Publications by authors named "Serge Lavoie"

31 Publications

Total synthesis, isolation, surfactant properties, and biological evaluation of ananatosides and related macrodilactone-containing rhamnolipids.

Chem Sci 2021 May 4;12(21):7533-7546. Epub 2021 May 4.

Centre Armand-Frappier Santé Biotechnologie, Institut National de la Recherche Scientifique (INRS) 531, Boulevard des Prairies Laval (Québec) H7V 1B7 Canada

Rhamnolipids are a specific class of microbial surfactants, which hold great biotechnological and therapeutic potential. However, their exploitation at the industrial level is hampered because they are mainly produced by the opportunistic pathogen . The non-human pathogenic bacterium is an alternative producer of rhamnolipid-like metabolites containing glucose instead of rhamnose residues. Herein, we present the isolation, structural characterization, and total synthesis of ananatoside A, a 15-membered macrodilactone-containing glucolipid, and ananatoside B, its open-chain congener, from organic extracts of . Ananatoside A was synthesized through three alternative pathways involving either an intramolecular glycosylation, a chemical macrolactonization or a direct enzymatic transformation from ananatoside B. A series of diasteroisomerically pure (1→2), (1→3), and (1→4)-macrolactonized rhamnolipids were also synthesized through intramolecular glycosylation and their anomeric configurations as well as ring conformations were solved using molecular modeling in tandem with NMR studies. We show that ananatoside B is a more potent surfactant than its macrolide counterpart. We present evidence that macrolactonization of rhamnolipids enhances their cytotoxic and hemolytic potential, pointing towards a mechanism involving the formation of pores into the lipidic cell membrane. Lastly, we demonstrate that ananatoside A and ananatoside B as well as synthetic macrolactonized rhamnolipids can be perceived by the plant immune system, and that this sensing is more pronounced for a macrolide featuring a rhamnose moiety in its native conformation. Altogether our results suggest that macrolactonization of glycolipids can dramatically interfere with their surfactant properties and biological activity.
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http://dx.doi.org/10.1039/d1sc01146dDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8171317PMC
May 2021

Development and characterisation of a nanostructured hybrid material with vitamin B12 and bagasse-derived activated carbon for anaerobic chlordecone (Kepone) removal.

Environ Sci Pollut Res Int 2020 Nov 30;27(33):41122-41131. Epub 2020 Mar 30.

Laboratoire COVACHIM-M2E, EA 3592, Université des Antilles, BP 250, 97157 Cedex, Pointe-à-Pitre, Guadeloupe, France.

Intensive use of the chlorinated pesticide chlordecone from the 1970s to 1993 to prevent crop damage in banana plantations of Guadeloupe and Martinique led to diffuse pollution of soils and surface waters, affecting both fauna and human beings in the contaminated areas. Since 2001, drinking water production plants have been equipped with filters containing activated carbon that must be treated after saturation. The objective of this work is to produce a hybrid material composed of activated carbon and vitamin B12 (VB12) for the degradation of chlordecone (CLD). The preparation of such a hybrid material is carried out by non-covalent fixation to achieve an eco-friendly solution for the serious environmental problem of contamination by chlorinated pesticides. It is thus proposed to degrade CLD by a physico-chemical treatment allowing salvage of the catalyst, which is adsorbed on the carbon surface to generate less waste that is inexpedient to treat. Activated carbon (AC) is produced locally from available sugarcane bagasse subjected to phosphoric acid activation. The main characteristics of this material are a major mesoporous structure (0.91%) and a specific (BET) surface area ranging from 1000 to 1500 m g. The experimental results showed that BagP1.5 has a high adsorption capacity for VB12 due to its large surface area (1403 m g). The binding of VB12 to the bagasse-derived AC is favoured at high temperatures. The adsorption is optimal at a pH of approximately 6. The maximum adsorption capacity of VB12 on the AC, deduced from the Langmuir model, was 306 mg g, confirming the high affinity between the two components. The hybrid material was characterised by FTIR, Raman, X-ray fluorescence spectroscopy and SEM analysis. CLD removal by this hybrid material was faster than that by VB12 or BagP1.5 alone. The CLD degradation products were characterised by mass spectrometry.
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http://dx.doi.org/10.1007/s11356-020-08201-9DOI Listing
November 2020

Peyssonnosides A-B, Unusual Diterpene Glycosides with a Sterically Encumbered Cyclopropane Motif: Structure Elucidation Using an Integrated Spectroscopic and Computational Workflow.

J Org Chem 2019 07 18;84(13):8531-8541. Epub 2019 Jun 18.

Parker H. Petit Institute for Bioengineering and Bioscience , Georgia Institute of Technology , Atlanta , Georgia 30332 , United States.

