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Two new diterpenoid derivatives 7α,12β,17-triacetoxy-6β,19-dihydroxy-13β,16-spirocicloabiet-8-ene-11,14-dione (1) and 6β-acetoxy-3β,7α,12α-trihydroxy-13β,16-spirocicloabiet-8-ene-11,14-dione (2) along with 11 (3–13) miscellaneous compounds were isolated from the leaves of Plectranthus ornatus Codd. Their structures were elucidated by spectroscopic analysis and gauge independent atomic orbitals 13C NMR calculations. The isolated compounds were screened for their effects on intestinal motility using guinea-pig ileum and duodenum and by their cytotoxicity against 4 human cancer cell lines (HCT-116, SF-295, PC-3, and HL-60). Compounds 6 and 9 were moderately cytotoxic against HL-60, whereas 6 and 13 were more active on SF-295 and HCT-116.

The phytochemical reinvestigation from the heartwood of the extracts of Cordia glazioviana led to the isolation of four still undescribed hydroquinones derivatives designated as cordiaquinol D (1), cordiaquinol E (2), (10R)-10,11-dihydrofuran-1,4-dihydroxy-globiferin (3) and 2-[(1’E,6’E)-3’,8’‑dihydroxy-3’,7’-dimethylocta-1’,6’-dienyl]-benzene-1,4-diol (4), along with the naphthoquinone 6-[(2’R)-2’-hydroxy-3’,6’-dihydro-2H-pyran-5’-yl]-2‑methoxy- 7‑methylnaphthalene-1,4-dione (5). Additionally, six previously known compounds were also isolated: rel-1,4-dihydroxy-8α,11α;9α,11α-diepoxy-2-methoxy-8aβ-methyl- 5,6,7,8,8a,9,10,10a‑octahydro-10-antracenone (6), didehydroconicol (7), 1β,6β-dihydroxy-7-epieudesm-3-ene (8), 1β,6β-dihydroxy-7-epi-eudesm-4(15)-ene (9), 10,11-dihydroxybisabolol (10), and hamanasal-A (11). The structures of the new compounds were assigned by high-resolution mass spectrometry (HRMS) and nuclear magnetic resonance (NMR) analyses. The relative stereochemistry of 3, 4, and 5 was improved by quantum mechanical calculations. Eight, out of the eleven isolated compounds (2-9), were tested through cellular viability and lipopolysaccharide (LPS)-induced inflammation assays against RAW 264.7 macrophage-like cells. Compounds 3-5 exhibited a stronger effect on LPS-induced NO production (half-maximal inhibitory concentration (IC50) 50.34, 105.83, and 66.73 μM, respectively).

Withanolides constitute a valuable class of bioactive natural products because some members of the class are known to exhibit cytotoxic activity and also induce a cytoprotective heat-shock response. In order to understand the relationship between their structures and these dual bioactivities of the withanolide scaffold, we obtained 25 analogues of withaferin A (WA) and withanolide D (WD) including 17 new compounds by semisynthesis involving chemical and microbial transformations. Hitherto unknown 16β-hydroxy analogues of WA and WD were prepared by their reaction with triphenylphosphine/iodine, providing unexpected 5β-hydroxy-6α-iodo analogues (iodohydrins) followed by microbial biotransformation with Cunninghamella echinulata and base-catalyzed cyclization of the resulting 16β-hydroxy iodohydrins. Evaluation of these 25 withanolide analogues for their cytotoxicity and heat-shock-inducing activity (HSA) confirmed the known structure-activity relationships for WA-type withanolides and revealed that WD analogues were less active in both assays compared to their corresponding WA analogues. The 5β,6β-epoxide moiety of withanolides contributed to their cytotoxicity but not HSA. Introduction of a 16β-OAc group to 4,27-di- O-acetyl-WA enhanced cytotoxicity and decreased HSA, whereas introduction of the same group to 4- O-acetyl-WD decreased both activities.

The new glucosyl sarpagan alkaloid designated as 21(R*)-(O-β-glucosyl)-hydroxy-sarpagan-17-oic acid, along with eleven known alkaloids were isolated from a soluble alkaloidal fraction from the ethanol extract of Rauvolfia ligustrina. Their structures were elucidated by interpretation of spectroscopic data (1D and 2D NMR), HRESIMS experiment, GIAO 13C NMR calculations, and comparison with literature data. All the isolated alkaloids were screened by their neuroinhibitory effects using the electrically stimulated mice vas deferens bioassay. Compounds 1, 2 and 9 presented a potent inhibitory effect in the neurotransmission while 3 and 11 showed an acute neuroexcitatory effect. Compound 10 exhibited a very effective post-synaptic inhibitory activity.

Three new 3-hydroxy-N-methyl-2-oxindole (1 and 2) and 4-hydroxy-pyran-2-one (3) derivatives, along with the known 3-hydroxy-N-methyl-2-oxindole (4) and 6-methoxy-N-methylisatin (5) were isolated from a marine Salinispora arenicola strain from sediments of the St. Peter and St. Paul Archipelago, Brazil. The structures of the new compounds were elucidated by a combination of spectroscopic (1D and 2D NMR and HR-ESIMS) data, including single-crystal X-ray diffraction analysis for 2 and 3. Compounds 1 to 5 were assayed for their antimicrobial properties, but only 4 and 5 were active against Enterococcus faecalis with MIC value of 15.6 μg/mL.

