Identification of a C-25 highly branched isoprenoid triene in the freshwater diatom Navicula sclesvicensis

The first example of a freshwater diatom species that biosynthesises the wi despread organic geochemicals known as highly branched isoprenoids (HBIs) i s identified. As a result, diatoms known to produce HBIs now include benthi c, planktonic, marine and freshwater species. Laboratory cultures of a numb er of freshwater diatoms isolated from Swanpool, UK and Paimpont, France we re examined for highly branched isoprenoid (HBI) alkenes. A C-25 HBI triene was identified in Navicula sclesvicensis, and characterised using GC-MS, b y comparison with an authentic standard. (C) 2001 Elsevier Science Ltd. All rights reserved.