Variable stereochemistry in highly branched isoprenoids from diatoms.
Chirality
; 13(8): 415-9, 2001 Aug.
Article
en En
| MEDLINE
| ID: mdl-11466760
ABSTRACT
C(25) highly branched isoprenoid (HBI) alkenes are ubiquitous lipids found in geochemical samples around the globe. The origins of these widespread geochemicals are believed to be restricted to a limited number of diatoms, including Haslea ostrearia (and related species), Rhizosolenia setigera, and Pleurosigma intermedium. The unsaturation of the HBI alkenes ranges from 2-6 in different species and cultures. The number of stereogenic centres is usually limited to two in the HBI alkenes due to double bond positions. The relative and/or absolute configurations for these have been determined for a range of HBI alkenes produced from different diatoms cultured under a number of growth conditions. These determinations have involved a combined spectroscopic and chromatographic analysis using NMR spectroscopy and chiral gas chromatography, respectively. HBIs isolated from Haslea spp. belong to a specific structural type which exhibit configurational diastereoisomerism, while those isolated from P. intermedium and R. setigera represent a different structural type and usually exist as mixtures of geometric isomers only. HBIs are reported from a new species of diatom whose stereochemical properties lie between those found for Haslea spp. and P. intermedium.
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Base de datos:
MEDLINE
Asunto principal:
Terpenos
/
Diatomeas
/
Alquenos
Idioma:
En
Revista:
Chirality
Asunto de la revista:
BIOLOGIA MOLECULAR
/
QUIMICA
Año:
2001
Tipo del documento:
Article