Carboxylic Diacids Research Articles

Multidisciplinary Team of Chemists and Geneticists Working to Reclaim Value Embedded in Plastics.

This invited Team Profile was created by Clay C. C. Wang. He and his collaborators recently published an article on the conversion of polyethylenes to fungal secondary metabolites. First, the team employs an oxidative catalytic process, highly tolerant of impurities, to degrade post-consumer polyethylenes to carboxylic diacids. Then, they utilize engineered strains of the fungus Aspergillus nidulans to convert these diacids to structurally diverse and pharmacologically active secondary metabolites. "Conversion of Polyethylenes into Fungal Secondary Metabolites", C. Rabot, Y. Chen, S. Bijlani, Y.-M. Chiang, C. E. Oakley, B. R. Oakley, T. J. Williams, C. C. C. Wang, Angew. Chem. Int. Ed. 2023, e202214609; Angew. Chem. 2023, e202214609.

Multidisciplinary Team of Chemists and Geneticists Working to Reclaim Value Embedded in Plastics

AbstractThis invited Team Profile was created by Clay C. C. Wang. He and his collaborators recently published an article on the conversion of polyethylenes to fungal secondary metabolites. First, the team employs an oxidative catalytic process, highly tolerant of impurities, to degrade post‐consumer polyethylenes to carboxylic diacids. Then, they utilize engineered strains of the fungus Aspergillus nidulans to convert these diacids to structurally diverse and pharmacologically active secondary metabolites. “Conversion of Polyethylenes into Fungal Secondary Metabolites”, C. Rabot, Y. Chen, S. Bijlani, Y.‐M. Chiang, C. E. Oakley, B. R. Oakley, T. J. Williams, C. C. C. Wang, Angew. Chem. Int. Ed. 2023, e202214609; Angew. Chem. 2023, e202214609.

Polystyrene Upcycling into Fungal Natural Products and a Biocontrol Agent.

Polystyrene (PS) is one of the most used yet infrequently recycled plastics. Although manufactured on the scale of 300 million tons per year globally, current approaches toward PS degradation are energy- and carbon-inefficient, slow, and/or limited in the value that they reclaim. We recently reported a scalable process to degrade post-consumer polyethylene-containing waste streams into carboxylic diacids. Engineered fungal strains then upgrade these diacids biosynthetically to synthesize pharmacologically active secondary metabolites. Herein, we apply a similar reaction to rapidly convert PS to benzoic acid in high yield. Engineered strains of the filamentous fungus Aspergillus nidulans then biosynthetically upgrade PS-derived crude benzoic acid to the structurally diverse secondary metabolites ergothioneine, pleuromutilin, and mutilin. Further, we expand the catalog of plastic-derived products to include spores of the industrially relevant biocontrol agent Aspergillus flavus Af36 from crude PS-derived benzoic acid.

Conversion of Polyethylenes into Fungal Secondary Metabolites.

Waste plastics represent major environmental and economic burdens due to their ubiquity, slow breakdown rates, and inadequacy of current recycling routes. Polyethylenes are particularly problematic, because they lack robust recycling approaches despite being the most abundant plastics in use today. We report a novel chemical and biological approach for the rapid conversion of polyethylenes into structurally complex and pharmacologically active compounds. We present conditions for aerobic, catalytic digestion of polyethylenes collected from post-consumer and oceanic waste streams, creating carboxylic diacids that can then be used as a carbon source by the fungus Aspergillus nidulans. As a proof of principle, we have engineered strains of A. nidulans to synthesize the fungal secondary metabolites asperbenzaldehyde, citreoviridin, and mutilin when grown on these digestion products. This hybrid approach considerably expands the range of products to which polyethylenes can be upcycled.

