Long-chain alkenones and related compounds in the benthic haptophyte Chrysotila lamellosa Anand HAP 17 Jean-Franc¸ois Rontani a, *, Be´atriz Beker b , John K. Volkman c a Laboratoire d’Oce ´anographie et de Bioge ´ochimie (UMR CNRS 6535), Centre d’Oce ´anologie de Marseille (OSU), Campus de Luminy, case 901, F-13288 Marseille, France b Centre d’Oce ´anologie de Marseille (OSU), Station marine d’Endoume, F-13007 Marseille, France c CSIRO Marine Research, GPO Box 1538, Hobart, Tasmania 7001, Australia Received 6 June 2003; received in revised form 12 September 2003; accepted 23 September 2003 Abstract The neutral lipid compositions of the coastal haptophyte Chrysotila lamellosa HAP 17 grown in batch culture at 10 and 20  C have been determined. A comparison was also made between the lipid compositions of cells harvested in early and late stationary phase. This species contains a suite of very long-chain C 37 –C 40 alkenones and alkenoates as found in a few microalgae from the Haptophyta. The distributions of these compounds show some differences to earlier reports of different strains of this alga, which are only in part attributable to culture conditions. A suite of long-chain alkenols, the reduced form of the alkenones, was char- acterized for the first time. The abundance of these compounds was only 1.5% of that of the corresponding alkenones, and the relative proportion of C 37 –C 38 constituents depended on growth temperature. These data show that haptophyte algae are a possible source of the alkenols found in some marine sediments, but the small amounts found suggest that other sources such as bacterial reduction of alkenones are more likely in highly reducing sediments. A mixture of C 29 –C 33 n-alkenes, dominated by the C 31:1 monoene, was found in marked contrast to previous analyses of other strains which reported only the presence of a C 31:2 diene. The sterol distribution included the common haptophyte sterol 24a-methylcholesta-5,22E-dien-3b-ol (epi-brassicasterol) as well as significant amounts of  5 - and  5,22 -C 29 sterols. # 2003 Elsevier Ltd. All rights reserved. Keywords: Chrysotila lamellosa; Haptophyte; Microalga; Lipids; Alkenones; Alkenols; Sterols; Long-chain 1. Introduction Alkenones are typically amongst the most abundant extractable lipids in Quaternary marine sediments (Bras- sell, 1993), and the relative abundances of the C 37 com- ponents with different degrees of unsaturation (U k 37 , U k 0 37 ) can be used as a proxy for paleo-sea surface tem- perature (Brassell et al., 1986; Prahl and Wakeham, 1987). Alkenones comprise an unusual class of long- chain unsaturated methyl and ethyl ketones that are synthesized by a limited number of microalgae from the Haptophyta (Volkman et al., 1980a; 1995; Marlowe et al., 1984a; Conte et al., 1994; 1995). Until now they were reported exclusively from the oceanic haptophytes Emiliania huxleyi and Gephyrocapsa oceanica (family Noelaerhabdaceae) and coastal species of Chrysotila and Isochrysis (family Isochrysidaceae) (Marlowe et al., 1984a, 1990; Volkman, 2000). Alkenones possess several unusual characteristics for biolipids, including their very long chain-length (i.e. C 35 –C 40 ) and the spacing (C 7 ) and configuration (E) of their positions of unsaturation (Marlowe et al., 1990). Haptophytes also contain significant abundances of methyl and ethyl alkenoates and alkenes exhibiting simi- lar chemical features (de Leeuw et al., 1980; Volkman et al., 1980b; Marlowe et al., 1984a), although the alkenes also contain C 31 –C 33 components having double bonds with Z geometry (Rieley et al., 1998). Recently, trace amounts of alkenols (the reduced forms of alkenones) were also detected in E. huxleyi, G. oceanica and Isochrysis galbana (Rontani et al., 2001). During the lat- ter study, relatively high amounts of these long-chain 0031-9422/$ - see front matter # 2003 Elsevier Ltd. All rights reserved. doi:10.1016/j.phytochem.2003.09.021 Phytochemistry 65 (2004) 117–126 www.elsevier.com/locate/phytochem * Corresponding author. Tel.: +33-4-91-82-96-23; fax: +33-4-91- 82-65-48. E-mail address: rontani@com.univ-mrs.fr (J.-F. Rontani).