Seven withanolides, including four previously unknown, were isolated from the acetone and ethanol extracts of cultivated specimens of Acnistus arborescens . These four compounds were identified as rel -(18 R ,22 R )-5 β ,6 β :18 β ,20-diepoxy-3 β ,18 α -dimethoxy-4 β -hydroxy-1-oxowith-24-enolide, rel -(20 R ,22 R )-5 β ,6 β -epoxy-4 β ,16 α ,20-trihydroxy-1-oxowitha-2,24dienolide, rel -(20 R ,22 R )-16 α -acetoxy-6 α -chloro-4 β ,5 β ,20-trihydroxy-1-oxowitha-2,24-dienolide and rel -(20 R ,22 R )-16 α -acetoxy-20-hydroxy-1-oxowitha-2,5,24-trienolide. Their structures were elucidated by interpretation of spectroscopic data (1D and 2D NMR), HRESIMS experiments and comparison with published data for similar compounds. Cytotoxicity of the isolated compounds was evaluated against a panel of four tumor cell lines (HL-60, HCT-116, SF-268 and PANC-1). Withanolide D was the most active, with an IC 50 value in the range of 0.3–1.7 μM, rel -(18 R ,22 R )-5 β ,6 β :18 β ,20-diepoxy-3 β ,18 α -dimethoxy-4 β -hydroxy-1-oxowith-24-enolide and rel -(20 R ,22 R )-5 β ,6 β -epoxy-4 β ,16 α ,20-trihydroxy-1-oxowitha-2,24dienolide were moderately active, while all the others were non-cytotoxic.

Amphidinolides are cytotoxic macrolides produced by symbiotic unicellular microalgae of the genus Amphidinium. Here we describe the identification of four related molecules belonging to this macrolide family isolated from the invertebrate Stragulum bicolor. The new molecules, named amphidinolide PX1-PX3 and stragulin A (1&ndash, 4), show an unprecedented carbon skeleton whose complete stereochemistry has been determined by spectroscopic and computational methods. Differences in the structures of these molecules modulate their biological activity in a panel of tumor cell lines, but the opened derivative stragulin (4) shows a very potent and specific cytotoxic activity (IC50 0.18 &micro, M) against the aggressive human melanoma cell A2058.

Three new plakortides, 7,8-dihydroplakortide E (1), 2, and 10, along with known natural products 3, 4, spongosoritin A (5), 6-8, and plakortide P (9), were isolated from Brazilian specimens of Plakortis angulospiculatus. Compounds 2, 3, 5, and 7-9 displayed cytotoxic activities with IC50 values ranging from 0.2 to 10 μM. Compounds that contained a dihydrofuran ring were generally less active and displayed time dependence in their activity. The activities of compounds 2 and 7-9, carboxylic acids bearing a common six-membered endoperoxide, were higher overall than for compounds 3 and 5. The modes underlying the cytotoxic actions of plakortides 2, 3, 5, 7, and 9 were further investigated using HCT-116 cells. While dihydrofurans 3 and 5 induce a G0/G1 arrest, six-membered peroxides 2, 7, and 9 delivered a G2/M arrest and an accumulation of mitotic figures, indicating a distinctly different antimitotic response. Confocal analysis indicated that microtubules were not altered after treatment with 2, 7, or 9, therein suggesting that the mitotic arrest may be unrelated to cytoskeletal targets. Overall, we find that two related classes of natural products obtained from the same extract offer cytostatic activity, yet they do so through discrete pathways.

Five new meroterpenoid compounds designed as rel -10 β ,11 β -epoxy-2,11-dimethoxy-8 α -hydroxy-8a β -methyl-5 α ,6,7,8,8a,9,10,10a β -octahydro-1,4-anthracendione ( 1 ), rel -10 β ,11 β -epoxy-8 α ,5-dihydroxy-2-methoxy-8a β -methyl-5,6,7,8,8a,9,10,10a β -octahydro − 1.4-anthracendione ( 2 ), rel -1,4,8 α -trihydroxy-5-furanyl-2-methoxy-8a β -methyl-6,7,8, 8a,9,10-hexahydro-10-anthracenone ( 3 ), rel -10 α ,11 α -epoxy-8 α ,11 β -dihydroxy-8a β -methyl-5 β ,6,7,8,8a,9,10,10a β -octahydro-1,4-anthracenediol ( 4 ) and rel -1,4,8α-trihydroxy-5-carboxyethyl-2-methoxy-8a β -methyl-6,7,8,8a,9,10-hexahydro-10-anthra-cenone ( 5 ), besides seven ( 6 – 12 ) known compounds were isolated from the heartwood and sapwood ethanol extracts of Cordia oncocalyx . Moreover, the main isolated compounds were screened using the electrically driven mice vas deferens bioassay, which has a rich pharmacological receptors diversity.

The chemical investigation of the brown alga Dictyota menstrualis provided three previously unreported prenylated guaiane diterpenes derivatives named as dictyols K, M and N (1 - 3), along with five structurally known diterpenoids (4 - 8). The structures of the new compounds, including their relative stereochemistry, were established by nuclear magnetic resonance (NMR) and high resolution mass spectrometry (HRMS) data analysis. In addition, their structures were improved by quantum mechanical calculations. Anti-inflammatory, antimicrobial and cytotoxic assays were performed with the isolated compounds, however, only the anti-inflammatory activity was particularly prominent. The cell viability effects of 1 - 8 on murine macrophage cell line (RAW 264.7) showed IC50 values ranging from 1.12 to 2.53 μM, and the inhibitory activity against the nitric oxide production over the lipopolysaccharide-stimulated RAW 264.7 cell was observed for all compounds with IC50 values ranging to 0.12 - 0.23 μM.

Five new diterpenes derivatives named as ornatin A, B, C, D and E, in addition to six known related diterpenes were isolated from the aerial parts of cultivated specimens of Plectranthus ornatus. The structures were elucidated using a combination of 1D/2D nuclear magnetic resonance (NMR) spectroscopy, high-resolution electrospray ionization mass spectrometry (HRESIMS) and comparison with published NMR data of analogous compounds. All isolated compounds were assayed against four human cancer cell lines, and Gram-positive and Gram-negative bacteria strains. None of them showed any cytotoxic activity, but ornatin C, D, E and three related diterpenes displayed marginal bactericidal or bacteriostatic effects against the Gram-positive strains.

