Stress metabolites

Key Words Carotenoid chitosan methyl jasmonate phenolic compound salinity secondary metabolites stress response terpenoid. 

Alsaker KV, Paredes C, Papoutsakis ET. (2010). Metabolite stress and tolerance in the production of biofuels and chemicals gene-expression-based systems analysis of butanol, butyrate, and acetate stresses in the anaerobe Clostridium acetobutylicum. Biotechnol Bioeng, 105, 1131-1147. 

Nifurtimox, a nitrofuran, is a prodrug that is reduced to unstable nitroanion radicals, which react to produce highly toxic oxygen metabolites, such as superoxide and peroxide. Oxidative stress subsequently kills the parasite, which seems to lack effective enzymatic pathways to detoxify oxygen metabolites. 

Very large Serine/Threonine kinases and the molecular Target of Rapamycin, a naturally occurring secondary metabolite, TOR proteins function within multiprotein complexes to couple cell growth and stress responses to environmental and developmental cues. 

Sharkey, T.D. Badger, M.R. (1982). Effects of water stress on photosynthetic electron transport, photophosphorylation and metabolite levels of Xanthium strumarium mesophyll cells. Planta, 156, 199-206. 

Smirnoff, N. Stewart, G.R. (1985). Stress metabolites and their role in coastal plants. Vegetatio, 62, 273-8. 

Another interesting furan is ipomeamarone (39), a stress metabolite produced by sweet potatoes when they are attacked by fungi. 

The effect of a particular cultivation environment on a system can be evaluated in terms of biomass (fresh/dry weight, cell number), secondary metabolite production [51,75,89,102,103,106,107] or substrate consumption (e.g. carbon source [57] or oxygen [53,108]). Using the Evan s Blue method to identify non-viable cells. Ho et al. [108] used viable cell density measurements to determine variations in specific growth rate attributable to hydrodynamic stress. 

Another study showed that a mixture of oxidative metabolites of P-carotene, but not P-carotene, was able to increase the binding of benzo[a]pyrene to DNA. Other mixtures of P-carotene cleavage products have been shown to induce oxidative stress in vitro,exert cytotoxic and genotoxic effects, and inhibit gap junction intercellular communications. It has been suggested that these detrimental effects could possibly occur in vivo following the intake of high doses of carotenoids. 

Although it is widely accepted that ischaemia/ reperfusion-induced oxidant stress is associated with a reduction of Na/K ATPase activity, it is difficult to determine which features of this process are responsible for this effect. A classical approach to this type of problem has been to determine the effect of the application of selected metabolites or agents on the activity of the enzyme of interest, an approach that has been exploited for the sarcolemmal Na/K ATPase and glutathione (Haddock et al., 1990). The application of GSH (O.l-l.OmM) induces a concentration-dependent increase in the activity of a bovine isolated ventricular Na/K ATPase preparation (determined by the ouabain-sensitive hydrolysis of ATP to release inorganic phosphate). In the presence of 1 mM GSH there was a 38% stimulation of activity compared to untreated control... 

We have already stressed the potential importance of lipid-rich membranes in the skin as potential targets for ROS-induced damage and ageing of human skin is morphologically identical to changes found by peroxidative processes (Serri et al., 1977). The involvement of AA metabolites in skin disease, and in particular psoriasis, has been the subject of much recent interest. Studies have included topical and intradermal administrations of AA metabolites, and assay of such products in clinical specimens. Results show that concentration of AA, 12-hydroxy-eicosatetraenoic acid (12-HETE), PG and leu-kotrienes are increased in psoriatic lesions (Hammarstrom etal., 1975 Camp etal., 1983 Brain etal., 1984 Duell et al., 1988) and also that full-thickness epidermis from normal and diseased skin has the enzymatic capacity to convert AA to some of the same metabolites (Hammarstrom etal., 1975, 1979 Camp etal., 1983 Brain etal., 1984 Ziboh et al., 1984 DueU et al., 1988). The biological effect of both 12-HETE and leukotrienes was confirmed by both topical application and intradermal injection, which caused epidermal inflammation and... 

Similarly, abnormalities in the mitochondrial machinery and resulting oxidative stress may also intervene in Parkinson s disease (PD) [31, 32]. The decreased activity of mitochondrial complex I in PD patients [33], and the preferential toxicity of the complex I inhibitor rotenone [34] and MPP+ (the active metabolite of MPTP)... 

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