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Monascus pigments (MPs) have been used as natural food pigments for many years. There is a high demand for Monascus red pigments (MRPs) to enhance color and for antibacterial and cancer prevention therapies in food and medicine. Most MRPs are not water soluble, and the yield of water‐soluble MRPs is naturally low. On the other hand, water‐soluble MRP is more cost effective for application in industrial mass production. Therefore, it is important to improve the yield of water‐soluble MRPs. Environmental factors have a significant influence on the synthesis of water‐soluble MRPs, which is crucial for the development of industrial production of water‐soluble MRPs. This review introduces the biosynthetic pathways of water‐soluble MRPs and summarizes the effects of environmental factors on the yield of water‐soluble MRPs. Acetyl coenzyme A (acetyl‐CoA) is a precursor for MPs synthesis. Carbon and nitrogen sources and the carbon/nitrogen ratio can impact MP production by regulating the metabolic pathway of acetyl‐CoA. Optimization of fermentation conditions to change the morphology of Monascus can stimulate the synthesis of MPs. The appropriate choice of nitrogen sources and pH values can promote the synthesis of MRPs from MPs. Additives such as metal ions and non‐ionic surfactants can affect the fluidity of Monascus cell membrane and promote the transformation of MRPs into water‐soluble MRPs. This review will lay the foundation for the industrial production of water‐soluble MRPs. © 2024 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Vitis vinifera c.v. Muscat de Frontignan (grape) contains various high valuable bioactive phenolic compounds with pharmaceutical properties and industrial interest which are not fully exploited. The focus of this investigation consists in testing the effects of various biological elicitors on a non-morphogenic callus suspension culture of V. vinifera. The investigated elicitors: Indanoyl-isoleucine (IN), N-linolenoyl-L-glutamine (LG), insect saliva (IS) and malonyl coenzyme A (MCoA) were aimed at mimicking the influence of environmental pathogens on plants in their natural habitats and at provoking exogenous induction of the phenylpropanoid pathway. The elicitors’ indanoyl-isoleucine (IN), N-linolenoyl-L-glutamine (LG) and insect saliva (IS), as well as malonyl coenzyme A (MCoA), were independently inoculated to stimulate the synthesis of phenylpropanoids. All of the enhancers positively increased the concentration of phenolic compounds in grape cells. The highest concentration of phenolic acids was detected after 2 h for MCoA, after 48 h for IN and after 24 h for LG and IS respectively. At the maximum production time, treated grape cells had a 3.5-fold (MCoA), 1.6-fold (IN) and 1.5-fold (IS) higher phenolic acid content compared to the corresponding control samples. The HPLC results of grape cells showed two major resveratrol derivatives: 3-O-Glucosyl-resveratrol and 4-(3,5-dihydroxyphenyl)-phenol. Their influences of the different elicitors, time of harvest and biomass concentration (p < 0.0001) were statistically significant on the synthesis of phenolic compounds. The induction with MCoA was found to demonstrate the highest statistical effect corresponding to the strongest stress response within the phenylpropanoid pathway in grape cells.

Abstract: The major anthocyanin in A. thaliana is a cyanidin derivative modified by glycosylation as well as by the addition of three acyl moieties: malonyl, p-coumaroyl, and sinapoyl. We have isolated a member of the BAHD acyltransferase family which catalyzes this malonylation reaction by combining a reverse genetics approach with biochemical genomics. A mutant line containing a T-DNA insertion in At3g29590, the gene encoding the malonylating enzyme, is incapable of producing malonylated anthocyanins. Transgenic plants harboring an RNAi silencing cassette for At3g29590 demonstrate a positive correlation between reduction in the At3g29590 gene transcript and the decrease of malonylated anthocyanins. Transcript levels for both At3g29590 and the epistatic gene At4g14090, encoding 5-O-anthocyanin glucosyltransferase, increase in several plant lines as they accumulate anthocyanin pigments. Investigation of the heterologously expressed and purified malonylating enzyme showed that the activity is specific for malonyl-CoA and for anthocyanins with 5-O-glucosylation. The malonyl transfer itself occurs only to the 5-O-glucoside function, and not to any of the other sugar moieties present in A. thaliana anthocyanins. Hence, both in vivo and in vitro results define the activity of the At3g29590-encoded enzyme as an anthocyanin 5-O-glucoside-6″-O-malonyltransferase (At5MAT). [Copyright &y& Elsevier]