Two sulfated diterpene glycosides featuring a highly substituted and sterically encumbered cyclopropane ring have been isolated from the marine red alga Peyssonnelia sp. Combination of a wide array of 2D NMR spectroscopic experiments, in a systematic structure elucidation workflow, revealed that peyssonnosides A-B (1-2) represent a new class of diterpene glycosides with a tetracyclo [7.5.0.0.0] tetradecane architecture. A salient feature of this workflow is the unique application of quantitative interproton distances obtained from the rotating frame Overhauser effect spectroscopy (ROESY) NMR experiment, wherein the β-d-glucose moiety of 1 was used as an internal probe to unequivocally determine the absolute configuration, which was also supported by optical rotatory dispersion (ORD). Peyssonnoside A (1) exhibited promising activity against liver stage Plasmodium berghei and moderate antimethicillin-resistant Staphylococcus aureus (MRSA) activity, with no cytotoxicity against human keratinocytes. Additionally, 1 showed strong growth inhibition of the marine fungus Dendryphiella salina indicating an antifungal ecological role in its natural environment. The high natural abundance and novel carbon skeleton of 1 suggests a rare terpene cyclase machinery, exemplifying the chemical diversity in this phylogenetically distinct marine red alga.
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http://dx.doi.org/10.1021/acs.joc.9b00884DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6614789PMC
July 2019

Antibacterial Oligomeric Polyphenols from the Green Alga Cladophora socialis.

J Org Chem 2019 05 3;84(9):5035-5045. Epub 2019 Apr 3.

Aquatic Chemical Ecology Center , Georgia Institute of Technology , Atlanta , Georgia 30332 , United States.

A series of oligomeric phenols including the known natural product 3,4,3',4'-tetrahydroxy-1,1'-biphenyl (3), the previously synthesized 2,3,8,9-tetrahydroxybenzo[ c]chromen-6-one (4), and eight new related natural products, cladophorols B-I (5-12), were isolated from the Fijian green alga Cladophora socialis and identified by a combination of NMR spectroscopy, mass spectrometric analysis, and computational modeling using DFT calculations. J-resolved spectroscopy and line width reduction by picric acid addition aided in resolving the heavily overlapped aromatic signals. A panel of Gram-positive and Gram-negative pathogens used to evaluate pharmacological potential led to the determination that cladophorol C (6) exhibits potent antibiotic activity selective toward methicillin-resistant Staphylococcus aureus (MRSA) with an MIC of 1.4 μg/mL. Cladophorols B (5) and D-H (7-11) had more modest but also selective antibiotic potency. Activities of cladophorols A-I (4-12) were also assessed against the asexual blood stages of Plasmodium falciparum and revealed cladophorols A (4) and B (5) to have modest activity with EC values of 0.7 and 1.9 μg/mL, respectively.
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http://dx.doi.org/10.1021/acs.joc.8b03218DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6503470PMC
May 2019

Structural determination of ananatoside A: An unprecedented 15-membered macrodilactone-containing glycolipid from Pantoea ananatis.

Carbohydr Res 2019 Jan 28;471:13-18. Epub 2018 Oct 28.

INRS - Institut Armand-Frappier, Université du Québec, 531, boul. des Prairies, Laval, Québec, H7V 1B7, Canada. Electronic address:

The bacterium Pantoea ananatis was reported to produce glycolipid biosurfactants of unknown structures. Herein, we present the isolation and structural determination of ananatoside A, the main congener of a new family of 15-membered macrodilactone-containing glucolipids. The structure of ananatoside A was elucidated via chemical degradation and spectroscopic methods including 1D/2D NMR analysis, tandem MS/MS, GC-MS, HR-ESI-TOF-MS, MALDI-TOF-MS, and polarimetry. Computational methods were used to predict the most abundant conformers of ananatoside A.
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http://dx.doi.org/10.1016/j.carres.2018.10.009DOI Listing
January 2019

Correction: Recent trends in the structural revision of natural products.

Nat Prod Rep 2018 09;35(9):1015

School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, GA 30332, USA.

Correction for 'Recent trends in the structural revision of natural products' by Bhuwan Khatri Chhetri et al., Nat. Prod. Rep., 2018, 35, 514-531.
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http://dx.doi.org/10.1039/c8np90031kDOI Listing
September 2018

Recent trends in the structural revision of natural products.

Nat Prod Rep 2018 06;35(6):514-531

School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, GA 30332, USA.

Covering: 2012 to 2017 This article reviews recent reports on the structural revision of natural products. Through a critical assessment of the original and revised published structures, the article addresses why each structure was targeted for revision, discusses the techniques and key discrepancies that led to the proposal of the revised structure, and offers measures that may have been taken during the original structure determination to prevent error. With the revised structures in hand, weaknesses of original proposals are assessed, providing a better understanding on the logic behind structure determination.
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http://dx.doi.org/10.1039/c8np00011eDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6013367PMC
June 2018

Chemical encoding of risk perception and predator detection among estuarine invertebrates.

Proc Natl Acad Sci U S A 2018 01 8;115(4):662-667. Epub 2018 Jan 8.