Conversion of Polyethylenes into Fungal Secondary Metabolites

AbstractWaste plastics represent major environmental and economic burdens due to their ubiquity, slow breakdown rates, and inadequacy of current recycling routes. Polyethylenes are particularly problematic, because they lack robust recycling approaches despite being the most abundant plastics in use today. We report a novel chemical and biological approach for the rapid conversion of polyethylenes into structurally complex and pharmacologically active compounds. We present conditions for aerobic, catalytic digestion of polyethylenes collected from post‐consumer and oceanic waste streams, creating carboxylic diacids that can then be used as a carbon source by the fungus Aspergillus nidulans. As a proof of principle, we have engineered strains of A. nidulans to synthesize the fungal secondary metabolites asperbenzaldehyde, citreoviridin, and mutilin when grown on these digestion products. This hybrid approach considerably expands the range of products to which polyethylenes can be upcycled.

Construction of super-hydrophobic hypercrosslinked porous polymers for selectively removing aromatic diamines from the polyurethane bio-hydrolysate

The upcycling of Polyurethane (PU) degradation products has been gaining tremendous attention and research interest in recent years. In particular, due to the toxicity to microorganisms, the key process is to remove aromatic diamines selectively and efficiently from the bio-hydrolysate which also includes multiple carboxylic diacids and polyols. Herein, a series of super-hydrophobic hypercrosslinked porous polymers (HCPPs) were prepared to selectively remove aromatic diamines in a neutral condition. They were facially fabricated via Friedel-Crafts alkylation reactions with benzene and three types of benzyl bromides. Besides, the surface area, porous structure, and hydrophobic properties of resulting polymers were adjusted by changing the length and connected nodes numbers of crosslinkers. Particularly, HCPP-TBMB knitted by 1,3,5-tris(bromomethyl)-benzene (TBMB) owned a maximum BET surface area of 1048.8 m2 g−1 with hierarchical porosity, as well as high thermal stability and super-hydrophobicity. The adsorption experiments on HCPP-TBMB clarified the large adsorption capacities of 2,4-toluene diamine (TDA, 1.062 mmol g−1) and 4,4′-methylene dianiline (MDA, 1.971 mmol g−1) as well as high selectivity in the model PU hydrolysate. Moreover, thermodynamic experiments and spectral analysis revealed the physical adsorption process for uptake of aromatic diamines on HCPP-TBMB. The main adsorption mechanism contained π-π stacking, hydrophobic interaction, and hole size effect. These findings may provide a promising strategy for highly selective removal of aromatic diamines from the PU bio-hydrolysate.

Plasmonic nanoprobes gauging the length and flexibility of α,ω-Alkanedicarboxylic acids with an optical readout

Discrimination of chemical homologs, compounds differing by the number of repeating units, given their similitude, is non-trivial, and therefore needs unconventional approaches. Herein, by taking advantage of the difference in length and utilizing plasmon coupling, we present the recognition of a sequence of linear saturated carboxylic diacids that occur naturally and accompany us in everyday life. The interactions between these diacids and gold nanoparticles, the surface of which is covered by cationic pillar[n]pyridinium macrocycles, produce a multilevel response, including a color that can be watched with an unaided eye. This method of recognition seems to be universal for anionic species and can be potentially extended to other sorts of molecular similarity and isomerism.

Synthesis and characterisation of bio-based polyester materials from vegetable oil and short to long chain dicarboxylic acids

Polyester-type polymers were efficiently prepared from broccoli seed oil and several carboxylic diacids. The polyesters were prepared through a simple two-step process including oxidation of the insaturations to oxiranes followed by ring opening with dicarboxylic acids under basic conditions. Eight polymer materials derived from different fatty diacids (from 5C to 16C) and an aromatic diacid were prepared and characterised. Rubber-type crosslinked biobased materials exhibited low Tg values comprised between −5 and +5°C depending on the diacid type and length.