There seems to be an association between increased concentrations of malonyl coenzyme A (malonyl CoA) in skeletal muscle and diabetes and/or insulin resistance. The purpose of the current study was to test the hypothesis that treatments designed to manipulate malonyl CoA concentrations would affect insulin-stimulated glucose transport in cultured C2C12 myotubes. We assessed glucose transport after polyamine-mediated delivery of malonyl CoA to myotubes, after incubation with dichloroacetate (which reportedly increases malonyl CoA levels), or after exposure of myotubes to 2-bromopalmitate, a carnitine palmitoyl transferase I inhibitor. All three of these treatments prevented stimulation of glucose transport by insulin. We also assayed glucose transport after 30 min of inhibition of acetyl coenzyme A carboxylase (ACC), the enzyme which catalyzes the production of malonyl CoA. Three unrelated ACC inhibitors (diclofop, clethodim, and Pfizer CP-640186) all enhanced insulin-stimulated glucose transport. However, none of the treatments designed to manipulate malonyl CoA concentrations altered markers of proximal insulin signaling through Akt. The findings support the hypothesis that acute changes in malonyl CoA concentrations affect insulin action in muscle cells but suggest that the effects do not involve alterations in proximal insulin signaling. [ABSTRACT FROM AUTHOR]

Abstract: The pathogenesis of alcoholic steatosis is a complex process that is manifested through several mechanisms involving some of or all the following body metabolism components: increased fat synthesis, increased mobilization of depot fat, defective export of fat from the liver, and decreased fat breakdown. Some of the novel findings in these mechanisms involve the down-regulation of peroxisome proliferator-activated receptor alpha and up-regulation of lipogenic enzymes through the induction of sterol regulatory element-binding protein. Yet another mechanism that remains viable is the adenosine 5′-monophosphate–activated protein kinase, which, through a complex mechanism, may regulate the relative concentrations of intracellular malonyl coenzyme A and long-chain acyl-coenzyme A, the key metabolites responsible for the balance between fat synthesis versus degradation pathways. Finally, excess dietary intake of omega-6 polyunsaturated fatty acids may exacerbate alcohol-induced onset of hepatic steatosis and alcoholic liver disease. This may explain why supplementation with lecithin containing omega-6 polyunsaturated fatty acids in a recent clinical trial in human beings failed to show any beneficial effects, although it was partially effective in an animal model. In contrast, dietary intake of omega-3 polyunsaturated fatty acids in moderation may have a protective effect against steatosis and alcoholic liver disease. [Copyright &y& Elsevier]

Abstract An increasing body of evidence has revealed that activation of adenosine monophosphate (AMP)-activated protein kinase (AMPK)-activated protein kinase increases fatty acid oxidation by lowering the concentration of malonyl coenzyme A (CoA), an inhibitor of carnitine palmitoyl transferase 1. Studies carried out primarily in skeletal muscle suggest that AMPK modulates the concentration of malonyl CoA by concurrently phosphorylating and inhibiting acetyl CoA carboxylase (ACC), the rate limiting enzyme in malonyl CoA synthesis, and phosphorylating and activating malonyl CoA decarboxylase (MCD), an enzyme involved in its degradation. We have recently observed that AMPK and MCD activities are increased and ACC activity diminished in skeletal muscle, liver and, surprisingly, in adipose tissue 30 min following exercise (treadmill run) in normal rats. In liver and adipose tissue these changes were associated with a decrease in the activity of glycerol-3-phosphate acyltransferase (GPAT), which catalyses the first committed reaction in glycerolipid synthesis and, which like ACC, is phosphorylated and inhibited by AMPK. Similar changes in ACC, MCD and GPAT were observed following the administration of 5-aminoimidazole 4-carboxamide-riboside (AICAR), further indicating that the exercise-induced alterations in these enzymes were AMPK-mediated. Conclusions: (1) AMPK plays a major role in regulating lipid metabolism in multiple tissues following exercise. (2) The net effect of its activation is to increase fatty acid oxidation and diminish glycerolipid synthesis. (3) The relevance of these findings to the regulation of muscle glycogen repletion in the post-exercise state and to the demonstrated ability of AMPK activation to decrease adiposity and increase insulin sensitivity in rodents remains to be determined. [ABSTRACT FROM AUTHOR]

Malonyl coenzyme A is synthesized by transacylating S-malonyl-N-decanoyl cysteamine with coenzyme A. A simplified procedure for the preparation of S-malonyl-N-decanoyl cysteamine, using cysteamine as starting material, is described.