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Our computational analysis suggests that, upon photoswitching, the nature of the homoaromatic state changes in its perimeter from a more pronounced local 6π homoaromatic state to a global 10π homoaromatic state. These demonstrations of stable and accessible homoaromatic neutral hydrocarbons and their photoswitching behaviour provide new understanding and insights into the study of homoconjugative interactions in organic molecules, and for the design of new responsive molecular materials.Engineering Acinetobacter baylyi ADP1 for mevalonate production from Utilization of lignin, an abundant renewable resource, is limited by its heterogenous composition and complex structure. Biological valorization of lignin provides advantages over traditional chemical processing as it occurs at ambient temperature and pressure and does not use harsh chemicals. Furthermore, the ability to biologically funnel heterogenous substrates to products eliminates the need for costly downstream processing and separation of feedstocks. However, lack of relevant metabolic networks and low tolerance to degradation products of lignin limits the application of traditional engineered model organisms.
To circumvent this obstacle, we employed Acinetobacter baylyi ADP1, which natively catabolizes lignin-derived aromatic substrates through the β-ketoadipate pathway, to produce mevalonate from lignin-derived compounds. We enabled expression of the mevalonate pathway in ADP1 and validated activity in the presence of multiple lignin-derived aromatic substrates. Furthermore, by knocking out wax ester synthesis and utilizing fed-batch cultivation, we improved mevalonate titers 7-fold to 1014 mg/L (6 mM). This work establishes a foundation and provides groundwork for future efforts to engineer improved production of mevalonate and derivatives from lignin-derived aromatics using Effect of Aromatic Amines on the Properties of Formaldehyde-Based Xerogels.This study investigates the synthesis of formaldehyde-based xerogels using alternative aromatic precursors, with comparison to traditional resorcinol-formaldehyde analogues, in order to alter the chemical composition of the resulting gels. By replacing resorcinol with aromatic amine molecules, i.e.
, ammeline, melamine and melem, each expected to undergo similar reactions with formaldehyde as the substituted species, we found that for all substituted gels, at low additive contents, the gel structure was compromised and non-porous materials were formed, as opposed to the most abundant monomers, and therefore, these additives seem to act as impurities at low levels. Working towards cyanocobalamin salcaprozate , melem monomers exhibited low solubility (~5%), even at elevated temperatures, thereby limiting the range to which melem could act as a substitute, while melamine could be incorporated up to ~40% under acidic conditions, with enhanced microporosity over this range. Pure gels were successfully synthesised from ammeline, but their performance was inferior to resorcinol-formaldehyde gels, while melamine-formaldehyde analogues required acidic reaction conditions but shrank considerably on sub-critical drying, adversely affecting the gel properties and demonstrating their lack of potential as sorbents. This demonstrates the potential for the inclusion of aminated aromatics within resorcinol-based gel systems, however, only as partial substitutes and not complete replacements.Biocatalytic syntheses of aromatics from D-glucose: renewable microbial sources Chemistry is moving into a new era in which renewable resources and starting materials such as D-glucose will likely be prominent features of industrial chemical manufacture. The keys to this progress are the design, development, and use of microbial biocatalysts. Aromatic biosynthesis serves as a paradigm for how biocatalysts can be manipulated to achieve the yield, rate, and purity criteria central to chemical manufacture.
A disproportionate amount of the metabolic carbon flow of the biocatalyst must first be directed into the common pathway of aromatic amino acid biosynthesis. This review describes ways of achieving this goal through the traditional strategy of manipulating the catalytic activity of the first enzyme in the common pathway, as well as the amelioration of limitations in the in vivo availability of common-pathway enzyme substrates. The inability of individual enzymes to convert their substrate to product fast enough to avoid substrate accumulation further impedes carbon flow through the common pathway. Seebio cyanocobalamin salcaprozate sodium discusses identification and removal of these rate-limiting enzymes. Finally, we examine the creation of heterologous biocatalysts and how biocatalysis could be integrated with traditional chemical transformations to expand the number of organic chemicals Reversible Photooxygenation of Anthracene Carboxyimide for Singlet Oxygen Formation: Mechanistic Study and Efficient Nitrite Detection.Corpus Christi, 6300 Ocean Dr, Corpus Christi, Texas, 78412, USA.
