Guillermo Schmeda-Hirschmann

Universidad de Talca, Talca, Maule, Chile

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Publications (151)287.23 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: Toads known as "cururú" (Rhinella schneideri) have been used in the Brazilian Pantanal and Paraguayan Chaco wetlands to treat erysipelas and cancer.
    Journal of ethnopharmacology. 06/2014;
  • Journal of Ethnopharmacology. 01/2014;
  • Cristina Quispe, Kerstin Petroll, Cristina Theoduloz, Guillermo Schmeda-Hirschmann
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    ABSTRACT: The traditional syrup made of Prosopis pods, known as “algarrobina” or “arrope de algarrobo” in the Andean countries, is commonly used in confectionery and local cuisine to prepare sweets and cocktails. The polyphenolic content of four Prosopis pods syrup samples as well as from the phenolic-enriched Amberlite-retained fraction of the syrup, were analyzed using reversed phase high performance liquid chromatography-diode array detector coupled to electrospray ionization mass spectrometry (HPL-DAD-ESI-MS). The main phenolics in the syrups were apigenin-derived C-glycosyl flavonoids, including 6,8-C-pentoside-C-hexoside, 6,8-dihexoside and quercetin glycosides. The sugar derivative 5-hydroxymethyl furfural was present in most of the samples. All syrups were devoid of cytotoxicity towards human lung fibroblasts and human gastric AGS cells, with IC50 values > 1000 μg/mL. The phenolic constituents of the syrups are C-glycosylflavonoids with known anti-inflammatory, antioxidant and other nutraceutical properties. The phenolic composition of South American algarrobo syrup is presented for the first time.
    Food Research International. 01/2014; 56:174–181.
  • Verónica Rachel Olate, Alex Soto, Guillermo Schmeda-Hirschmann
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    ABSTRACT: Little is known about the changes in resin composition in South American gymnosperms associated with the different seasons of the year. The diterpene composition of 44 resin samples from seven Austrocedrus chilensis (Cupressaceae) trees, including male and female individuals, was investigated in three different seasons of the year (February, June and November). Twelve main diterpenes were isolated by chromatographic means and identified by gas chromatography-mass spectrometry and nuclear magnetic resonance (NMR). The diterpene composition was submitted to multivariate analysis to find possible associations between chemical composition and season of the year. The principal component analysis showed a clear relation between diterpene composition and season. The most characteristic compounds in resins collected in summer were Z-communic acid (9) and 12-oxo-labda-8(17),13E-dien-19 oic acid methyl ester (10) for male trees and 8(17),12,14-labdatriene (7) for female trees. For the winter samples, a clear correlation of female trees with torulosic acid (6) was observed. In spring, E-communic acid (8) and Z-communic acid (9) were correlated with female trees and 18-hydroxy isopimar-15-ene (1) with male tree resin. A comparison between percent diterpene composition and collection time showed p < 0.05 for isopimara-8(9),15-diene (2), sandaracopimaric acid (4), compound (7) and ferruginol (11).
    Molecules (Basel, Switzerland). 01/2014; 19(5):6489-503.
  • Mariano Walter Pertino, Valery Verdugo, Cristina Theoduloz, Guillermo Schmeda-Hirschmann
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    ABSTRACT: Dehydroabietic acid (DHA) is a naturally occurring diterpene with different and relevant biological activities. Previous studies have shown that some DHA derivatives display antiproliferative activity. However, the reported compounds did not include triazole derivatives. Starting from DHA (8,11,13-abietatrien-18-oic acid), and its alcohol dehydroabietinol (8,11,13-abietatrien-18-ol), four alkyl esters were prepared. The alkyl terpenes were treated with different aromatic azides to synthesize hybrid compounds using click chemistry. Some 16 new DHA hybrids were thus synthesized and their structures were confirmed by spectroscopic and spectrometric means. The antiproliferative activity of the new compounds was assessed towards human cell lines, namely normal lung fibroblasts (MRC-5), gastric epithelial adenocarcinoma (AGS), lung cancer (SK-MES-1) and bladder carcinoma (J82) cells. Better antiproliferative effect was found for compound 5, with an IC50 of 6.1 μM and selectivity on SK-MES-1 cells. Under the same experimental conditions, the IC50 of etoposide, was 1.83 µM.