School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, GA 30332;

An effective strategy for prey to survive in habitats rich in predators is to avoid being noticed. Thus, prey are under selection pressure to recognize predators and adjust their behavior, which can impact numerous community-wide interactions. Many animals in murky and turbulent aquatic environments rely on waterborne chemical cues. Previous research showed that the mud crab, , recognizes the predatory blue crab, , via a cue in blue crab urine. This cue is strongest if blue crabs recently preyed upon mud crabs. Subsequently, mud crabs suppress their foraging activity, reducing predation by blue crabs. Using NMR spectroscopy- and mass spectrometry-based metabolomics, chemical variation in urine from blue crabs fed different diets was related to prey behavior. We identified the urinary metabolites trigonelline and homarine as components of the cue that mud crabs use to detect blue crabs, with concentrations of each metabolite dependent on the blue crab's diet. At concentrations found naturally in blue crab urine, trigonelline and homarine, alone as well as in a mixture, alerted mud crabs to the presence of blue crabs, leading to decreased foraging by mud crabs. Risk perception by waterborne cues has been widely observed by ecologists, but the molecular nature of these cues has not been previously identified. Metabolomics provides an opportunity to study waterborne cues where other approaches have historically failed, advancing our understanding of the chemical nature of a wide range of ecological interactions.
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http://dx.doi.org/10.1073/pnas.1713901115DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5789921PMC
January 2018

Iodinated Meroditerpenes from a Red Alga Callophycus sp.

J Org Chem 2017 04 13;82(8):4160-4169. Epub 2017 Apr 13.

School of Chemistry and Biochemistry and ‡School of Biological Sciences, Aquatic Chemical Ecology Center, Institute for Bioengineering and Bioscience, Georgia Institute of Technology , Atlanta, Georgia 30332, United States.

Unique iodine-containing meroditerpenes iodocallophycoic acid A (1) and iodocallophycols A-D (2-5) were discovered from the Fijian red alga Callophycus sp. Because flexibility of the molecular skeleton impaired full characterization of relative stereochemistries by NMR spectroscopy, a DFT-based theoretical model was developed to derive relevant interproton distances which were compared to those calculated from NOE measurements, yielding the relative stereochemistries. The correct 2S,6S,7S,10S,14S enantiomers were then identified by comparison of theoretical and experimental ECD spectra. Biological activities of these iodinated and brominated meroditerpenes and additional new, related bromophycoic acid F (6) and bromophycoic acid A methyl ester (7), were evaluated for relevant human disease targets. Iodocallophycoic acid A (1) showed moderate antibiotic activity against methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant Enterococcus faecium (VREF) with MIC values of 1.4 and 2.2 μg mL, respectively. It also potentiated the anti-MRSA activity of oxacillin in a synergistic fashion, resulting in an 8-fold increase in oxacillin potency, for a MIC of 16 μg mL.
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http://dx.doi.org/10.1021/acs.joc.7b00096DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5538829PMC
April 2017

Chemical composition and anti-herpes simplex virus type 1 (HSV-1) activity of extracts from Cornus canadensis.

BMC Complement Altern Med 2017 Feb 22;17(1):123. Epub 2017 Feb 22.

Laboratoire LASEVE, Département des Sciences Fondamentales, Université du Québec à Chicoutimi, 555 boul. de l'Université, Chicoutimi, Québec, G7H 2B1, Canada.

Background: Many plants of boreal forest of Quebec have been used by Native Americans to treat a variety of microbial infections. However, the antiviral activities of these plants have been seldom evaluated on cellular models to validate their in vitro efficiencies. In this study, Cornus canadensis L. (Cornaceae), a plant used in Native American traditional medicine to treat possible antiviral infections, has been selected for further examination.

Methods: The plant was extracted by decoction and infusion with water, water/ethanol 1:1 and ethanol to obtain extracts similar to those used by Native Americans. The effects of the extracts were tested on herpes simplex virus type-1 (HSV-1) using a plaque reduction assay. Moreover, bioassay-guided fractionation was achieved to isolate bioactive compounds.

Results: Water/ethanol 1:1 infusion of C. canadensis leaves were the most active extracts to inhibit virus absorption with EC of about 9 μg mL, whereas for direct mode, both extraction methods using water or water/ethanol 1:1 as solvent were relatively similar with EC ranging from 11 to 17 μg mL. The fractionation led to the identification of active fractions containing hydrolysable tannins. Tellimagrandin I was found the most active compound with an EC of 2.6 μM for the direct mode and 5.0 μM for the absorption mode.

Conclusion: Altogether, the results presented in this work support the antiviral activity of Cornus canadensis used in Native American traditional medicine.
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http://dx.doi.org/10.1186/s12906-017-1618-2DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5322616PMC
February 2017

4'-Methoxyphenacyl-Assisted Synthesis of β-Kdo Glycosides.

J Org Chem 2016 11 20;81(22):10585-10599. Epub 2016 Sep 20.

Institut de Chimie IC2MP, CNRS-UMR 7285, Équipe Synthèse Organique, Université de Poitiers , 4 rue Michel Brunet, 86073 Poitiers Cedex 9, France.

