1,3,4-triol (5).

Antioxidant phenolic glycosides from Moricandia arvensis

The new phenolic glycosides quercetin 3,4'-di-O-beta-d-glucopyranoside-7-O-alpha-l-rhamnopyranoside (moricandin) (1), beta-d-glucopyranosyl 4-O-beta-d-glucopyranosylcaffeate (2), methyl 3-O-beta-d-glucopyranosyl-5-hydroxycinnamate (3), and beta-d-glucopyranosyl 4-O-beta-d-glucopyranosylbenzoate (4), together with the previously known beta-d-glucopyranosyl 4-hydroxybenzoate (5), methyl 4-O-beta-d-glucopyranosylcaffeate (6), 1-O-caffeoyl-beta-d-glucopyranoside (7), and 2-phenylethyl-beta-d-glucopyranoside (8), were isolated from the flowers of Moricandia arvensis. Their structures were elucidated by extensive spectroscopic analysis and chemical methods. Compounds 1-8 were evaluated for antioxidant activity using DPPH, TEAC, and reducing power assays, where the caffeic acid derivative 7 and the quercetin triglycoside 2 proved to possess the most potent scavenging activity.

A new sesquiterpene-coumarin ether and a new abietane diterpene and their effects as inhibitors of P-glycoprotein

A new sesquiterpene-coumarin ether (5'beta,9'alpha,10'alpha)-7-0-(3alpha-methoxy-8'(12')-drimen-11'-yl)-scopoletin, designated driportlandin (1) and a new abietane quinoid diterpene 16-hydroxy-abieta-8,12-diene-11,14-dione, named portlanquinol (2) together with lupeol, nepehinol, wrightial, formonetin and davidigenin were isolated and characterized from the Me2CO extract of whole dried plant of Euphorbia portlandica. The structures of the new compounds were elucidated from spectral data including 2D-NMR experiments of COSY, HMQC, HMBC and NOESY. When examined for their effects on the reversal of multidrug resistance(MDR) on mouse lymphoma cells, compound 1 proved to be more active than the positive control verapamil and compound 2 was found to be toxic. This is the first report on the isolation of a sesquiterpene-coumarin and a quinoid-type diterpenoid from Euphorbia.

Bioactive diterpenoids, a new jatrophane and two ent-abietanes, and other constituents from Euphorbia pubescens

A new jatrophane diterpene, pubescenol (1), known ent-abietane lactones, helioscopinolide A (2) and B (3), and taraxerone, 24-methylenecycloartanol, and vanillin have been isolated from Euphorbia pubescens. Diterpenes 1-3 and previously described pubescene D (4) were shown to be moderate inhibitors of the growth of MCF-7, NCI-H460, and SF-268 human tumor cell lines, whereas compounds 2 and 3 also exhibited significant antibacterial activity against Staphylococcus aureus.

Euphopubescenol and euphopubescene, two new jatrophane polyesters, and lathyrane-type diterpenes from Euphorbia pubescens

The structures of euphopubescenol and euphopubescene, two new macrocyclic jatrophane diterpene polyesters, isolated from the whole dried plant of Euphorbia pubescens, were established as 5alpha,8alpha,15beta-triacetoxy-3alpha-benzoyloxy -4alpha-hydroxy -9,14-dioxo-13beta H-jatropha-6(17),11 E-diene ( 1) and 3beta,7beta,8beta,9alpha,14alpha,15beta-hexaacetoxy-2beta H-jatropha-5 E,11 E-diene ( 2) by 1D- and 2D-NMR (COSY, HMQC, HMBC and NOESY), IR, EI-MS and EI-FTICR-MS. Two known lathyrane derivatives, jolkinol A ( 3) and jolkinol A ( 4), whose (13)C-NMR spectra were assigned, were also isolated. Compounds 1 - 3 have been evaluated for their ability to inhibit the in vitro growth of three human tumour cell lines representing different tumour types, MCF-7 (breast adenocarcinoma), NCI-H460 (non-small cell lung cancer) and SF-268 (CNS cancer). They inhibited both MCF-7 and NCI-H460 cell lines, with GI50 values ranging between 40.9 microM and 95.3 microM, but were found to be ineffective as growth inhibitors of the SF-268 cell line.