    Molecules 01/2014; 19(2):2523-35. · 2.43 Impact Factor
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    ABSTRACT: Copao (Eulychnia acida Phil., Cactaceae) is an endemic species occurring in arid areas of northern Chile. The fruits are commercialized by peasants within the Elqui and Limari valleys and are appreciated for its acidic and refreshing taste. We now report the total phenolic (TP) and total flavonoid (TF) content, antioxidant activity, phenolic composition and main phenolic distribution in pulp and epicarp of copao fruits from different harvesting places from both valleys. The ascorbic acid content was determined in fresh fruit pulp, epicarp and juice. The phenolic-enriched extract was analyzed for antioxidant effect and composition. Ferulic acid, 9,10-dihydroxy-4,7-megastigmadien-3-one hexoside, isorhamnetin and quercetin glycosides were identified by HPLC-DAD-MS/MS analysis. The main compounds were isolated and fully characterized by NMR techniques. The main phenolic in the samples was isorhamnetin-3-O-[α-rhamnopyranosyl-(1 → 6)-β-glucopyranoside]. The HPLC pattern of the phenolic-enriched extracts of the fruits allows a differentiation of samples from the Elqui and Limari valleys. All fruit extracts and Amberlite-retained fraction from the methanolic extract were devoid of toxicity against human gastric AGS cells and human lung fibroblasts, with IC50 values > 400 μg/mL for AGS and 344 to > 400 μg/mL for fibroblasts, respectively. The compounds identification, associated with the antioxidant activity and insignificant cell toxicity, add relevant information for the possible development of this native fruit into a new crop.
    Food Research International. 01/2014;
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    ABSTRACT: High speed centrifugal countercurrent chromatography (HSCCC) was successfully applied to preparative isolation of the main polar phenolics from the Peruvian Caricaceae Vasconcellea quercifolia A. St.-Hil. High-performance liquid chromatography with diode array (HPLC-DAD) and electrospray ionisation mass spectrometric detection (ESI-MS) was used to carry out a comprehensive characterisation of phenolic compounds from fruits and leaves of this plant. The main phenolics were the quercetin diglycoside rutin and the triglycoside manghaslin. Nine minor flavonoids were tentatively identified as kaempferol, quercetin, isorhamnetin and methoxymyricetin glycosides. HSCCC combined with other chromatographic methods allowed the isolation of the main phenolics from the plant. HPLC-DAD-MS analysis shows that the main phenolic compounds in V. quercifolia are similar to those described for V. pubescens but differs in the identity of the minor constituents.
    Journal of the Chilean Chemical Society 09/2013; 58(3):1830-1835. · 0.38 Impact Factor
  • Mario J Simirgiotis, Jorge Bórquez, Guillermo Schmeda-Hirschmann
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    ABSTRACT: Native Myrtaceae fruits were gathered by South American Amerindians as a food source. At present, there is still some regional consume of the small berries from trees belonging to genus Luma that occurs in southern Chile and Argentina. The aerial parts and berries from Luma apiculata and Luma chequen were investigated for phenolic constituents and antioxidant capacity. A high performance electrospray ionisation mass spectrometry method was developed for the rapid identification of phenolics in polar extracts from both species. Thirty-one phenolic compounds were detected and 27 were identified or tentatively characterised based on photodiode array UV-vis spectra (DAD), ESI-MS-MS spectrometric data and spiking experiments with authentic standards. Twelve phenolic compounds were detected in L. apiculata fruits and 12 in the aerial parts while L. chequen yielded 10 compounds in fruits and 16 in aerial parts, respectively. From the compounds occurring in both Luma species, seven were identified as tannins or their monomers, 15 were flavonol derivatives and five were anthocyanins. The whole berry and aerial parts extracts presented high antioxidant capacity in the DPPH assay (IC50 of 10.41±0.02 and 2.44±0.03μg/mL for L. apiculata, 12.89±0.05 and 3.22±0.05 for L. chequen, respectively), which can be related to the diverse range of phenolics detected. The antioxidant capacity together with the high polyphenolic contents and compounds identified can support at least in part, their use as botanical drugs. From the compounds identified in both species, 3-O-(6″-O-galloyl)-hexose derivatives of myricetin, quercetin, laricitrin and isorhamnetin are reported for the first time for the genus Luma.
