Single-cell level measurements are necessary to characterize the intrinsic biological variability in a population of cells. In this study, we demonstrate that, with the microarrays for mass spectrometry platform, we are able to observe this variability. We monitor environmentally (2-deoxy-d-glucose) and genetically (ΔPFK2) perturbed Saccharomyces cerevisiae cells at the single-cell, few-cell, and population levels. Correlation plots between metabolites from the glycolytic pathway, as well as with the observed ATP/ADP ratio as a measure of cellular energy charge, give biological insight that is not accessible from population-level metabolomic data.
Alfredo J. Ibáñeza,1,Stephan R. Fagerera,1,Anna Mareike Schmidtb,Pawel L. Urbanc,Konstantins Jefimovsd,Philipp Geigera,Reinhard Dechante,Matthias Heinemannf, andRenato Zenobia,2
The addition of a DNA methyltransferase inhibitor, 5-azacytidine, to Aspergillus sydowii fungus culture broth changed its secondary metabolites profile. Analysis of the culture broth extract led to the isolation of three new bisabolane-type sesquiterpenoids: (7S)-(+)-7-O-methylsydonol (1), (7S,11S)-(+)-12-hydroxysydonic acid (2) and 7-deoxy-7,14-didehydrosydonol (3), along with eight known compounds. The isolated compounds were evaluated for their anti-diabetic and anti-inflammatory activities. Among the isolates, (S)-(+)-sydonol (4) did not only potentiate insulin-stimulated glucose consumption but also prevented lipid accumulation in 3T3-L1 adipocytes. Additionally, (S)-(+)-sydonol (4) exhibited significant anti-inflammatory activity through inhibiting superoxide anion generation and elastase release by fMLP/CB-induced human neutrophils. This is the first report on isolating a secondary metabolite with anti-diabetic and anti-inflammatory activities from microorganisms.
For almost 200 years, the synthesis of natural products has been practiced. In this time span, not only the target structures have become increasingly more complex (see two examples from the 1970s), the objectives of natural product synthesis have also changed. Likewise, the standards and criteria for the conduction of natural product synthesis have changed. It is these changes that form the subject of this essay.
Dr. Jeroen Gillard, Johannes Frenkel, Valerie Devos, Prof. Dr. Koen Sabbe, Carsten Paul, Dr. Martin Rempt, Prof. Dr. Dirk Inzé, Prof. Dr. Georg Pohnert, Prof. Dr. Marnik Vuylsteke, Prof. Dr. Wim Vyverman Angewandte Chemie International Edition DOI: 10.1002/anie.201208175
Synthetic chemistry has long been used to prepare useful compounds — especially those that are hard to obtain from natural sources. But synthetic biology is coming of age as an alternative strategy. A biologist and two chemists debate the merits of their fields' synthetic prowess.
Jay D. Keasling, Abraham Mendoza & Phil S. Baran Nature 492, 188–189 (13 December 2012) doi:10.1038/492188a
The post-PKS modification steps of FK506 biosynthesis include C9-oxidation and 31-O-methylation, but the sequence of these reactions and the exact route have remained unclear. This study details the post-PKS modification pathways in FK506 biosynthesis through the identification of all intermediates and in vitro enzymatic reactions of the cytochrome P450 hydroxylase FkbD and the methyltransferase FkbM. These results complete our understanding of post-PKS modification steps to FK506 showing the substrate flexibility of two enzymes involved and the existence of two parallel biosynthetic routes to FK506.
Yeon Hee Ban†, Pramod B. Shinde†§, Jae-yeon Hwang†, Myoung-Chong Song†, Dong Hwan Kim, Si-Kyu Lim, Jae Kyung Sohng, and Yeo Joon Yoon
Mollolide A (1), a diterpenoid featuring a new 1,10:2,3-disecograyanane skeleton, was isolated from the roots of Rhododendron molle. Its structure was elucidated through extensive MS, IR, and NMR spectroscopy analyses. The absolute configuration was determined by single-crystal X-ray diffraction of its p-bromobenzoate derivative (1b). Compound 1 exhibits a significant analgesic effect at a dose of 20 mg/kg and antiviral activity against the Coxsackie B3 virus with an IC50 value of 27.7 μM.
Take a detour: An alternative pathway to synthesize isovaleryl coenzyme A (CoA) has recently been suggested in myxobacteria, which is highly active when leucine is limited. Each enzymatic step of this unprecedented route has now been characterized and a novel 3-methylglutaconyl CoA decarboxylase identified that has apparently evolved from CoA transferases.
Dr. Yanyan Li, Eva Luxenburger, Prof. Dr. Rolf Müller