Low-molecular-weight metabolite systems chemistry

Abstract

Low-molecular-weight metabolites (LMWMs) comprise primary or central and a plethora of intermediary or secondary metabolites, all of which are characterized by a molecular weight below 900 Dalton. The latter are especially prominent in sessile higher organisms, such as plants, corals, sponges and fungi, but are produced by all types of microbial organisms too. Common to all of these carbon molecules are oxygen, nitrogen and, to a lesser extent, sulfur, as heteroatoms. The latter can contribute as electron donators or acceptors to cellular redox chemistry and define the potential of the molecule to enter charge-transfer complexes. Furthermore, they allow LMWMs to serve as organic ligands in coordination complexes with various inorganic metals as central atoms. Especially the transition metals Fe, Cu, and Mn can catalyze one electron reduction of molecular oxygen, which results in formation of free radical species and reactive follow-up reaction products. As antioxidants LMWMs can scavenge free radicals. Depending on the chemical environment, the same LMWMs can act as pro-oxidants by reducing molecular oxygen. The cellular regulation of redox homeostasis, a balance between oxidation and reduction, is still far from being understood. Charge-transfer and coordination complex formation with metals shapes LMWMs into gel-like matrices in the cytosol. The quasi-polymer structure is lost usually during the isolation procedure. In the gel state, LMWMs possess semiconductor properties. Also proteins and membranes are semiconductors. Together they can represent biotransistor components that can be part of a chemoelectrical signaling system that coordinates systems chemistry by initiating cell differentiation or tissue homeostasis, the activated and the resting cell state, when it is required. This concept is not new and dates back to Albert Szent-Györgyi.

Enzyme-linked immunosorbent assay for the quantitative/qualitative analysis of plant secondary metabolites

“…Most of the useful plant secondary metabolites are low molecular weight compounds (i.e., hapten) with immense structural diversity, which are generally classified on the basis of their biosynthesis pathway [ 30 , 31 ]. Hence, ELISA used for their analysis is the competitive type (competitive ELISA or icELISA) using MAb or PAb.…”

Metabolomic insights into the intricate gut microbial–host interaction in the development of obesity and type 2 diabetes

“…Metabolomics has recently attracted attention as the most suitable - omics technology for investigating complex, polygenic and multifactorial diseases with a strong metabolic etiology, such as obesity and T2D as well as the crosstalk of distinct predisposing factors in disease development and progression ( Faber et al, 2007 ; Llorach et al, 2012 ; Du et al, 2013 ; Kurland et al, 2013 ). Aimed at the comprehensive analysis of the low- molecular- weight compounds contained in a biological system –by definition, metabolites comprise a plethora of primary or secondary derivatives of the intermediate metabolism (molecular weight below 900 and 2000 Dalton, depending on sources; Beckonert et al, 2010 ; Psychogios et al, 2011 ; Hadacek, 2015 ) metabolomics represents a powerful tool for exploring the crosstalk between the microbial and host metabolism in a more exhaustive fashion.…”

Anti-Inflammatory Potential of Cow, Donkey and Goat Milk Extracellular Vesicles as Revealed by Metabolomic Profile

“…While the majority of previous EVs studies deal with protein and nucleic acid cargos, the role of other components such as metabolites has been overlooked until recently [ 29 , 37 , 38 , 39 , 40 , 41 ]. Metabolites represent a bio-functional category, also composed of low-molecular-weight (<1 kDa) components, that generally refer to small end product biomolecules or intermediates involved in metabolic processes such as alcohols, amides, amino acids, carboxylic acids and sugars [ 42 ].…”