    Food Chemistry 08/2013; 139(1-4):289-99. · 3.33 Impact Factor
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    ABSTRACT: The West African tree Keetia leucantha (Rubiaceae) is used in traditional medicine in Benin to treat malaria. The twigs dichloromethane extract was previously shown to inhibit in vitro Plasmodium falciparum growth with no cytotoxicity (> 100µg/ml on human normal fibroblasts). The dichloromethane and aqueous extracts of twigs of K. leucantha were evaluated in vivo against Plasmodium berghei NK 173 by the 4-day suppressive test and in vitro against a chloroquine-sensitive strain of Plasmodium falciparum (3D7) using the measurement of the plasmodial lactate dehydrogenase activity. Bioguided fractionations were realized and compounds were structurally elucidated using extensive spectroscopic analysis. The in vivo antimalarial activity of K. leucantha dichloromethane and aqueous twigs extracts were assessed in mice at the dose of 200mg/kg/day. Both extracts exhibited significant effect in inhibiting parasite growth by 56.8% and 53.0%, respectively (p<0.0001) on day 7-postinfection. An LC-MS analysis and bioguided fractionations on the twigs dichloromethane extract led to the isolation and structural determination of scopoletin (1), stigmasterol (2), three phenolic compounds: vanillin (3), hydroxybenzaldehyde (4) and ferulaldehyde (5), eight triterpenic esters (6-13), oleanolic acid and ursolic acid. The antiplasmodial activity of the mixture of the eight triterpenic esters showed an antiplasmodial activity of 1.66±0.54µg/ml on the 3D7 strain, and the same range of activity was observed for isolated isomers mixtures. This is the first report on the in vivo activity of K. leucantha extracts, the isolation of thirteen compounds and analysis of their antiplasmodial activity. The results obtained may partially justify the traditional use of K. leucantha to treat malaria in Benin.
    Journal of ethnopharmacology 06/2013; · 2.32 Impact Factor
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    ABSTRACT: Ethnopharmacological relevanceParastrephia lucida (Meyen) Cabrera is used in the traditional medicine of Argentinean highlands as an antiseptic and anti-inflammatory medicinal plant. To give scientific support to the ethnopharmacological claim of Parastrephia lucida as an anti-inflammatory crude drug the effect of Parastrephia lucida extracts and fractions was assessed on key enzymes of the biosynthesis of pro-inflammatory eicosanoids mediators from arachidonic acid (AA).Materials and methodsA bio-guided fractionation of the plant extract was carried out to find out the compounds or mixtures responsible for the anti-inflammatory effect. The extracts and fractions were tested in vitro for their ability to inhibit the enzymes cyclooxygenase (COX)-1 and COX-2, lipoxygenase (LOX) and phospholipase (sPLA2). Fractions were analyzed by HPLC–MS, HPLC–ESI-MS/MS and NMR to relate the effect with groups of secondary metabolites.ResultsParastrephia lucida was more effective inhibiting COX and sPLA2 than LOX. Assay-guided isolation led to the active fractions C and F which showed different effect on the selected enzymes. The fraction C was more effective inhibiting LOX while fraction F showed better activity against sPLA2 and COX-2. Both fractions were further worked-up following the isolation of the anti-inflammatory agents with the selected enzyme assays. The main compounds identified in the most active fractions were 5,4′-dihydroxi-7-methoxyflavanone, apigenin, apigenin methyl ether and apigenin trimethyl ether, methyl and dimethyl ethers from quercetin, kaempferol and luteolin methyl ether, ferulic acid esters, cinnamic acid and vanillin.Conclusions Parastrephia lucida extract inhibit AA metabolism via several enzymes. The results give support to the traditional use of this plant for the treatment of inflammatory disorders.