Effect of cycloartanes on reversal of multidrug resistance and apoptosis induction on mouse lymphoma cells

The ability of fifteen cycloartanes, isolated from Euphorbia species, to reverse multidrug resistance (MDR) and apoptosis induction in L5178Y mouse lymphoma cells, including its multidrug-resistant subline, was studied by flow cytometry. Reversion of MDR was investigated using a standard functional assay with rhodamine 123 as a fluorescent substrate analogue. For the evaluation of apoptosis, the cells were stained with FITC-labeled annexin V and propidium iodide. The majority of the compounds were able to reverse MDR of the tested human MDR1 gene-transfected mouse lymphoma cells. Some of the compounds were able to induce moderate apoptosis in the PAR cell line, but this effect was less effective on multidrug-resistant cells. The results indicate that cycloartanes can be substrates of ABC transporters, which might compete with certain anticancer chemotherapeutics.

Pubescenes, jatrophane diterpenes, from Euphorbia pubescens, with multidrug resistance reversing activity on mouse lymphoma cells

The macrocyclic jatrophane diterpene polyesters, pubescenes A - D ( 1 - 4) were isolated from the whole dried plant of Euphorbia pubescens, and evaluated for multidrug resistance (MDR) reversing activity on mouse lymphoma cells. All the compounds displayed very strong activity compared with the positive control verapamil. Pubescene D ( 4) is a new compound, whose structure was established as 3beta,9alpha,-diacetoxy-7beta-benzoyloxy-15beta-hydroxy-14-oxo-2beta H-jatropha-5 E,12 E-diene by spectroscopic methods, including (1)H- (1)H COSY, HMQC, HMBC and NOESY.

Rearranged jatrophane-type diterpenes from euphorbia species. Evaluation of their effects on the reversal of multidrug resistance

The rearranged jatrophane-type diterpenes ( 1 - 3), isolated from the Me (2)CO extracts of Euphorbia portlandica and Euphorbia segetalis, were examined for their effects on multidrug resistance (MDR) in mouse lymphoma cells. Compounds 2 and 3 revealed to be active with the latter being more active than the positive control verapamil, a known resistance modifier. The new compound 1, named portlandicine, was isolated from Euphorbia portlandica and its structure characterised by high-field NMR spectroscopic methods including 2D NMR techniques: COSY, HMQC, HMBC and NOESY. The known diterpene 2, together with aleuritolic acid ( 4), oleanolic acid ( 5), and betulin diacetate ( 6), were also isolated from the same species.

Three new jatrophane-type diterpenes from Euphorbia pubescens

Three new macrocyclic jatrophane diterpene polyesters, named pubescenes A ( 1), B ( 2), and C ( 3), and the known compounds indole-3-aldehyde and scopoletin have been isolated and characterised from the whole dried plant of Euphorbia pubescens. The structures of the new compounds were established by spectroscopic means including 2D-NMR techniques such as COSY, HMQC, HMBC and NOESY experiments. Compounds 1 - 3 were evaluated for their in vitro effect on the growth of three human cancer cell lines MCF-7 (breast), NCI-H460 (lung) and SF-268 (CNS) as well as for their capacity to interfere with the proliferation of human peripheral blood lymphocytes. They exhibited a moderate growth inhibitory effect on the cancer cell line NCI-H460. No effect was observed on the mitogenic response of human lymphocytes to PHA.

New trichothecenes isolated from Holarrhena floribunda

Bioassay-guided fractionation of an extract of Holarrhena floribunda stem, has led to the isolation of the new trichothecenes, 8-dihydrotrichothecinol A (1), loukacinol A (2), and loukacinol B (3), and the known compounds, trichothecolone (4), trichothecin (5), trichothecinol A (6), rosenonolactone (7), 6beta-hydroxyrosenonolactone (8), and rosololactone (9). The structures were determined by spectral and chemical methods, and absolute configurations were established by a modified Horeau's method using HPLC. Compounds 1 and 6 exhibited significant cytotoxicity against several human tumor cell lines, whereas compound 8 showed moderate and weak antileishmanial activity toward extracellular and intracellular Leishmania donovani, respectively.

Antimicrobial, antitumor and antileishmania screening of medicinal plants from Guinea-Bissau

Following an ethnobotanical search carried out in Guinea-Bissau, eighteen extracts derived from sixteen medicinal species were screened for antimicrobial, antitumor and antileishmania activity. Significant antitumor activity was found for Holarrhena floribunda against KB (squamous carcinoma), SK-Mel 28 (melanoma), A 549 (lung carcinoma) and MDA-MB 231 (mamma carcinoma) cell lines, with corresponding IC50 values of 7.9, 9.0, 3.4 and 9.9 micrograms/ml. Khaya senegalensis and Anthostema senegalense exhibited a significant activity against Leishmania donovani with IC50 values of 9.8 and 9.1 micrograms/ml, respectively. Most of the extracts showed week or moderate antibacterial and antifungal activity, with MIC values in the range 0.25-1.0 mg/ml. Active extracts were submitted to bioassay-guided fractionation, and the IC50 and MIC of the active fractions were determined.