The chemical study of the Brazilian brittle star Ophionereis reticulata led to the isolation of three chamigrene sesquiterpenes, including the partially characterized isoobtusadiene (1), its unreported acetyl derivative (2), and the known (+)-elatol (3). The complete elucidation of the structures 1 and 2 was accomplished by 1D and 2D NMR spectroscopy. The first assignment of the absolute configuration of the isoobtusadiene skeleton is suggested as 6S,9R,10S on the basis of the NMR analysis of the Mosher's ester derivatives of 1 and the ECD study of the acetyl derivative 2. Chamigrenes are typical constituents of Laurencia red algae. O. reticulata is a predator with a preference for algae. Thus, the origin of these metabolites can be likely ascribed to diet.

Two new epimeric chlorinated withaphysalins, rel-(4β,5β,6α,18S,22R)- and rel-(4β,5β,6α,18R,22R)-6-chloro-18,20-epoxy-18-ethoxy-4,5-dihydroxy-1-oxowitha-2,24-diene-26,22-lactone (1 and 2 resp.), together with the new rel-(4β,5β,6α,18R,22R)-6-chloro-18,20-epoxy-4,5-dihydroxy-18-methoxy-1-oxowitha-2,24-diene-26,22-lactone (3) and rel-(3β,4β,5β,6β,18R,22R)-5,6:18,20-diepoxy-3,18-diethoxy-4-hydroxy-1-oxowith-24-ene-26,22-lactone (4) were isolated from the leaves of Acnistus arborescens and named withaphysalins T–W, respectively. The final structures and the complete 1H- and 13C-NMR assignments of the three chlorowithaphysalins 1–3 were performed by means of HR-ESI-MS and 1D- and 2D-NMR experiments, including COSY, HSQC, and HMBC, beside comparison with spectral data of analogous compounds from the literature. The structure of 4 was also confirmed by means of a single-crystal X-ray diffraction analysis.

Two new furanoflavonoids, 5-hydroxy-2’’-isopropenyl-3-methoxyfurane-(2",3":7,8)-flavone and 5-hydroxy-2’’-(1-hydroxy-1-methylethyl)-3-methoxyfurane-(2",3":7,8)-flavone, along with thirteen other known compounds, were isolated from the root barks of Lonchocarpus obtusus (Leguminosae). The structures of all compounds were determined by spectrometric methods such as 1D and 2D NMR (COSY, HSQC and HMBC) and HREISMS beside comparison with spectral data for similar compounds. Dois novos furanoflavonoides, 5-hidróxi-2’’-isopropenil-3-metoxifurano-(2",3":7,8)-flavona e 5-hidróxi-2’’-(1-hidróxi-1-metiletil)-3-metoxifurano-(2",3":7,8)-flavona, juntamente com treze compostos conhecidos, foram isolados das cascas das raízes de Lonchocarpus obtusos (Leguminosae). As estruturas de todos os compostos isolados foram determinadas usando métodos espectrométricos tais como RMN 1D e 2D (COSY, HSQC e HMBC) e EMAR, além da comparação com dados espectrais descritos na literatura para compostos de estruturas semelhantes.

Four new anthracyclinones, 4,6,11-trihydroxy-9-propyltetracene-5,12-dione (1), 1-methoxy-9-propyltetracene-6,11-dione (2), 7,8,9,10-tetrahydro-9-hydroxy-1-methoxy-9-propyltetracene-6,11-dione (3), and 10β-carbomethoxy-7,8,9,10-tetrahydro-4,6,7α,9α,11-pentahydroxy-9-propyltetracene-5,12-dione (4), were isolated from a strain of Micromonospora sp. associated with the tunicate Eudistoma vannamei. All structures were established by 1D and 2D NMR (COSY, HSQC, HMBC, NOESY) and HRESIMS experiments. Compounds 1 and 4 were cytotoxic against the HCT-8 human colon adenocarcinoma cell line, with IC(50) values of 12.7 and 6.2 μM, respectively, while compounds 2 and 3 were inactive.

From the leaves of Solanum campaniforme, two new spirosolane alkaloids β-acetoxyl-(25S)-22βN-spirosol-4-en-3-one (1) and β-hydroxyl-(25S)-22βN-spirosol-4-en-3-one (4) were isolated along with two other known alkaloids of the same class (25S)-22βN-spirosol-1,4-dien-3-one (2) and (25S)-22βN-spirosol-4-en-3-one (3), which are reported for the first time as natural products. The structures of all alkaloids were established after an extensive analysis by 1D and 2D NMR spectroscopy (COSY, HSQC, HMBC and NOESY) as well as HRESIMS.

The chemical investigation of the ethanolic extract from leaves of Croton pedicellatus yielded the bis-nor-sesquiterpenes blumenol A and blumenol A glucoside, along with the flavonoids: tiliroside, 6"-O-p-coumaroyl-β-galactopyranosyl- kaempferol, 6"-O-p-coumaroyl-β-glucopyranosyl-3"-methoxy- kaempferol, kaempferol, 3-glucopyranosyl-quercetin and alpinumisoflavone, as well as 4-hydroxy-3,5-dimethoxybenzoic acid. The identification of all isolated compounds was performed by spectrometric methods, including HR-ESI-MS, 1D and 2D NMR experiments, and by comparison with previously-described physical and spectral data.