    Journal of ethnopharmacology 01/2013; 150(3):1080–1086. · 2.32 Impact Factor
  • Mariano Walter Pertino, Cristina Theoduloz, Marco Bastías, Guillermo Schmeda-Hirschmann
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    ABSTRACT: Several diterpenes with the labdane skeleton show biological activity, including antiproliferative effects. Most of the research work on bioactive labdanes has been carried out on naturally occurring diterpenes and semisynthetic derivatives, but much less is known on the effects of diterpene dimers. The aim of the present work was to synthesize dimeric diterpenes from the labdane imbricatolic acid using esters, ethers and the triazole ring as linkers. Some 18 new derivatives were prepared and the compounds were evaluated for antiproliferative activity on human normal fibroblasts (MRC-5) and the following human tumor cell lines: AGS, SK-MES-1, J82 and HL-60. The diethers 8-10, differing in the number of CH2 units in the linker, presented better antiproliferative activity with a maximum effect for the derivative 9. The best antiproliferative effect against HL-60 cells was found for compounds 3 and 17, with IC50 values of 22.3 and 23.2 μM, lower than that found for the reference compound etoposide (2.23 μM). The compounds 9, 17 and 11 were the most active derivatives towards AGS cells with IC50 values of 17.8, 23.4 and 26.1 μM. A free carboxylic acid function seems relevant for the effect as several of the compounds showed less antiproliferative effect after methylation.
    Molecules 01/2013; 18(5):5936-5953. · 2.43 Impact Factor
  • Cristina Theoduloz, Mariano Walter Pertino, Guillermo Schmeda-Hirschmann
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    ABSTRACT: Carnosic acid (CA) and its semisynthetic derivatives display relevant gastroprotective effects on HCl/ethanol induced gastric lesions in mice. However, little is known on the mechanisms of action of the new compounds. The aim of the present work was to assess the gastroprotective action mechanisms of CA and its derivatives using human cell culture models. A human gastric adenocarcinoma cell line (AGS) and lung fibroblasts (MRC-5) were used to reveal the possible mechanisms involved. The ability of the compounds to protect cells against sodium taurocholate (NaT)-induced damage, and to increase the cellular reduced glutathione (GSH) and prostaglandin E2 (PGE2) content was determined using AGS cells. Stimulation of cell proliferation was studied employing MRC-5 fibroblasts. Carnosic acid and its derivatives 10-18 raised GSH levels in AGS cells. While CA did not increase the PGE2 content in AGS cells, all derivatives significantly stimulated PGE2 synthesis, the best effect being found for the 12-O-indolebutyrylmethylcarnosate 13. A significant increase in MRC-5 fibroblast proliferation was observed for the derivatives 7 and 16-18. The antioxidant effect of the compounds was assessed by the inhibition of lipid peroxidation in human erythrocyte membranes, scavenging of superoxide anion and DPPH discoloration assay. The new CA derivatives showed gastroprotective effects by different mechanisms, including protection against cell damage induced by NaT, increase in GSH content, stimulation of PGE2 synthesis and cell proliferation.