3-Deoxy-β-d-manno-oct-2-ulosonic acid (β-Kdo) glycosides are mainly found in capsular polysaccharides and extracellular exopolysaccharides from Gram-negative bacteria. These compounds have profound biological implications in immune response and act as virulence factors. We have developed a novel methodology for the stereoselective synthesis of β-Kdo glycosides via the use of a 4'-methoxyphenacyl (Phen) auxiliary group at the C1 position of a peracetylated β-Kdo thioglycoside. Under the promotion of NIS/AgOTf in acetonitrile, a series of Kdo glycosides was synthesized in good yield and β-selectivity while minimizing the formation of undesirable glycals. Stereoselectivity of the glycosylation was shown to be modulated by various factors such as promotor, solvent, anomeric ratio of donor, nature of acceptor, and Phen substitution. Chemoselective cleavage of the Phen group was performed under the action of Zn/HOAc. DFT calculations together with experimental results suggested that α-triflate and a six-membered α-spiroPhen are plausible intermediates of the reaction, accounting for the enhanced formation of β-Kdo glycosides. The developed methodology could be applied to the synthesis of β-Kdo-containing glycans from pathogenic bacteria.
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http://dx.doi.org/10.1021/acs.joc.6b01431DOI Listing
November 2016

Structure elucidation of anti-methicillin resistant Staphylococcus aureus (MRSA) flavonoids from balsam poplar buds.

Bioorg Med Chem 2016 09 6;24(18):4188-4198. Epub 2016 Jul 6.

Laboratoire LASEVE, Département des Sciences Fondamentales, Université du Québec à Chicoutimi, 555, boul. de l'Université, Chicoutimi (Québec) G7H 2B1, Canada. Electronic address:

There is nowadays an urgent need for developing novel generations of antibiotic agents due to the increased resistance of pathogenic bacteria. As a rich reservoir of structurally diverse compounds, plant species hold promise in this regard. Within this framework, we isolated a unique series of antibacterial flavonoids, named balsacones N-U, featuring multiple cinnamyl chains on the flavan skeleton. The structures of these compounds, isolated as racemates, were determined using extensive 1D and 2D NMR analysis in tandem with HRMS. Balsacones N-U along with previously isolated balsacones A-M were evaluated for their antibacterial activity against clinical isolates of methicillin resistant Staphylococcus aureus (MRSA). Several of the tested balsacones were potent anti-MRSA agents showing MIC values in the low micromolar range. Structure-activity relationships study highlighted some important parameters involved in the antibacterial activity of balsacones such as the presence of cinnamyl and cinnamoyl chains at the C-3 and C-8 positions of the flavan skeleton, respectively. These results suggest that balsacones could represent a potential novel class of naturally occurring anti-MRSA agents.
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http://dx.doi.org/10.1016/j.bmc.2016.07.009DOI Listing
September 2016

DFT Calculations and ROESY NMR Data for the Diastereochemical Characterization of Cytotoxic Tetraterpenoids from the Oleoresin of Abies balsamea.

J Nat Prod 2015 Dec 23;78(12):2896-907. Epub 2015 Nov 23.

Chaire de Recherche sur les Agents Anticancéreux d'Origine Naturelle, Laboratoire LASEVE, Département des Sciences Fondamentales, Université du Québec à Chicoutimi , 555 Boulevard de l'Université, Chicoutimi, Québec, Canada , G7H 2B1.

Eight non-carotenoid tetraterpenoids, abibalsamins C-J (3-10), were isolated from the oleoresin of Abies balsamea. Their chemical structures were determined based on analysis of 1D/2D NMR and MS data. The assignment of their relative configurations was accomplished using homonuclear coupling constants in tandem with ROESY data. However, the presence of two stereogenic centers on a flexible side chain complicated the characterization. In silico models and ROESY data were analyzed in order to assign relative configurations of the isolated tetraterpenoids. Abibalsamins B and H-J showed moderate cytotoxicity against human A549 lung carcinoma cells, with IC50 values ranging between 6.7 and 10 μM.
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http://dx.doi.org/10.1021/acs.jnatprod.5b00492DOI Listing
December 2015

Complete (1)H and (13)C NMR assignments of a series of pergalloylated tannins.

Magn Reson Chem 2016 Feb 9;54(2):168-74. Epub 2015 Sep 9.

Chaire de Recherche sur les Agents Anticancéreux d'Origine Naturelle, Laboratoire LASEVE, Département des Sciences Fondamentales, Université du Québec à Chicoutimi, 555 boul. de l'Université, Chicoutimi, Québec, G7H 2B1, Canada.

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http://dx.doi.org/10.1002/mrc.4328DOI Listing
February 2016

Antibacterial Balsacones J-M, Hydroxycinnamoylated Dihydrochalcones from Populus balsamifera Buds.

J Nat Prod 2015 May 30;78(5):1147-53. Epub 2015 Apr 30.

†Chaire de Recherche sur les Agents Anticancéreux d'Origine Naturelle, Laboratoire LASEVE, Département des Sciences Fondamentales, Université du Québec à Chicoutimi, 555 Boulevard de l'Université, Chicoutimi, Québec, Canada, G7H 2B1.

