Characterizing the Biochemical Role of an Unusual Fatty Acyl-AMP Ligase from a Hybrid PKS-NRPS Pathway in Nematodes.

PKAL-1 is a fatty acyl-AMP ligase that plays an essential role in the biosynthesis of the nemamides, hybrid polyketide-nonribosomal peptides from nematodes that promote recovery from starvation-induced larval arrest. This enzyme traffics biosynthetic intermediates between two enzymatic assembly lines: the hybrid polyketide synthase-nonribosomal peptide synthetase PKS-1 and the nonribosomal peptide synthetase NRPS-1. Specifically, a mutant worm strain does not produce the nemamides but accumulates a β-amino-containing polyketide, named nematide A, which is made by PKS-1 and is potentially loaded by PKAL-1 onto NRPS-1.

Comparative Metabolomics Identifies the Roles of Acyl-CoA Oxidases in the Biosynthesis of Ascarosides and a Complex Family of Secreted -Acylethanolamines.

The nematode produces a large family of ascaroside pheromones, which it uses in chemical communication to coordinate the development and behavior of the population. The acyl-CoA oxidase (ACOX) enzymes, which catalyze the first rate-limiting step in peroxisomal β-oxidation, act as gatekeepers for the biosynthesis of ascarosides with specific side-chain lengths. By performing unbiased comparative metabolomics on , , , , and mutant worms and double mutant worms, we provide a comprehensive view of the different roles of these enzymes in ascaroside biosynthesis and implicate them in a number of additional biosynthetic pathways.

Discovery of a parallel family of euglenatide analogs in Euglena gracilis.

The euglenatides are a family of hybrid polyketide-nonribosomal peptides produced by the unicellular algae Euglena gracilis. These compounds have antiproliferative activity against fungal pathogens and mammalian cancer cell lines. Analysis of E.

An acyl-CoA thioesterase is essential for the biosynthesis of a key dauer pheromone in C. elegans.

Methyl ketone (MK)-ascarosides represent essential components of several pheromones in Caenorhabditis elegans, including the dauer pheromone, which triggers the stress-resistant dauer larval stage, and the male-attracting sex pheromone. Here, we identify an acyl-CoA thioesterase, ACOT-15, that is required for the biosynthesis of MK-ascarosides. We propose a model in which ACOT-15 hydrolyzes the β-keto acyl-CoA side chain of an ascaroside intermediate during β-oxidation, leading to decarboxylation and formation of the MK.

Optimization of the Sulfo-Phospho-Vanillin Assay for Total Lipid Normalization in Untargeted Quantitative Lipidomic LC-MS/MS Applications.

Liquid chromatography (LC)-mass spectrometry (MS)/MS lipidomic normalization is generally performed by equalizing pre-extraction sample materials or via DNA or protein pre-quantitation methods, which have known measurement inaccuracies. We propose the use of the sulfo-phospho-vanillin assay (SPVA), a total lipid colorimetric analysis, as a pre-quantitation method to normalize lipids in lipidomic LC-MS/MS applications. The assay has been applied to a 300 μL well volume in a 96-well plate and tested using Avanti total lipid standards of porcine brain and .

Palladium-catalyzed regioselective C-2 arylation of 7-azaindoles, indoles, and pyrroles with arenes.

A palladium-catalyzed regioselective C-2 arylation of 7-azaindoles, indoles, and pyrroles with arenes has been developed. This study unveils that a critical substrate dependent acid concentration is essential for achieving exclusive C-2 selectivity as well as mono-arylation in pyrroles. Incongruent to the literature, the protocol uses a reduced volume (at least 5 times) of arenes for workable access to C-2 arylated heterocycles.

Access to biaryl sulfonamides by palladium-catalyzed intramolecular oxidative coupling and subsequent nucleophilic ring opening of heterobiaryl sultams with amines.

The installation of sulfonamide pharmacophores on heterobiaryls has successfully been executed by a previously unknown palladium-catalyzed intramolecular oxidative coupling in N-arylsulfonyl heterocycles followed by novel ring opening of heterobiaryl sultams with amine nucleophiles. The protocol has a wide scope of substrates warranting broad applications in the synthesis of heterobiaryls containing an o-sulfonyl or carboxyl functional group.