    Molecules 01/2013; 19(1):581-94. · 2.43 Impact Factor
  • Mario J Simirgiotis, Guillermo Schmeda-Hirschmann, Jorge Bórquez, Edward J Kennelly
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    ABSTRACT: The banana passion fruit (Passiflora tripartita Breiter, Passifloraceae) known as "tumbo" is very appreciated in tropical and subtropical countries of South America. Methanolic extracts from peel and the fruit juice of P. tripartita growing in Chile were analyzed for antioxidant capacity as well as for flavonoid and phenolic content. A chromatographic method was developed for the rapid identification of the main phenolics in the samples by HPLC-DAD and HPLC-MS. The fast fingerprint analysis allowed the detection of eighteen flavonoid C-glycosides and four flavonoid O-glycoside derivatives which were characterized by UV spectra and ESI-MS-MS analysis. Several of the C-glycosides detected are structurally related to the orientin derivative 4'-methoxy-luteolin-8-C-(6″acetyl)-b-D-glucopyranoside (31), fully elucidated by spectroscopic methods. The antioxidant derivative 31 along with schaftoside, vicenin II, orientin and vitexin were isolated from the fruit extract by high-speed countercurrent chromatography (HSCCC). A suitable method for the preparative isolation of flavonol C-glycosides from "tumbo" extracts by HSCCC is reported. The pulp of the fruits showed good antioxidant capacity (12.89 ± 0.02 mg/mL in the DPPH assay). The peel presented the highest content of flavonoids (56.03 ± 4.34 mg quercetin/100 g dry weight) which is related to the highest antioxidant power (10.41 ± 0.01 mg/mL in the DPPH assay).
    Molecules 01/2013; 18(2):1672-92. · 2.43 Impact Factor
  • Mariano Walter Pertino, Cecilia Lopez, Cristina Theoduloz, Guillermo Schmeda-Hirschmann
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    ABSTRACT: Hybrid compounds are relevant products when searching for structure-activity relationships of natural products. Starting from the naturally occurring triterpene oleanolic acid, alkyl esters were prepared and treated with different aromatic azides using click chemistry to produce hybrid compounds. Some 18 new oleanolic acid derivatives were synthesized and the structures were confirmed by spectroscopic and spectrometric means. The antiproliferative activity of the new derivatives was evaluated towards normal lung fibroblasts (MRC-5), gastric epithelial adenocarcinoma (AGS), promyelocytic leukemia (HL-60), lung cancer (SK-MES-1) and bladder carcinoma (J82) cells. The alkyne esters 1 and 3 showed activity on all cell lines but without selectivity (19.6-23.1 μM and 14.1-56.2 μM, respectively), their respective methyl esters were inactive. Compounds with a benzene and p-anisole attached to the triazole ring, showed no antiproliferative effect. Introduction of a chlorine atom into the benzene ring (compound 9) elicited a selective effect against AGS cells (IC50 value: 8.9 μM). The activity was lost when the COOH function at C-28 was methylated. Better antiproliferative effect was found for compounds 11 and 15 bearing a p-toluenesulphonyl group, with values in the range of 10.8-47.1 μM and 11.5-22.2 μM, respectively. The effect, however, was not associated with selectivity.
    Molecules 01/2013; 18(7):7661-74. · 2.43 Impact Factor
  • Cristina Theoduloz, Ivanna Bravo, Mariano Walter Pertino, Guillermo Schmeda-Hirschmann
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    ABSTRACT: A modern approach in the search for new bioactive molecules is the synthesis of novel chemical entities combining molecules of different biosynthetic origin presenting biological effects as single compounds. Gastroprotective compounds from South American medicinal plants, namely quinones and diterpenes, were used as building blocks to obtain hybrid diterpenylquinones. Starting from the labdane diterpene junicedric acid and two isomers, as well as from three quinones, including lapachol, 18 hybrid molecules were synthesized. Six of them are described for the first time. The potential gastroprotective mechanisms of action of the compounds were assessed in dose-response experiments using human gastric epithelial cells (AGS) and human lung fibroblasts (MRC-5). The following studies were carried out: stimulation of cell proliferation, cytoprotection against sodium taurocholate (NaT)-induced damage, synthesis of PGE2 and total reduced sulfhydryl (GSH) content. The antioxidant capacity of the compounds was determined on the inhibition of the lipoperoxidation in human erythrocyte membranes. Hybrid compounds presented activities different from those shown by the starting compounds, supporting the potential of this approach in the search for new bioactive molecules. The effects might be modulated by selective modification in the terpene or quinone moieties of the new molecules. Structure-activity relationships are discussed.