A phytochemical investigation of buds from the hardwood tree Populus balsamifera led to the isolation of six new cinnamoylated dihydrochalcones as pairs of racemates and one as a racemic mixture along with the known compound iryantherin-D (2), the absolute configuration of which was determined for the first time. The structures of balsacones J (1), K (3), L (4), and M (5) were elucidated on the basis of spectroscopic data (1D and 2D NMR, IR, and MS). Chiral HPLC separations were carried out, and the absolute configuration of the isolated enantiomers unambiguously established via X-ray diffraction analyses and electron circular dichroism spectroscopic data. Each of the purified enantiomers exhibited potent in vitro antibacterial activity against Staphylococcus aureus with IC50 values ranging from 0.61 to 6 μM.
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http://dx.doi.org/10.1021/acs.jnatprod.5b00155DOI Listing
May 2015

Isolation of a new disaccharide nucleoside from Helleborus caucasicus: structure elucidation and total synthesis of hellecaucaside A and its β-anomer.

Carbohydr Res 2014 Oct 1;398:80-9. Epub 2014 Jul 1.

Université du Québec à Chicoutimi, Chaire de recherche sur les agents anticancéreux d'origine naturelle, Laboratoire LASEVE, Département des sciences fondamentales, 555 boul. de l'Université, Chicoutimi (Québec) G7H 2B1, Canada. Electronic address:

Hellecaucaside A, a new disaccharide nucleoside featuring a 2'-O-α-D-ribofuranosyluridine skeleton and a 4-hydroxybenzoyl group at the 5' position, was isolated from the underground part of Helleborus caucasicus. The structure of the compound was elucidated by means of chemical degradation and spectroscopic analyses, such as 1D/2D NMR, chiral-GC, and HRMS. The total synthesis of hellecaucaside A and its β-anomer was accomplished, unequivocally confirming the structure of the natural product.
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http://dx.doi.org/10.1016/j.carres.2014.06.027DOI Listing
October 2014

A new flavonol glycoside from the medicinal halophyte Suaeda fruticosa.

Nat Prod Res 2014 19;28(13):960-6. Epub 2014 Jun 19.

a Laboratoire des Plantes Extrêmophiles, Centre de Biotechnologie à la Technopôle de Borj-Cédria (CBBC) , BP 901, 2050 Hammam-Lif , Tunisia.

A new flavonol glycoside, namely 3-(α-rhamnopyranosyl-(1 → 2)-[β-xylopyranosyl-(1 → 6)]-β-glucopyranosyloxy) isorhamnetin was reported from methanol extracts of aerial parts of Suaeda fruticosa for the first time. In this work, liquid chromatography coupled to atmospheric pressure chemical ionisation mass spectrometry, high-resolution mass spectrometry and nuclear magnetic resonance spectroscopy were used to identify this new compound. Structure was elucidated on the basis of extensive spectroscopic analysis, including HSQC, HMBC and (1)H-(1)H COSY. Antioxidant potentialities of a pure compound were evaluated. The estimation of antioxidant capacities using oxygen radical absorbance capacity (ORAC method) and a cell based-assay (WS1) indicated that this new flavonol exhibited the highest antioxidant activities with an ORAC value of 5.0 ± 0.3 μmol Trolox/μmol and inhibited the tBH-induced oxidation of 2',7'-dichlorofluorescin with an IC50 value of 4.9 ± 0.6 μM.
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http://dx.doi.org/10.1080/14786419.2014.900771DOI Listing
November 2014

Balsacones D-I, dihydrocinnamoyl flavans from Populus balsamifera buds.

Phytochemistry 2014 Apr 30;100:141-9. Epub 2014 Jan 30.

Laboratoire d'Analyse et de Séparation des Essences Végétales (LASEVE), Département des sciences fondamentales, Université du Québec à Chicoutimi, Québec G7H 2B1, Canada. Electronic address:

A phytochemical investigation of an ethanolic extract from Populus balsamifera L. buds resulted in the isolation and characterization of twelve new flavan derivatives consisting of six pairs of enantiomers. Structures of (+) and (-)-balsacones D-I were elucidated based on spectroscopic data (1D and 2D NMR, MS) and their absolute configurations were established using X-ray single crystal diffraction analysis and ECD computational calculations. Antibacterial activity and cytotoxicity of all purified enantiomers were evaluated in vitro against Staphylococcus aureus and human skin fibroblast cells, respectively.
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http://dx.doi.org/10.1016/j.phytochem.2013.12.018DOI Listing
April 2014

Lanostane- and cycloartane-type triterpenoids from Abies balsamea oleoresin.

Beilstein J Org Chem 2013 4;9:1333-1339. Epub 2013 Jul 4.

Université du Québec à Chicoutimi, Chaire de Recherche sur les Agents Anticancéreux d'Origine Végétale, Laboratoire d'Analyse et de Séparation des Essences Végétales (LASEVE), Département des Sciences Fondamentales, 555 boul. de l'Université, Chicoutimi (Québec) G7H 2B1, Canada.

Phytochemical analysis of A. balsamea oleoresin led to the isolation of three new 3,4-seco-lanostane triterpenoids 1-3, one new cycloartane triterpenoid 4 along with fourteen known terpenoids. Structure determinations were based on extensive 1D/2D NMR, IR and MS spectroscopic analyses, and comparison with literature data. The isolated compounds were evaluated in vitro for their cytotoxicity against human cell lines (A549, DLD-1, WS1) and their antibacterial activity against E. coli and S. aureus. Abiesonic acid (6) exhibited weak cytotoxic activity against A549 (IC50 = 22 µM) while compounds 1 and 4 were weakly active against S. aureus (MIC = 25 µM).
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http://dx.doi.org/10.3762/bjoc.9.150DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3740800PMC
August 2013

Diterpenoids from the buds of Pinus banksiana Lamb.