Five guanidine alkaloids, mirabilin B (1), 8bβ-hydroxyptilocaulin (2), ptilocaulin (3), and a mixture of the 8β- and 8α-epimers, 4 and 5, of 8-hydroxymirabilin (1,8a;8b,3a-didehydro-8-hydroxyptilocaulin), were isolated from Monanchora arbuscula colonies collected off the northeastern Brazilian coast. All structures were elucidated by spectroscopic analysis, including 1D (1H-, 13C- (BB), and 13C-DEPT) and 2D (COSY, HSQC, and HMBC) NMR experiments, and comparison with the literature data. The cytotoxicity of the isolated compounds were evaluated against four tumor cell lines, showing that mirabilin B (1) and the two epimers were inactive, while 8bβ-hydroxyptilocaulin (2) and ptilocaulin (3) presented IC50 values in the range of 7.9 to 61.5 μM, and 5.8 to 40.0 μM, respectively. Further studies on the mechanism of action of ptilocaulin, using HL-60 leukemia cells, demonstrated that this guanidine compound induced apoptosis of the treated cells.

Two new polymethoxylated flavonoids, 2′,5′,6′-trimethoxy-[2″,3″ : 3′,4′]furano dihydrochalcone and 2,4′,4,5-tetramethoxy-[2″,3″ : 6,7]-furanodihydroaurone, were isolated from the root barks of Lonchocarpus araripensis, along with the known compounds 3,4,5,6-tetramethoxy-[2″,3″ : 7,8]-furanoflavan, 3,6-dimethoxy-1″,1″-dimethylcromene-[2″,3″ : 7,8]-flavone, 3′,4′-methylenodioxy-5,6-dimethoxy-[2″,3″ : 7,8]-furanoflavone, 3,5,6-trimethoxy-[2″,3″ : 7,8]-furanoflavanone, 3,5,6-trimethoxy-[2″,3″ : 7,8]-furanoflavone, and 6α-hydroxy-medicarpin. The complete 1H and 13C NMR assignments of the new furan flavonoids were performed using 1D and 2D pulse sequences, including COSY, HSQC, and HMBC experiments, and comparison with spectral data for analog compounds from the literature, particularly for the new furanodihydroaurone because of several inconsistencies on the carbonyl chemical shifts from the literature. Copyright © 2008 John Wiley & Sons, Ltd.

From the roots of Cordia leucocephala (Boraginaceae), two new meroterpenoid naphthoquinones, 6-[10-(12,12-dimethyl-13alpha-hydroxy-16-methenyl-cyclohexyl)ethyl]-1,4-naphthalenedione (cordiaquinone L) and 5-methyl-6-[10-(12,12-dimethyl-13beta-hydroxy-16-methenyl-cyclohexyl)methyl-1,4-naphthalenedione (cordiaquinone M) were isolated. Their structures were elucidated after detailed 1D and 2D NMR (COSY, HSQC, HMBC and NOESY) data analyses and comparison with literature data for analogous compounds.

(1a S*,1b S*,7a S*,8a S*)-4,5-Dimethoxy-1a,7a-dimethyl-1,1a,1b,2,7, 7a,8,8a-octahydrocyclopropa cyclopenta[1,2-b]naphthalene-3,6-dione (1), a new meroterpenoid benzoquinone, and microphyllaquinone (2), a known naphthoquinone, have been isolated from roots of Cordia globosa. Both structure determinations were performed by conventional spectroscopic methods, including inverse detection NMR techniques, and by comparison with data from the literature for related compounds. Compound 1 displayed considerable cytotoxic activity against several cancer cell lines with IC50 values in the range of 1.2 to 5.0 microg/mL. The cytotoxic activity seemed to be related to DNA synthesis inhibition, as revealed by the reduction of 5-bromo-2'-deoxyuridine incorporation, and apoptosis induction, as indicated by the acridine orange/ethidium bromide assay and morphological changes after 24 h of incubation on leukemic cells.

A detailed NMR study and full assignments of the 1H and 13C spectral data for two novel triterpenoid saponins isolated from the stem bark of Pentaclethra macroloba (Willd.) Kuntze are described. Their structures were established using a combination of 1D and 2D NMR techniques including 1H,1H-COSY, TOCSY, NOESY, gs-HMQC and gs-HMBC, and also electrospray ionization mass spectrometry and chemical methods. The structures were established as 3beta-O-([O-beta-D-glucopyranosyl-(1--2)-O-beta-D-glucopyranosyl-(1--4)-O-beta-D-glucopyranosyl-(1--3)-O-alpha-L-rhamnopyranosyl-(1--2)]-[O-beta-D-glucopyranosyl-(1--3)-O-beta-D-glucopyranosyl-(1--4)])-alpha-L-arabinopyranosylhederagenin (1) and 3beta-O-)[O-beta-D-glucopyranosyl-(1--2)-O-beta-D-glucopyranosyl-(1--4)-O-beta-D-glucopyranosyl-(1--3)-O-alpha-L-rhamnopyranosyl-(1--2)]-[O-beta-D-glucopyranosyl-(1--3)-O-beta-D-glucopyranosyl-(1--4)])-alpha-L-arabinopyranosyloleanolic acid (2).

Two new secondary metabolites, the phenylpropanoid 3-(2',4',5'-trimethoxyphenyl)propanoic acid (1) and the sesquiterpene (+)-1beta,4beta,6alpha-trihydroxyeudesmane (2) were isolated from the heartwood of Cordia trichotoma Vell., along with the known sesquiterpenes (-)-1beta,4beta,7alpha-trihydroxyeudesmane (3) and (+)-1beta,4beta,11-trihydroxyoppositane (4). Their structures were elucidated by means of spectroscopic data interpretation, mainly 1D and 2D NMR and mass spectrometry.