    Molecules 01/2013; 18(9):11044-66. · 2.43 Impact Factor
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    ABSTRACT: The stem bark of Tabebuia species and the rhizomes of Jatropha isabelii are used in Paraguayan traditional medicine to treat gastric lesions and as anti-inflammatory agents. The sesquiterpene cyperenoic acid obtained from J. isabelii has been shown to display a gastroprotective effect in animal models of induced gastric ulcers while the quinone lapachol shows several biological effects associated with the use of the crude drug. The aim of this work was to prepare hybrid molecules presenting a terpene and a quinone moiety and to obtain an assessment of the gastroprotective activity of the new compounds using human cell cultures (MRC-5 fibroblasts and AGS epithelial gastric cells). Eight compounds, including the natural products and semisynthetic derivatives were assessed for proliferation of MRC-5 fibroblasts, protection against sodium taurocholate-induced damage, prostaglandin E2 content, and stimulation of cellular-reduced glutathione synthesis in AGS cells. The following antioxidant assays were performed: DPPH discoloration, scavenging of the superoxide anion, and inhibition of induced lipoperoxidation in erythrocyte membranes. 3-Hydroxy-β-lapachone (3) and cyperenoic acid (4) stimulated fibroblast proliferation. Lapachol (1), dihydroprenyl lapachol (2), 3-hydroxy-β-lapachone (3), and lapachoyl cyperenate (6) protected against sodium taurocholate-induced damage in AGS cells. Lapachol (1) and dihydroprenyl lapachoyl cyperenate (7) significantly stimulated prostaglandin E2 synthesis in AGS cells. Compounds 3, 4, and 7 raised reduced glutathione levels in AGS cells. The hybrid compounds presented activities different than those of the starting sesquiterpene or quinones.
    Planta Medica 10/2012; · 2.35 Impact Factor
  • Cristina Quispe, Ezequiel Viveros-Valdez, Guillermo Schmeda-Hirschmann
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    ABSTRACT: "Pichi" or "pichi romero" (Fabiana imbricata R. et. P., Solanaceae) is a Chilean plant used as a tea in the Andean regions of Chile and Argentina. A very simple and direct method was developed for the qualitative analysis of polyphenols in the tea by high-performance liquid chromatography (HPLC) with diode array detection and electrospray ionization tandem mass spectrometry. The phenolic constituents identified in the teas were chlorogenic acid (3-O-caffeoylquinic acid), p-hydroxyacetophenone, scopoletin and quercetin derivatives. The glycosides were mainly glucosides from p-hydroxyacetophenone and scopoletin while di- and tri-glycosides from quercetin were the main flavonoids. The content of the main phenolic compounds in the teas (g/100 g lyophilized infusion) was 0.8-1.9 % for scopoletin, 0.4-6.2 % for p-hydroxyacetophenone and 2.1-4.3 % for rutin, respectively. The health-promoting properties reported for this herbal tea can be associated with the presence of several phenolics with known antioxidant, diuretic and antiinflammatory activity.
    Plant Foods for Human Nutrition 08/2012; 67(3):242-6. · 2.36 Impact Factor
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    ABSTRACT: The Argentinean highland plant Parastrephia lucida (Meyen) Cabrera is used in traditional medicine as an antiseptic and anti-inflammatory crude drug. To relate the antimicrobial effect of the crude drug with the constituents of the active fractions and traditional use. Assay-guided isolation of the methanol (MeOH) plant extract was carried out using bacteria and yeasts as target organisms. Both ATCC and local strains were included in the study. The antimicrobial fractions and compounds were detected by bioautographic assays. Minimum inhibitory concentrations (MIC) of each extract and fraction were determined and compared with reference antibiotics. Fractions were analyzed by HPLC-DAD, GC-MS, (1)H NMR and (13)C NMR. From the MeOH extract of the plant, assay-guided isolation of the antimicrobial constituents led to 12 phenylpropanoids and two simple phenolics. Most of the compounds occurring in the active fractions were E-caffeoyl or E-cinnamoyl esters including prenyl and phenethyl derivatives. The MIC values of the most active fractions ranged between 12.5 and 200 μg/mL against reference strains and local isolates of Staphylococcus aureus and Enterococcus faecalis. The antimicrobial effect found in the crude drug was associated with mixtures of phenylpropanoids, including prenyl and phenethyl esters of caffeic and cinnamic acids. The results support at least in part the traditional use of the plant as local antiseptic.