Molecules 2012 Aug 13;17(8):9716-27. Epub 2012 Aug 13.

Département des Sciences Fondamentales, Chaire de Recherche sur les Agents Anticancéreux d'Origine Naturelle, Université du Québec à Chicoutimi, Québec G7H 2B1, Canada.

Three new diterpenoids, namely 7α-hydroxyabieta-8,11,13,15-tetraen-18-oic acid, 7β,15,18-trihydroxyabieta-8,11,13-triene, 13,15-dihydroxypodocarpa-8,11,13-triene, and 12 other known compounds were isolated from buds of Pinus banksiana Lamb. All these compounds, except for 7-oxodehydroabietinol, were isolated for the first time from this plant. Their structures were elucidated by detailed spectroscopic studies and comparison with published data. All isolated compounds were tested for cytotoxic and antibacterial activities. Overall, two compounds, 7-oxodehydroabietinol and 18-nor-4,15-dihydroxyabieta-8,11,13-trien-7-one, showed moderate cytotoxicity against a human lung carcinoma cell line.
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http://dx.doi.org/10.3390/molecules17089716DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6268314PMC
August 2012

Abibalsamins A and B, two new tetraterpenoids from Abies balsamea oleoresin.

Org Lett 2012 Mar 7;14(6):1504-7. Epub 2012 Mar 7.

Université du Québec à Chicoutimi, Laboratoire d'Analyse et de Séparation des Essences Végétales (LASEVE), Département des Sciences Fondamentales, 555 boul. de l'Université, Chicoutimi (Québec), Canada, G7H 2B1.

Abibalsamins A (1) and B (2), two unprecedented tetraterpenoids featuring a 3,4-seco-rearranged lanostane system fused with a β-myrcene lateral chain via a [4 + 2] Diels-Alder cycloaddition, were isolated from the oleoresin of Abies balsamea. Their structures were elucidated by means of extensive 2D NMR, IR, and MS spectroscopy analyses. The absolute configuration of 1 was determined by single-crystal X-ray diffraction. Both compounds exhibited significant cytotoxic activity against cancer cell lines.
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http://dx.doi.org/10.1021/ol300237fDOI Listing
March 2012

Cytotoxic activity of withanolides isolated from Tunisian Datura metel L.

Phytochemistry 2011 Nov 16;72(16):2031-6. Epub 2011 Aug 16.

Aromatic and Medicinal Plants Unit, Biotechnological Center in Borj-Cedria Techno-park, 901 Hammam-Lif, Tunisia.

Withanolide-type steroids, withametelin Q (1) and 12α-hydroxydaturametelin B (2) along with three known withanolides, were isolated from leaves of Datura metel L. (Solanaceae). The respective structures, characterized mainly by NMR spectroscopy, were identified as (20R,22R,24R)-21,24-epoxy-1α,3β-dihydroxywitha-5,25(27)-dienolide-3-O-β-D-glucopyranoside (1) and (20R,22R,24R)-12α,21,27-trihydroxy-1-oxowitha-2,5,24-trienolide-27-O-β-D-glucopyranoside (2). The cytotoxicity of isolated compounds was evaluated against human lung carcinoma cells (A549) and human colorectal adenocarcinoma cells (DLD-1), respectively. Compound 2 exhibited cytotoxicity against A549 and DLD-1 cell lines, with IC50 values of 7 and 2.0 μM, respectively. However, for compounds 6 and 7, cytotoxicities were higher against DLD-1 cells with IC(50) values of 0.6 and 0.7 μM. Both compounds blocked the cell cycle in the S-phase and induced apoptosis.
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http://dx.doi.org/10.1016/j.phytochem.2011.07.009DOI Listing
November 2011

Synthesis, cytotoxicity, and haemolytic activity of chacotrioside lupane-type neosaponins and their germanicane-type rearrangement products.

Bioorg Med Chem Lett 2009 Apr 23;19(8):2310-4. Epub 2009 Feb 23.

Laboratoire LASEVE, Chaire de Recherche sur les Agents Anticancéreux d'Origine Naturelle, Université du Québec à Chicoutimi, Chicoutimi, Québec, Canada.

The concise synthesis, via a stepwise glycosylation approach, of lupeol, betulin and betulinic acid O-glycosides bearing a chacotriosyl moiety at the C-3 position is described. All neosaponins as well as their rearrangement products of the germanicane-type were evaluated in vitro for their anticancer and haemolytic activities. Although betulinic acid and betulin 3beta-O-chacotriosides were neither cytotoxic nor haemolytic, their rearrangement products allobetulin and 28-oxoallobetulin 3beta-O-chacotriosides (9 and 10) exhibited a cytotoxicity profile up to fourfold superior to betulinic acid against human breast (MCF7) and prostate (PC-3) adenocarcinomas cell lines (IC(50)=10-18 microM). One important result was that only chacotriosides featuring non-polar functions at the C-28 position (6, 9 and 10) exerted a haemolytic activity against red blood cells.
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http://dx.doi.org/10.1016/j.bmcl.2009.02.076DOI Listing
April 2009

Synthesis and cytotoxicity of bidesmosidic betulin and betulinic acid saponins.

