Malonic acid

Phase State Regulates Photochemical HONO Production from NaNO(3)/Dicarboxylic Acid Mixtures.[Pubmed:38629947]

Environ Sci Technol. 2024 Apr 30;58(17):7516-7528.

Field observations of daytime HONO source strengths have not been well explained by laboratory measurements and model predictions up until now. More efforts are urgently needed to fill the knowledge gaps concerning how environmental factors, especially relative humidity (RH), affect particulate nitrate photolysis. In this work, two critical attributes for atmospheric particles, i.e., phase state and bulk-phase acidity, both influenced by ambient RH, were focused to illuminate the key regulators for reactive nitrogen production from typical internally mixed systems, i.e., NaNO(3) and dicarboxylic acid (DCA) mixtures. The dissolution of only few oxalic acid (OA) crystals resulted in a remarkable 50-fold increase in HONO production compared to pure nitrate photolysis at 85% RH. Furthermore, the HONO production rates (P(HONO)) increased by about 1 order of magnitude as RH rose from <5% to 95%, initially exhibiting an almost linear dependence on the amount of surface absorbed water and subsequently showing a substantial increase in P(HONO) once nitrate deliquescence occurred at approximately 75% RH. NaNO(3)/Malonic acid (MA) and NaNO(3)/succinic acid (SA) mixtures exhibited similar phase state effects on the photochemical HONO production. These results offer a new perspective on how aerosol physicochemical properties influence particulate nitrate photolysis in the atmosphere.

Boosting the Reactivity of Bis-Lactones to Enable Step-Growth Polymerization at Room Temperature.[Pubmed:38616811]

Macromolecules. 2024 Mar 22;57(7):3319-3327.

The development of new sustainable polymeric materials endowed with improved performances but minimal environmental impact is a major concern, with polyesters as primary targets. Lactones are key monomers thanks to ring-opening polymerization, but their use in step-growth polymerization has remained scarce and challenging. Herein, we report a powerful bis(gamma-lactone) (gammaSL) that was efficiently prepared on a gram scale from Malonic acid by Pd-catalyzed cycloisomerization. The gamma-exomethylene moieties and the spiro structure greatly enhance its reactivity toward ring-opening and enable step-growth polymerization under mild conditions. Using diols, dithiols, or diamines as comonomers, a variety of regioregular (AB)(n) copolymers with diverse linkages and functional groups (from oxo-ester to beta-thioether lactone and beta-hydroxy-lactame) have been readily prepared. Reaction modeling and monitoring revealed the occurrence of an original trans-lactonization process following the first ring-opening of gammaSL. This peculiar reactivity opens the way to regioregular (ABAC)(n) terpolymers, as illustrated by the successive step-growth polymerization of gammaSL with a diol and a diamine.

Determination of trace chelating carboxylic acids in rice by green extraction combined with liquid chromatography-mass spectrometry analysis and its application in the evaluation of old and new rice.[Pubmed:38572671]

Rapid Commun Mass Spectrom. 2024 Jun 15;38(11):e9738.

RATIONALE: Accurate identification of old rice samples from new ones benefits their market circulation and consumers. However, the current detection methods are still not satisfactory because of their insufficient accuracy or (and) time-consuming process. METHODS: Chelating carboxylic acids (CCAs) were selectively extracted from rice, by stirring with chelating resin and a dilute Na(2)CO(3) solution. The green analytical chemistry guidelines for sample preparation were investigated by using the green chemistry calculator AGREE prep. The extractant was determined by liquid chromatography-mass spectrometry (LC/MS), and statistical analysis of the analytical data was carried out to evaluate the significance of the difference by ChiPlot. RESULTS: The limit of quantitation for the CCAs is in the range of 1 to 50 ng/mL, with a reasonable reproducibility. The CCAs in 23 rice samples were determined within a wide concentration range from 0.03 to 1174 mug/g. Intriguingly, the content of citric acid, Malonic acid, alpha-ketoglutaric acid and cis-aconite acid in new rice was each found to be distinctively higher than that in old rice by several times. Even mixtures of old and new rice were found to show much difference in the concentration of citric acid and malic acid. CONCLUSION: A green analytical method has been developed for the simultaneous determination of CCAs by LC/MS analysis, and the identification of old rice samples from new ones was easily carried out according to their CCA content for the first time. The results indicated that the described method has powerful potential for the accurate identification of old rice samples from new ones.

