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| Format: | Artículo científico |
| Language: | en |
| Published: |
Academia Brasileira de Ciências
2005
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| Online Access: | https://www.redalyc.org/articulo.oa?id=32777204 |
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Table of Contents:
- Golden mussel Limnoperna fortunei (Bivalvia:Mytilidae) distribution in the main hydrographical basins of Uruguay: up date and predictions Ernesto Brugnoli Juan Clemente Lucía Boccardi Ana Borthagaray Fabrizio Scarabino Multidisciplinaria (Ciencias Naturales y Exactas) GC NMR partiallyO MSstandards OHreactivity ArabinoseandgalactoseweretreatedwithMeOHcontainingtracesofH2SO4orHClat25◦Ctogivemixturesoftheirmethylalpha-andbeta-furanosides,asshownby1Dand2Dnuclearmagneticresonance(NMR).OxidationoftheMealpha,beta-ArafmixturewithNaIO4preferentiallyoxidisedthebeta-isomer,togivepureMealpha-Araf.EachproductwasprogressivelyO-methylatedusingthePurdiereagent(MeI/Ag2O)at25◦Candresultingmixturesofpartiallymethylatedglycosides(PMGs)wererapidlyassayedbythinlayerchromatography(TLC)firsttofavourhigheryieldsofmono-O-methylderivativesandlaterforproductswithhigherdegreesofmethylation.TheproductswereconvertedtocomplexmixturesofpartiallyO-methylatedalditolacetatederivatives(PMAAs)bysuccessivehydrolysis,reductionwithNaBD4,andacetylation.Thesecanbeusedasgaschromatography-massspectrometry(GC-MS)standardsinmethylationanalysisofcom-plexcarbohydratescontainingarabinofuranosylandgalactofuranosylunits.OfparticularinterestweretheretentiontimesandelectronimpactMSofthedifficulttopreparealditolacetatesof5,6-Me2Gal,2,5-Me2Gal,2,5,6-Me3Gal,3,5,6-Me3Gal,5-MeAra,2,5-Me2Ara,and3,5-Me2Ara.TherelativereactivitiesofhydroxylgroupsformixturesofMealpha-andMebeta-GalfwereHO-2>HO-3>HO-6>HO-5,thatofMealpha-andMebeta-ArafHO-2>HO-3>HO-5,andthatofMealpha-ArafHO-2>HO-3≥HO-5. 2005 artículo científico 0001-3765 https://www.redalyc.org/articulo.oa?id=32777204 en http://www.redalyc.org/revista.oa?id=327 Anais da Academia Brasileira de Ciências application/pdf Academia Brasileira de Ciências Anais da Academia Brasileira de Ciências (Brasil) Num.2 Vol.77