J Nat Prod 2009 Jan;72(1):72-81

Laboratoire d'Analyse et de Separation des Essences Vegetales (LASEVE), Departement des Sciences Fondamentales, Universite du Quebec a Chicoutimi, Chicoutimi, Quebec, Canada, G7H 2B1.

The naturally occurring cytotoxic saponin 28-O-beta-d-glucopyranosylbetulinic acid 3beta-O-alpha-l-arabinopyranoside (3) was easily synthesized along with seven bidesmosidic saponins starting from the lupane-type triterpenoids betulin (1) and betulinic acid (2). As highlighted by the preliminary cytotoxicity evaluation against A549, DLD-1, MCF7, and PC-3 human cancer cell lines, the bidesmosidic betulin saponin 22a, bearing alpha-l-rhamnopyranoside moieties at both C-3 and C-28 positions, was determined to be a potent cytotoxic agent (IC(50) 1.8-1.9 microM).
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http://dx.doi.org/10.1021/np800579xDOI Listing
January 2009

Cytotoxic steroidal saponins from the flowers of Allium leucanthum.

Molecules 2008 Nov 26;13(12):2925-34. Epub 2008 Nov 26.

Tbilisi State Medical University, Departement of Pharmacognosy, 33, Vazha Pshavela Ave., Tbilisi, 0177, Georgia.

Allium leucanthum C. Koch is an endemic Caucasian species that grows in Georgia. The flowers are used in traditional medicine. Phytochemical investigation allowed the isolation of seven spirostanol type saponins from the flowers. Their structures were elucidated on the base of NMR and HRESIMS spectrometry data. A new compound, which we have named leucospiroside A (5), has been identified as (25R)-5alpha-spirostane-2alpha,3beta,6beta-triol 3-O-beta-glucopyranosyl-(1-->3)-beta-glucopyranosyl-(1-->2)-[beta-glucopyranosyl-(1-->3)]-beta-glucopyranosyl-(1-->4)-beta-galactopyranoside. The six others were known substances, but are described in this plant for the first time. The crude extract, spirostanol and furostanol fractions, as well as isolated compounds, were evaluated for their in vitro cytotoxic activity. Compounds 1-3 and 5 were found to be the most active, with relatively similar IC50 values ranging from 3.7 to 5.8 microM for a lung cancer cell line (A549) and 5.6 to 8.2 microM for a colon cancer cell line (DLD-1).
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http://dx.doi.org/10.3390/molecules13122925DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6245281PMC
November 2008

Isolation and identification of cytotoxic compounds from the wood of Pinus resinosa.

Phytother Res 2008 Jul;22(7):919-22

Laboratoire LASEVE, Université du Québec à Chicoutimi, Chicoutimi (Québec), Canada.

Methanol extracts of wood from Pinus resinosa were found to be selectively cytotoxic against human lung carcinoma cells, A549 (IC50 41 +/- 6 microg/mL), human colorectal adenocarcinoma cells, DLD-1 (IC50 47 +/- 4 microg/mL) in comparison with healthy cells, WS1 (IC50 130 +/- 11 microg/mL). Five known compounds were isolated and identified by 1H, 13C NMRspectroscopy and HR-ESI-MS mass spectrometry as, pinosylvin monomethyl ether (1), pinosylvin (2), pinosylvin dimethyl ether (3), pinobanksin (4) and (-)-norachelogenin (5). Compound 4 was isolated for the first time in P. resinosa. The cytotoxicity of compounds 1-5 was evaluated against A549, DLD-1 and WS1. Compound 1 exhibited the strongest cytotoxicity against both tumor cell lines and the healthy cell line with an IC50 of 25 +/- 4 microm for A549, 20 +/- 1 microm for DLD-1 and 34 +/- 3 microm for WS1.
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http://dx.doi.org/10.1002/ptr.2416DOI Listing
July 2008

A new labdane diterpene from the flowers of Solidago canadensis.

Chem Pharm Bull (Tokyo) 2008 Jan;56(1):82-4

LASEVE, Département des Sciences Fondamentales, Université du Québec à Chicoutimi, Quebec, Canada.

A new labdane diterpene, 9alpha,16xi-dihydroxy-6-oxo-7,13-labdadien-15,16-olide (solicanolide, 1) and six known compounds identified as quercetin (2), 3-O-caffeoylquinic acid (3, neochlorogenic acid), 5-O-caffeoylquinic acid (4, chlorogenic acid), 4,5-di-O-caffeoylquinic acid (5), 3,5-di-O-caffeoylquinic acid (6) and 3,4-di-O-caffeoylquinic acid (7) were isolated from the flowers of Solidago canadensis. To our knowledge, compound 7 was isolated for the first time in S. canadensis. This work describes the isolation of compounds 1-7 and the structure elucidation of a new compound identified as compound 1. Solicanolide (1) showed cytotoxic activity against A549 (IC(50): 13+/-2 microM), DLD-1 (IC(50): 26+/-2 microM) and WS1 (IC(50): 17+/-1 microM) cell lines.
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http://dx.doi.org/10.1248/cpb.56.82DOI Listing
January 2008

Anticancer diarylheptanoid glycosides from the inner bark of Betula papyrifera.

