The biosynthesis of the plasmalogen forms of phosphatidylethanolamine (plasmenylethanolamine) and phosphatidylglycerol (plasmenylglycerol) and of the glycerol acetal of plasmenylethanolamine has been studied in cultures of Clostridium butyricum IFO 3852. When growing cells were pulsed with [32P]orthophosphate, there was a lag of 5 to 7 min between the rapid incorporation of label into the acylp...

Cytochrome P450 (P450) assays use probe substrates to interrogate the influence of new chemical entities toward P450 enzymes. We report the synthesis and study of a family of bioluminogenic luciferin acetal substrates that are oxidized by P450 enzymes to form luciferase substrates. The luciferin acetals were screened against a panel of purified P450 enzymes. In particular, one proluciferin acet...

Bacterial biofilms are surface associated bacterial communities of sessile cells encased in a matrix of polysaccharides, extracellular DNA and proteins. Such biofilms are of significant concern in nosocomial infections, where it is attributed to over $1 billion in increased hospital costs per annum in the US alone. Unlike cells in the planktonic state, bacterial biofilms do not exert their anti...

More than 20,000 people suffer annually from ciguatera seafood poisoning in subtropical and tropical regions. The extremely low content of the causative neurotoxins, designated as ciguatoxins, in fish has hampered isolation, detailed biological studies, and preparation of anti-ciguatoxin antibodies for detecting these toxins. Furthermore, the large (3 nm in length) and complex molecular structu...

Acetalization of 2-methylbenzaldehyde is a type reaction that occur by reacting with methanol. Meanwhile, the catalyst used in an acid catalyst. This research was conducted to determine pathway intermediate mechanism most likely produce acetal product. The software this HyperChem 8.0, 6-31G* basis sets, ab initio method. Before being calculated, molecular structure drawn 2-dimensional view. Aft...

Two cobalt-carbonyl oxo processes were developed to prepare useful products in high yield from fatty derivatives. In one process, hydroformylation in the presence of MeOH at 120 C gives dimethyl acetal esters from either methyl oleate or oleic acid. In the other, a two-step process, hydroformylation (120 C) followed by hydrogenation (180 C) gives better yields of hydroxY methyl esters from both...

The crystal structure of the title compound, C(13)H(14)O(5), establishes (i) the (S) - rather than (R) - configuration at the acetal carbon and (ii) that both the acetal and the lactone form five- rather than six-membered rings; the absolute configuration is determined by the use of 2-C-methyl-d-ribono-1,4-lactone as the starting material. The compound consists of hydrogen-bonded chains of mol-...

O-polysaccharides were isolated from the lipopolysaccharides of Escherichia coli O40 and Shigella dysenteriae type 9 and studied by chemical analyses along with (1)H and (13)C NMR spectroscopy. The following new structure of the O-polysaccharide of E. coli O40 was established: -->2)-beta-D-Galp-(1-->4)-beta-D-Manp-(1-->4)-alpha-D-Galp-(1-->3)-beta-D-GlcpNAc-(1--> TheO-polysaccharide structure o...

Acetaldehyde diethyl acetal (herein called acetal) is an important pollutant of anhydrous ethanol. Isobaric vapor–liquid equilibrium (VLE) ethanol–acetal binary system was measured using a vapor condensate and liquid circulation VLE still. The experimental data were correlated with Wilson, nonrandom two-liquid (NRTL), universal quasichemical (UNIQUAC) activity coefficient models, which found su...

A synthetic strategy for the modeling construction of the highly bridged azatetracyclic ABEF ring system of numerous lycoctonine-type C19-diterpenoid alkaloids bearing a characteristic oxygenated quaternary center at C-7 has been successfully developed. The tetracyclic core was constructed rapidly from a readily prepared 6,7-bicyclic AB ring precursor through a 13-step sequence via an advanced ...