Extensive 1D (1H NMR, HBBD-13C NMR, DEPT-13C NMR) and 2D (COSY, TOCSY, NOESY, HMQC and HMBC) NMR analysis was used to characterize the structure of a new bisdesmoside saponin isolated from the methanol extract of stems of Cordia piauhiensis Fresen as 3β-O-[α-L-rhamnopyranosyl-(1 2)-β-D-glucopyranosyl]ursolic acid 28-O-[β-D-glucopyranosyl-(1 6)-β-D-glucopyranosyl] ester. Copyright © 2003 John Wiley & Sons, Ltd.

One new alkaloid, 2α-10bα-dihydroxy-9-O-demethylhomolycorine, in addition to seven others known alkaloids, and 5-(hydroxymethyl)furfural, piscidic acid and eucomic acid, were isolated from the bulbs of Hippeastrum solandriflorum. The structures of all compounds were determined using nuclear magnetic resonance (NMR) spectroscopic techniques: 1H NMR and 13C NMR, heteronuclear single quantum coherence (HSQC), heteronuclear multiple bond correlation (HMBC), nuclear Overhauser effect spectroscopy (NOESY), and also the high-resolution electrospray ionization mass spectrometry (EI-HRMS). The cytotoxic activity of all alkaloids was evaluated against three human cancer cell lines (HCT-116, HL-60, OVCAR8 and SF-295) showing IC50 values ranging from 0.01 to 35.7 µM.

Two new meroterpenoid hydroquinones,rel-(4bE,6Z,8E,9aS,10S)-1,4-dihydroxy-9a,10-dihydro-10,12-epoxy-5-methylbenzo[a]azulen-12-one andrel-(4bZ,6Z,8E,9aS,10S)-1-hydroxy-9a,10-dihydro-4,11:10,12-diepoxy-benzo[a]azulen-11,12-dione, along with the known peptide derivative (S)-N-benzoylphenylalanine-(S)-2-benzamide-3-phenylpropyl ester, were isolated from the roots of Cordia globosa. Their structures were determined by 1D and 2D nuclear magnetic resonance (NMR) spectrometry, Fourier transform infrared (FTIR) spectroscopy and high resolution atmospheric pressure chemical ionization mass spectrometry (HRAPCIMS) data analysis. The new compounds were tested against three human cancer cell lines (colon adenocarcinoma, ovarian carcinoma and glioblastoma), but none of them exhibited any activity.

Conventional one-dimensional NMR methods and two-dimensional shift-correlated NMR experiments (COSY, HMQC, HMBC) were used for 1H and 13C chemical shift assignments of two naphthoquinone dimers tectol and tecomaquinone I isolated from Lippia sidoides. Copyright © 1999 John Wiley & Sons, Ltd.

A careful NMR analysis with full assignment of the 1H and 13C spectral data for two minor saponins isolated from stems of Cordia piauhiensis is reported. These saponins were isolated by high-performance liquid chromatography and characterized as 3beta-O-[alpha-L-rhamnopyranosyl-(1 --> 2)-beta-D-glucopyranosyl]pomolic acid 28-O-[beta-D-glucopyranosyl-(1 --> 6)-beta-D-glucopyranosyl] ester (1) and 3beta-O-[alpha-L-rhamnopyranosyl-(1 --> 2)-beta-D-glucopyranosyl]oleanolic acid 28-O-[beta-D-xylopyranosyl-(1 --> 2)-beta-D-glucopyranosyl-(1 --> 6)-beta-D-glucopyranosyl] ester (2). Their structures were established using a combination of 1D and 2D (1H, 1H-COSY, TOCSY, NOESY, gs-HMQC and gs-HMBC) NMR techniques, electrospray ionization mass spectrometry and chemical evidence.

Essential oils obtained by hydrodistillation from heartwood and sapwood of Cordia trichotoma Vell. were analyzed by GC/FID and GC/MS. The essential oil compositions were similar and characterized by their higher abundance on sesquiterpenes. The main components were: α-cadinol (26.5%), α-muurolol (25.1%), epi-α-muurolol (20.9%), δ-cadinene (11.9%) and guaia-3, 10(4)-dien-11-ol (10.7%). Copyright © 2004 John Wiley & Sons, Ltd.

From the leaves of Solanum campaniforme (Solanaceae), eight solanidane alkaloids were isolated, four of which contain a p-hydroxyphenylethylamine unit. Their structures were established as: 22b,23b-epoxysolanida- 1,4-dien-3-one; 22a,23a-epoxy-10-epi-solanida-1,4,9-trien-3-one; 22a,23a-epoxy-solanida-4- en-3-one; 22b,23b-epoxy-solanida-4-en-3-one; (E)-N-[80(4-hydroxyphenyl)ethyl]-22a,23a-epoxy-solanida-1, 4,9-trien-3-imine; (E)-N-[80(4-hydroxyphenyl)ethyl]-22a,23a-epoxy-solanida-1,4-dien-3-imine; (Z)-N- [80(4-hydroxyphenyl)ethyl]-22a,23a-epoxy-solanida-1,4,9-trien-3-imine and (Z)-N-[80(4-hydroxyphenyl) ethyl]-22a,23a-epoxy-solanida-1,4-dien-3-imine. All structures were determined using spectroscopic techniques, such as 1D and 2D NMR, and HRESIMS. The cytotoxicity and the antiophidic activities of the alkaloids were evaluated. The alkaloids did not show any cytotoxicity, but inhibited the main toxic actions of Bothrops pauloensis venom.