Phytochemistry 2007 Oct 27;68(20):2531-6. Epub 2007 Jun 27.

Laboratoire d'Analyse et de Séparation des Essences Végétales, Département des Sciences Fondamentales, Université du Québec à Chicoutimi, 555 boul. Université, Chicoutimi, Québec, Canada G7H 2B1.

Phytochemical investigations of the MeOH extract of Betula papyrifera inner bark led to the isolation of ten phenolic compounds of the following types: diarylheptanoid glycosides (1-4), a diarylheptanoid (5), a lignan (6), flavonoids (7-8) and chavicol glycosides (9-10). Among them, the diarylheptanoid glycoside, (S)-1,7-bis-(4-hydroxyphenyl)-heptan-3-one-5-O-alpha-L-arabinofuranosyl-(1-->6)-beta-D-glucopyranoside, papyriferoside A (1), was isolated and its structure was determined on the basis of 1D and 2D NMR, HPLC-MS, as well as high resolution mass spectroscopic data. Platyphylloside (4) exerted the strongest cytotoxic activity of all isolated compounds with IC(50) values ranging from 10.3 to 13.8 microM.
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http://dx.doi.org/10.1016/j.phytochem.2007.05.018DOI Listing
October 2007

Composition and cytotoxic activity of the leaf essential oil of Comptonia peregrina (L.) Coulter.

Phytother Res 2007 Jun;21(6):536-40

Laboratoire d'analyse et de séparation des essences végétales, Département des sciences fondamentales, Université du Québec à Chicoutimi, Chicoutimi, Québec, Canada, G7H 2B1.

Comptonia peregrina (L.) Coulter, a native plant from Canada used in traditional medicine against cancer, was extracted by hydrodistillation. Two fractions were collected, one over 0-30 min and one over 30-60 min, to assess the influence of time of hydrodistillation on the composition of essential oil. The chemical composition of these two extracts was determined by GC and GC-MS analyses. Fifty five components were identified: beta-caryophyllene (23.69% and 15.16%) and alpha-humulene (9.67% and 7.43%) were the major components in the 0-30 min and 30-60 min fractions, respectively, while beta-myrcene was detected in a higher amount in the 0-30 min fraction (12.58%) than in the 30-60 min fraction (0.15%). The cytotoxic activities of these fractions were assessed against human lung carcinoma cell line A-549 and human colon adenocarcinoma cell line DLD-1. Only the 30-60 min fraction was found to be active against both tumor cell lines, with GI(50) values of 66 +/- 12 microg/mL for A-549 and of 46 +/- 7 microg/mL for DLD-1. Two sesquiterpenes present in the oil, alpha-humulene and (E)-nerolidol, have been found to be cytotoxic against both tumor cell lines.
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http://dx.doi.org/10.1002/ptr.2095DOI Listing
June 2007

Antioxidant, anti-inflammatory and anticancer activities of methanolic extracts from Ledum groenlandicum Retzius.

J Ethnopharmacol 2007 Apr 26;111(1):22-8. Epub 2006 Oct 26.

Laboratoire LASEVE, Université du Québec à Chicoutimi, 555, Boulevard de l'Université, Chicoutimi, Québec, Canada.

Labrador tea (Ledum groenlandicum Retzius) is an ericaceae widely distributed in North America. The leaves and twigs were used in Native American traditional medicine to treat several inflammatory pathologies such as asthma, rheumatisms and burns. Reactive oxygen species as well as reactive nitrogen species such as nitric oxide (NO) contribute significantly to these pathologies. In this study, the antioxidant, anti-inflammatory and anticancer activities of crude methanol extracts of leaves and twigs from Ledum groenlandicum were investigated. Both extracts showed a strong antioxidant activity using the ORAC method and a cell based-assay. Moreover, the twig and leaf extracts showed significant anti-inflammatory activity, inhibiting NO release, respectively, by 28 and 17% at 25 microg/ml in LPS-stimulated RAW 264.7 macrophages. In comparison, N(G)-nitro-L-arginine methyl ester (L-NAME), a nitric oxide synthase inhibitor, reduced NO release by 24% at 25 microg/ml. The twig extract was also found to be active against DLD-1 colon carcinoma and A-549 lung carcinoma cells, with IC(50) values of 43+/-1 and 65+/-8 microg/ml, respectively. The bioguided study of the twig extract resulted in the isolation and identification of ursolic acid, a known triterpene. Ursolic acid was active against DLD-1 (IC(50): 9.3+/-0.3 microM) and A-549 (IC(50): 8.9+/-0.2 microM), suggesting it is, in part, responsible of the anticancer activity of the twig extract.
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http://dx.doi.org/10.1016/j.jep.2006.10.021DOI Listing
April 2007
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