Reaction of uranyl nitrate with carboxylic diacids under hydrothermal conditions. Crystal structure of complexes with l(+)-tartaric and oxalic acids

l(+)-tartaric acid reacts with uranyl nitrate in the presence of KOH, under mild hydrothermal conditions, to give the complex [UO 2(C 4H 4O 6)(H 2O)] ( 1), the first uranyl tartrate to be crystallographically characterized. Each tartrate ligand bridges three uranyl ions, one of them in chelating fashion through proximal carboxylate and hydroxyl groups. The resulting assemblage is two-dimensional, with the uranyl pentagonal bipyramidal coordination polyhedra separated from one another. Prolonged heating of an uranyl tartrate solution resulted in oxidative cleavage of the acid and formation of the oxalate complex [(UO 2) 2(C 2O 4) 2(OH)Na(H 2O) 2] ( 2). The bis-bidentate oxalate and bridging hydroxide groups ensure the formation of sheets with corner-sharing uranyl pentagonal bipyramidal coordination polyhedra, in which six-membered metallacycles encompass the sodium ions. These sheets are assembled into a three-dimensional framework through further oxo-bonding of the sodium ions.

“Sweet Silicones”: Biocatalytic Reactions to Form Organosilicon Carbohydrate Macromers

Immobilized lipase B from Candida antarctica (Novozyme 435) catalyzed the regioselective formation of ester bonds between organosilicon carboxylic diacids and a C1-O-alkylated sugar under mild reaction conditions (i.e., low temperature, neutral pH, solventless). Specifically, the acid-functionalized organosilicones reacted with the primary hydroxyl group at the C6 position of alpha,beta-ethyl glucoside during the regioselective esterification. The pure organosilicon-sugar conjugates were prepared in a one-step reaction without protection-deprotection steps and without activation of the acid groups with the integrity of the siloxane bonds. [reaction: see text]

Graphite-Supported Ketodecarboxylation of Carboxylic Diacids

Graphite-Supported Ketodecarboxylation of Carboxylic Diacids

ChemInform Abstract: Graphite‐Supported Ketodecarboxylation of Carboxylic Diacids.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

New polyamides with long alkane segments: nylon 6.24 and 6.34

A series of new amphiphilic, semi-crystalline polyamides based on hexamethylenediamine and long alkane carboxylic diacids has been synthesized and characterized, here exemplified by polyamide 6.24 (PA-6.24) and polyamide 6.34 (PA-6.34). The polymers were produced by melt polycondensation, which yielded materials of weight-average molecular weights in the range of 30,000–35,000 g/mol. The thermal properties of the polyamides were investigated by various thermo-analytical methods. PA-6.24 and PA-6.34 exhibit relatively high melting temperatures of 189 and 177°C, respectively. Both materials display rather poor solubility in solvents that are used for common polyamides, but by contrast, dissolve in, e.g. ethanesulfonic acid. PA-6.34 was found to aggregate in dilute methanesulfonic acid solutions and form thermo-reversible gels in H 2SO 4, which we attribute to its amphiphilic character. The latter enabled the use of PA-6.34 as a “compatibilizer” for blends of polyolefins and polyamides. Finally, the Young's moduli of isotropic films of PA-6.24 and PA-6.34 were determined to be 1.3 and 0.7 GPa, respectively, representing a stiffness that is intermediate between that of common polyamides and polyethylene.

Oxidation with air of cyclohexanone to carboxylic diacids on carbon catalysts

Carbons derived from phenolic resins were used as catalysts for the aqueous phase oxidation of cyclohexanone at 140°C under air pressure. The reaction yielded mainly adipic, glutaric and succinic acids. The samples were modified by heat treatments in CO2, air or N2 at different temperatures and characterized to determine their surface area and porosity and to evaluate the functional groups on the surface. Treatments under CO2 or air increased the oxidation activity. The selectivity to adipic acid was maximum (33%) after activation in air which greatly increased the surface concentration of oxygen-containing functional groups. However, it was not possible to attribute the selectivity to specific acidic, neutral or basic groups present at the surface of carbons.

ChemInform Abstract: Molecular Recognition: Size and Shape Specificity in the Binding of Dicarboxylic Acids.

AbstractThe mode of interaction of carboxylic diacids with the enzyme model receptors (I) is studied.