Position and configuration of double bonds of lipid A-associated monounsaturated fatty acids of Proteobacferia and Rhodobacter capsulatus 37b4

Abstract

The double bond of dodecenoic acid in the endotoxin-antagonistically acting lipid A of Rhodobacter capsulatus, strains 37b4 and St Louis, was found to have cis-configuration. The position of the double bond was ω7. The mono-unsaturated fatty acids of lipid A from a number of additionally investigated strains of various species of the α-, β-, and γ-subgroups of Proteobacteria (Agrobacterium spp., Azospirillum spp., Rhizobium meliloti, Rhodobacter sphaeroides, Rhodomicrobium vannielii, Rhodopseudomonas blastica, Rhodospirillum salinarum, Sphaerotilus natans, Thiobacillus spp. and Yersinia enterocolitica) have also cis -configuration with the double bond in the ω7-position (one exception), suggesting the anaerobic pathway of biosynthesis to be common for most of them.

Structure of a novel lipid A obtained from the lipopolysaccharide of Caulobacter crescentus

“…Although some bacterial species (such as Campylobacter and Flavobacterium) are found to contain trans-double bonds, all unsaturated fatty acids of the Proteobacteria lipid A contain ω7-cis-double bonds. 33,38 The structure of the Caulobacter lipid A can now be completely described. Collectively, the major (determined by NMR analysis) are present at the 3-and 2-positions of the reducing-end subunit DAG A, respectively.…”

Cyanobacterial toxins: Modes of actions, fate in aquatic and soil ecosystems, phytotoxicity and bioaccumulation in agricultural crops

“…Today, only two congeners of cylindrospermopsin have been identified: 7-epicylindrospermopsin and deoxycylindrospermopsin. The freshwater cyanobac-erial irritant toxins such as lipopolysaccharides (LPS), or endotoxins as they are commonly called, are major components of the cell wall in most Gram-negative bacteria including cyanobacteria (Jann and Jann, 1984;Mayer and Weckesser, 1984;Kaya, 1996;Stewart et al, 2006).…”

Outer membrane vesicles of Dinoroseobacter shibae transport a volatile aldehyde

“…This indicates that 1 indeed occurs as the sole free acid in the OMVs, in contrast to the other acids reported by Wang et al that obviously are present in bound form, presumably mostly in the membrane phospholipids. Acid 1 has already been described from Rhodobacter capsulatus (Mayer et al, 1996), Escherichia coli (Feng and Cronan, 2009) and other bacteria (Moss and Daneshvar, 1992). The volatile aldehyde 8 has not been reported from bacteria so far, but is known as a sex pheromone of moths, e.g., Gastropacha quercifolia (Bestmann et al, 1993) and Dendrolimus punctatus (Zhao et al, 2004) and in the anal gland of the European rabbit (Goodrich et al, 1978).…”