Jacob J. auteur aut IRD Disnar J.R. auteur aut IRD Boussafir M. auteur aut IRD Albuquerque A.L.S. auteur aut IRD Sifeddine Abdelfettah auteur aut IRD Turcq Bruno auteur aut IRD text journalArticle eng text/pdf born digital access The lipid extracts of sediments collected from the Quaternary filling of a tropical lacustrine series (Lagoa do Caco, Brazil) were investigated using gas chromatography-mass spectrometry (GC-MS). Various pentacyclic triterpene 3-methyl ethers (PTMEs) were present in the neutral fraction. Comparison of retention times and mass spectra with available standards allowed us to confirm the presence of olean-12-en-3beta-ol ME (beta-amyrin ME), olean-18-en-3beta-ol ME (miliacin), taraxer- 14-en-3beta-ol ME (crusgallin), fern-9(l I)-en-3beta-ol ME (arundoin) and arbor-9(11)-en-3beta-ol ME (cylindrin). The following other compounds could also be tentatively identified from their GC-MS characteristics: urs-12-en-3beta-ol ME, bauer-7-en-3beta-ol ME and fern-8-en-3beta-ol ME. Other compounds such as possible 3alpha isomers of the PTMEs as well as di- or tri-unsaturated counterparts might be PTME diagenetic derivatives. According to previous chemotaxonomic studies, all these compounds most probably originate from Gramineae that used to colonize the savanna of Northern Brazil at the time of deposition. (C) 2004 Elsevier Ltd. All rights reserved. specialized 064 36 (3) 449-461 2005 0146-6380 https://www.documentation.ird.fr/hor/fdi:010042255 10.1016/j.orggeochem.2004.09.005 0146-6380 [F B010042255] https://www.documentation.ird.fr/hor/fdi:010042255 https://www.documentation.ird.fr/intranet/publi/depot/2016-08-11/010042255.pdf Accès réservé (Intranet de l'IRD) IRD - Base Horizon / Pleins textes 2006-03-29 2017-08-23 fdi:010042255 fre