The chemical investigation of the stem EtOH extract of S. buddleifolium resulted in the isolation of terpenoids, amides, lignans and a steroidal alkaloid. Based on HRMS, IR and ¹H and 13C NMR data analysis, the structures of the isolated compounds were identified as: 13-hydroxysolavetivone, betulinic acid, N-trans-caffeoyltyramine, N-trans-feruloyldopamine, N-trans-p-cumaroyltyramine, N-trans-feruloyltyramine, N-trans-feruloyl3'-O-methoxydopamine, alangilignoside C, isolariciresinol, polistachiol, (+)-(8R,7'S,8'S)-3α-O-(β-D-glucopiranosyl)-lioniresinol, (-)-(8S,7'R,8'R)-3α-O-(β-D-glucopiranosyl)-lioniresinol and solamargine. The occurrence of terpenoids and amides is common in Solanum, unlike lignans which are rare. The isolated lignans described in this work are reported for the first time in the genus Solanum.

The zoanthids Palythoa caribaeorum and Protopalythoa variabilis are among the most abundant marine species along the Brazilian coast. We now report the isolation and structure elucidation of two unprecedented sulfonylated ceramides, palyosulfonoceramide A (1) and palyosulfonoceramide B (2) from specimens collected off Brazil’s northeastern coast. The structures of 1 and 2 were established using a combination of NMR analyses, including: evaluation of 1H, 13C, 1H–1H COSY, 1H–13C HSQC, 1H–13C HMBC, and 1H–15N HMBC NMR spectra, high-resolution mass spectrometry and chemical degradation. In addition, we also isolated the corresponding known ceramides, N-((2S,3R,4E,8E)-1, 3-dihydroxyoctadeca-4,8-dien-2-yl)-hexadecanamide (3) and N-((2S,3R,4E)-1,3-dihydroxy octadeca-4-en-2-yl)-hexadecanamide (4), which provided further support for the assignments of 1 and 2.

The chemical investigation of roots of Cordia polycephala resulted in the isolation of two new terpenoid naphtoquinones, 6-[10-(12,12-dimethyl-13α-(22-methyl-21-butenoyloxy)-16-methenylcyclohexyl)ethyl]-naphtalene-1,4-dione and (6-[10-(12,12-dimethyl-13α-(tigloyloxy)-16-methenylcyclohexyl)ethyl]-naphtalene-1,4-dione, named as cordiaquinone N (1) and O (2), respectively. The known cordiaquinones B (3), L (4) and E (5) were also isolated. Their structures were elucidated after detailed 1D and 2D NMR and high resolution electrospray ionization mass spectrometry (HRESIMS) data analysis. All cordiaquinones (1-5) were evaluated against four human cancer cell lines: HCT-8 (colon), HL-60 (leukemia), MDA-MB-435 (melanoma) and SF295 (glioblastoma), showing IC50 values in the range of 1.2 to 11.1 mmol L-1. The new cordiaquinones 1 and 2 were the most active against all cancer cell lines, while compound 3 was selective to leukemia HL-60 cells (IC50 2.2 mmol L-1). A investigação química das raízes de Cordia polycephala resultou no isolamento de duas novas naftoquinonas terpenoídicas, 6-[10-(12,12-dimetil-13α-(22-metil-21-butenoilóxi)-16-metenilciclohexil)etil]-naftaleno-1,4-diona e (6-[10-(12,12-dimetil-13α-(tigloilóxi)-16-metenilciclohexil)etil]-naftaleno-1,4-diona, designadas de cordiaquinonas N (1) e O (2), respectivamente. As cordiaquinonas já conhecidas, B (3), L (4) e E (5), foram também isoladas. Suas estruturas foram elucidadas após detalhada análise dos dados de RMN ¹H e 13C (1D e 2D) e EMAR (espectrometria de massas de alta resolução). Todas as cordiaquinonas (1-5) foram avaliadas contra quatro linhagens de células cancerígenas: HCT-8 (colo), HL-60 (leucemia), MDA-MB-435 (melanoma) e SF295 (glioblastoma), mostrando IC50 na faixa de 1,2 a 11,1 mmol L-1. As novas cordiaquinonas 1 e 2 foram as mais ativas contra todas as linhagens de câncer, enquanto 3 foi mais seletiva para células leucêmicas (IC50 2,2 µmol L-1).

The formation of paramagnetic species from oncocalyxone A in aprotic medium was confirmed by performing in situ electrochemical-electron spin resonance (E-ESR) experiments. The high delocalization of the radical generated at the first reduction potential is clearly evidenced by the hyperfine coupling of H-9 with the larger coupling constant, besides the couplings at the H-3 (close to quinone) and H-7 (far from the quinone nucleus) positions. In protic medium, together with pH dependence experiments, oncocalyxone A showed to be DNA-reactive through experiments with DNA sensors. Its reaction with N-acetylcysteine, with structural characterization of the addition products, proved its ability as Michael acceptor. Both aspects are important in terms of biological/pharmacological activities and indicate the present models as important tools in the screening of biologically active compounds. A formação de espécies paramagnéticas a partir da oncocalixona A em meio aprótico foi confirmada pela realização de experimentos eletroquímicos in situ em conjunto com ressonância de spin eletrônico (E-ESR). A alta deslocalização do radical gerado no primeiro potencial de redução está claramente evidenciada pelo acoplamento hiperfino do H-9 com a maior constante de acoplamento, além dos acoplamentos nas posições H-3 (próximo à quinona) e H-7 (distante do núcleo quinônico). Em meio prótico, além dos experimentos de dependência com o pH, oncocalixona A mostrou-se DNA-reativa por meio de experimentos eletroquímicos com sensores de DNA. Sua reação com N-acetilcisteína, com caracterização estrutural dos produtos de adição, evidencia sua habilidade como aceptor de Michael. Ambos os aspectos são importantes em termos de atividades biológicas/farmacológicas e indicam os presentes modelos como ferramentas importantes na avaliação de compostos biologicamente ativos.