    Journal of ethnopharmacology 07/2012; 142(2):407-14. · 2.32 Impact Factor
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    ABSTRACT: The correction of patented structure 1 of rosmaridiphenol, an antioxidant isolated from rosemary, Rosmarinus officinalis, was made recently. The correct structure is proposed as 11,12-dihydroxy-8,11,13-icetexatrien-1-one (2a) based on 2D NMR data. In order to further support the structure, this work reports the single-crystal X-ray analysis, the complete (1)H NMR assignment by full spin-spin simulation, and the absolute configuration of the diacetate 2b derived via vibrational circular dicroism measurements in comparison with density functional theory calculated data.
    Journal of Natural Products 03/2012; 75(4):779-83. · 3.29 Impact Factor
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    ABSTRACT: Starting from the diterpene (4S,9R,10R) methyl 18-carboxy-labda-8,13(E)-dien-15-oate (PMD) and its 8(9)-en isomer [PMD 8(9)-en], 11 amides were prepared and assessed for a gastroprotective effect in the ethanol/HCl-induced gastric lesions model in mice. Basal cytotoxicity of the compounds was determined on the following human cell lines: normal lung fibroblasts (MRC-5), gastric epithelial adenocarcinoma (AGS), and hepatocellular carcinoma (Hep G2). All compounds are described for the first time. At the single oral dose of 0.1 mg/kg, compounds 1, 10, and 11 presented a strong gastroprotective effect, at least comparable with that of the reference compound lansoprazole at 1 mg/kg, reducing gastric lesions by 76.7, 67.7, and 77.2 %, respectively. The leucyl amide methyl ester 3, tryptophanyl amide methyl ester 5, and benzyl amide 6 of PMD presented a selective basal cytotoxicity on Hep G2 cells with IC₅₀ values of 136.8, 105.3, and 94.2 µM, respectively, while the IC₅₀ values towards AGS cells were 439.5, 928.0, and 937.3 µM, respectively. The three compounds did not affect fibroblast viability with IC₅₀ values > 1000 µM. Compounds 7, 8, 10, and 11 showed no toxic effect against the three selected cell lines.
    Planta Medica 03/2012; 78(4):362-7. · 2.35 Impact Factor

Publication Stats

942 Citations
287.23 Total Impact Points


  • 1991–2014
    • Universidad de Talca
      • • Insitute of Chemestry of Natural Resources
      • • Departamento de Ciencias Básicas Biomédicas
      Talca, Maule, Chile
  • 2013
    • Universidad Nacional San Cristóbal de Huamanga
      Ayacucho, Ayacucho Region, Peru
  • 2006
    • Pontifical Catholic University of Chile
      • Facultad de Química
      Santiago, Region Metropolitana de Santiago, Chile
  • 1986–2006
    • Universidad Nacional de Asunción
      • Facultad de Ciencias Químicas
      San Lorenzo del Campo Grande, Central, Paraguay
  • 2000–2003
    • National University of San Juan
      • Instituto de Ciencias Básicas (ICB)
      San Juan, Provincia de San Juan, Argentina
    • Universidade Federal de Mato Grosso (UFMT)
      Vila Real do Senhor Bom Jesus de Cuiabá, Mato Grosso, Brazil
  • 1999
    • Universidad Nacional de Jujuy
      • Facultad de Ingeniería
      Jujuy, Jujuy, Argentina
  • 1984–1988
    • Technische Universität Berlin
      • Division of Organic Chemistry
      Berlin, Land Berlin, Germany