Three new solanidane alkaloids bearing a 22,23-epoxy ring (1-3) and four known compounds were isolated from leaves of Solanum campaniforme. The structures were determined using spectroscopic techniques, including 1D and 2D NMR, and HRESIMS experiments. The antiophidic activity of the alkaloids was tested against Bothrops pauloensis venom. Compounds 1-3 completely inhibited myotoxicity without inhibiting phospholipase A2 activity of the venom, while hemorrhage and skin necrosis were significantly reduced in the presence of alkaloids 1 and 2.

A new flavone named 3,4',5,6-tetramethoxy-[2'',3'':7,8]furanoflavone besides the known flavonoids (2S,3R,4S)-3,4,5,8-tetramethoxy-[2'',3'':6,7]-furanoflavan, 3,6-dimethoxy-2'',2''-dimethylcromene-[2'',3'':7,8] -flavone, 3,5,6-trimethoxy-[2'',3'':7,8]-furanoflavone, 2,4',4,5-tetramethoxy-[2'',3'':6,7]-furanodihydroaurone, (2R,3S,4S)-3,4,5,6-tetramethoxy-[2'',3'':7,8]-furanoflavan and 3',4'-methylenodioxy-5,6-dimethoxy-[2'',3'':7,8]-furanoflavone were isolated from the root barks of Lonchocarpus campestris. The complete 1H and 13C NMR assignments of the new furan flavonoid was performed using 1D and 2D pulse sequences, including COSY, HMQC and HMBC experiments.

The new cordiachromes 1 and 2, named oncocalyxones A and B, have been Isolated from the wood of Auxemma oncocalyx. Their structures were deduced from spectroscopic data, Including 2D NMR experiments, and chemical transformations.

Two new labdane diterpenes, 6α-malonyloxy-ethyl ester manoyl oxide and bis-6α-dioxymanoylmalonate, together with the known 6α-hydroxymanoyl oxide, 6α-malonyloxymaloyl oxide and betulinic acid were isolated from leaves of Stemodia trifoliata. Their structures were elucidated by spectroscopic studies (IR and HR-ESI-MS), including an extensive NMR (COSY, HSQC, HMBC and NOESY) analysis. Copyright © 2010 John Wiley & Sons, Ltd.

The phytochemical investigation of extracts from the branch wood and branch barks of Andira surinamensis yielded a novel isoflavone dimer, 4′-methoxyisoflavone-(7-O-7″)-3″′,4″′-methylenedioxyisoflavone (surinamensin), along with the triterpene lupeol and the known isoflavones 5,7-dihydroxy-4′-methoxyisoflavone (biochanin A), 5,4′-dihydroxy-7-methoxyisoflavone (prunetin), 7,3′-dihydroxy-4′-methoxyisoflavone (calycosin), and 5,7,3′-trihydroxy-4′-methoxyisoflavone (pratensein). The structure of the new isoflavone was elucidated by 1D and 2D homonuclear and heteronuclear NMR spectroscopy and by comparison with published data for closely related compounds. Copyright © 2008 John Wiley & Sons, Ltd.

A detailed study on the cytotoxic effects of five known constituents isolated from the flowers and roots of Eupatorium betonicaeforme is reported, including 2,2-dimethyl-6-vinylchroman-4-one (1), 2-senecioyl-4-vinylphenol (2), 6-acetyl-2,2-dimethylchroman-4-one (3), (4E)-8beta-angeloyloxy-9beta,10beta-dihydroxy-1-oxogermacra-4,11(13)-dien-12,6alpha-olide (4), and 3beta-hydroxyicosan-1,5beta-olide (5). The sesquiterpene lactone 4 exhibited the highest cytotoxicity, with IC50 values ranging from 3.9 to 9.9 microM, showing some degree of cell selectivity. The antiproliferative activity of 4 was examined towards HL-60 cells, and found to diminish cell viability in a dose-dependent manner. Moreover, at all concentrations tested, there was a decrease in the number of cells capable of incorporating 5-bromo-2'-deoxyuridine (BrdU), indicating disruption of DNA synthesis. The morphological changes induced by 4 were compatible with apoptotic cell death. This work, thus, corroborates the anticancer potential of Eupatorium secondary metabolites.

Two new bidesmoside triterpenoid saponins were isolated from stems of Cordia piauhiensis. Their structures, characterized as 3-O-alpha-L-rhamnopyranosyl-(1 --> 2)-beta-D-glucopyranosyl pomolic acid 28-O-beta-D-glucopyranosyl ester (1) and 3-O-alpha-L-rhamnopyranosyl-(1 --> 2)-beta-D-glucopyranosyl oleanolic acid 28-O-beta-D-glucopyranosyl-(1 --> 6)-beta-D-glucopyranosyl ester (2), were unequivocally established after extensive NMR (1H, 13C, DEPT 135 degrees, COSY, HSQC, HMBC, TOCSY, and NOESY) studies.

The phytochemical investigation of carnauba wax led to the isolation of three new dammarane triterpenoids 1, 2 and 4, together with the known triterpene 3. The structures of the new compounds were determined by 1D and 2D NMR spectroscopy and by comparison with published data for closely related compounds.

We have evaluated the in-vitro and in-vivo antitumour activity of physalin B and physalin D isolated from the aerial parts of Physalis angulata. In-vitro, both compounds displayed considerable cytotoxicity against several cancer cell lines, showing IC50 values in the range of 0.58 to 15.18 μg mL−1 for physalin B, and 0.28 to 2.43 μg mL−1 for physalin D. The antitumour activity of both compounds was confirmed in-vivo using mice bearing sarcoma 180 tumour cells. The in-vivo antitumour activity was related to the inhibition of tumour proliferation, as observed by the reduction of Ki67 staining in tumours of treated animals. Histopathological examination of the kidney and liver showed that both organs were affected by physalin treatment, but in a reversible manner. These compounds were probably responsible for the previously described antitumour activity of ethanol extracts of P. angulata, and their identification and characterization presented here could explain the ethnopharmacological use of this species in the treatment of cancer.

Helindicine (1), a new pyrrolizidine alkaloid with unusual structural features, together with the known lycopsamine (2), were isolated from the roots of Heliotropium indicum (Boraginaceae). The structures were established by a combination of 1D and 2D NMR methods (COSY, HMQC, HMBC, and NOESY) and HREIMS. This is the first report of a lactone pyrrolizidine alkaloid in the genus Heliotropium. Compounds 1 and 2 were assayed for antioxidant activity and showed moderate activity. Um novo alcalóide denominado Helindicina (1), e o conhecido licopsamina (2) foram isolados das raízes de Heliotropium indicum (Boraginaceae). As estruturas foram estabelecidas tendo como base um amplo estudo de 1D e 2D RMN (COSY, HMBC, HMQC, NOESY) e HREIMS. Este representa o primeiro relato de um alcalóide contendo um anel lacônico no gênero Heliotropium. Estes alcalóides mostraram moderada atividade antioxidante.

Two new compounds, 5 and 8, and an epimeric mixture 4a/4b were isolated from hardwood of Auxemma glazioviana. Their structures and relative configurations were determined by modern spectroscopic analysis to be rel-10alpha,11alpha-epoxy-11beta-ethoxy-8alpha- hydroxy-2-methoxy -8abeta-methyl-5,6,7,8,8a,9,10,10abeta-octahydro-1,4-anthracenedione (or rel-2R,2aR,5R,5aS ,10bS,10cS-2-ethoxy-5-hydroxy-8-methoxy-5a-methyl- 2a,3,4,5,5a,6,10b,10c-octahydro-2H-anthra[9,1-bc]furan-7,10-dione, 4a), rel-10alpha,11alpha- epoxy-11alpha-ethoxy-8alpha-hydroxy-2-methoxy-8abeta-methyl-5,6,7,8,8a,9,10,10abeta-octahydro- 1,4-anthracenedione (or rel-2S,2aR,5R,5aS ,10bS,10cS-2-ethoxy-5-hydroxy-8-methoxy- 5a-methyl-2a,3,4,5,5a,6,10b10c-octahydro-2H-anthra[9,1-bc]furan-7,10-dione, 4b), rel-10alpha,11alpha-epoxy-8alpha,11-dihydroxy-2-methoxy-8abeta-methyl-5,6,7,8,8a,9,10,10abeta- octahydro-1,4-anthracenedione (or rel-2S,2aR,5R,5aS ,10bS,10cS-2,5-dihydroxy-8- methoxy-5a-methyl-2a,3,4,5,5a,6,10b,10c-octahydro-2H-anthra[9,1-bc]furan-7,10 -dione, 5) and rel-10,11-epoxy-8abeta-methyl-1,4,5alpha,9alpha-tetrahydroxy-5,6,7,8,8a,9,10,10a- octahydro-8-anthracenone (or rel-2aS,5aS,6R,10bR ,10c5-2a,6,7,10-tetrahydroxy-5a-methyl-2a,3,4,5,5a,6,10b,10c-octahydro-2H-anthra [9,1-bc]-furan-5-one, 8). In addition, known compounds were also isolated.

Phytochemical analysis of the leaves of Acnistus arborescens (Solanaceae) resulted in the isolation of two new epimeric withaphysalins (17S,20R,22R)-5beta,6beta: 18,20-diepoxy-4beta,18-dihydroxy-1-oxowitha-24-enolide (2, 18R and 18S), together with the known withaphysalin F (1, 18R and 18S). Their structures were established by spectroscopic methods, including 2D NMR data and comparison with literature data. Compounds 1 and 2 dis-played potent cytotoxic activities against several cancer cell lines with IC50 values in the range of 0.20 to 1.46 microg/mL for 1 and 0.89 to 8.08 microg/mL for 2. The strong cytotoxicity presented by 1 suggests that in this series of compounds, the 2,3-unsaturated ketone moiety is an important pharmacophoric unit. The cytotoxic activity seemed to be related to DNA synthesis inhibition, as revealed by the reduction of 5-bromo-2'-deoxyuridine incorporation after 24 hours of incubation on leukemic cells.

In the present work we studied the antinociceptive and antiedematogenic effects of a quinone fraction (QF) isolated from the heartwood of Auxemma oncocalyx Taub. The major constituent of QF, which represented around 80% of this fraction, was a terpenoid quinone named oncocalyxone A (1). Results show that QF (10 and 30 mg/kg body wt., i.p.) significantly inhibited paw edema induced by carrageenan at the second, third, and fourth hours. The effect was dose-dependent and long lasting, and QF was less effective orally. An antiedematogenic effect was also demonstrated in the dextran-induced paw edema. In this model, however, QF was somewhat less potent. QF (1 and 5 mg/kg body wt., i.p.) inhibited acetic acid-induced abdominal contractions in mice in a dose-dependent manner. In addition, QF (5 and 10 mg/kg body wt., i.p.) inhibited only the second phase (inflammatory) in the formalin test, and showed no effect in the hot-plate test in mice. The antinociceptive activity of QF was predominantly peripheral and independent of the opioid system. The observed effects of QF are, at least in part, probably due to the presence of oncocalyxone A (1).

A new prenylated naphthoquinone dimer named microphyllaquinone (1), a mixture of 6-methoxy- and 7-methoxy-naphtho[2,3-b]-furan-4,9-quinones (2a/2b) and tecomaquinone I (3), were isolated from roots of Lippia microphylla. The structures were elucidated by spectroscopic methods, including detailed 1D and 2D (COSY, NOESY, HMQC, HMBC) NMR data. Unpublished 13C NMR data of 2a and 2b are reported. The in vitro cytotoxic activity of the isolated compounds was tested against five types of tumor cells.