Qualitative and Quantitative Metabolite Comparison of Korean Traditional Alcoholic Beverages: Takju, Yakju, and Traditional-Soju.[Pubmed:38540946]

Foods. 2024 Mar 21;13(6):956.

With increasing interest in Korean foods and beverages, Korean traditional alcoholic beverages need to be studied. To characterize Korean traditional alcoholic beverages, we analyzed the metabolites of Takju, Yakju, and Traditional-Soju using 48 commercial products. We performed non-targeted metabolite profiling using gas chromatography time-of-flight mass spectrometry (GC-TOF-MS) and identified 33 significantly discriminant metabolites, including nine organic acids, three amino acids, and seven fatty acids, in the three types of alcoholic beverage. Subsequently, we quantified the profiled metabolites in each product and compared their contents to identify alcoholic beverage type-specific metabolites. Thus, we figured out seven metabolites using receiver operating characteristic (ROC) curves. The results revealed that octadecanoic acid (limit of detection (LOD) to 168.72 mg/L), nonanoic acid (LOD to 112.54 mg/L), and octanoic acid (8.00 to 145.08 mg/L) in Takju; succinic acid (LOD to 1.90 mg/mL), heptanoic acid (LOD to 343.23 mg/L), and hexadecanoic acid (20.28 to 126.45 mg/L) in Yakju; and Malonic acid (LOD to 19.13 mg/mL) in Traditional-Soju, with an area under the curve (AUC) > 0.7, are important metabolites that can distinguish the type of alcoholic beverage. Our results provide qualitative and quantitative metabolite information about Korean traditional alcoholic beverages that can be used by consumers and manufacturers.

Organocatalytic enantioselective decarboxylative protonation of alpha-alkyl-alpha-aryl malonate monoesters.[Pubmed:38497353]

Chem Commun (Camb). 2024 Apr 2;60(28):3854-3857.

In contrast to the well-established enzymatic enantioselective decarboxylative protonation (EDP), the corresponding chemocatalytic reactions of acyclic Malonic acid derivatives remain challenging. Herein, we developed a biomimetic EDP of alpha-alkyl-alpha-aryl malonate monoesters using a chiral 1,2-trans-diaminocyclohexane-based N-sulfonamide as an organocatalyst. The method demonstrates excellent chemical yields, good enantioselectivity, mild reaction conditions, and the generation of only CO(2) as waste.

[Pollution Characteristics，Sources，and Secondary Generation of Organic Acids in PM(2.5) in Zhengzhou].[Pubmed:38471910]

Huan Jing Ke Xue. 2024 Feb 8;45(2):700-708.

Organic acids in atmospheric particulate matter are widely involved in various physical and chemical reactions in the atmosphere and contribute greatly to the formation of secondary organic aerosols and haze pollutions. Therefore， the concentration distribution characteristics， sources， and secondary formation of organic acids in particulate matter are of great significance for further investigation of organic aerosols and their secondary transformation. Fine particulate matter （PM(2.5)） samples were collected in Zhengzhou， and three types of organic acids， including dicarboxylic acids， fatty acids， and resin acids， were analyzed to explore their species distribution， seasonal variations， source contribution， and secondary generation. Malonic acid （di-C(3)） and succinate acid （di-C(4)） were the most abundant in the identified dicarboxylic acids， which showed obvious seasonal variations in the order of summer > autumn > winter > spring. Fatty acids had the highest concentration in winter and the lowest concentration in spring， showing obvious bimodal advantages， with the most abundant compounds being palmitic acid and stearic acid （C(18)）. Principal component analysis and multiple linear regression （MLR） were used to analyze the source of organic acids in PM(2.5) in Zhengzhou； the results showed that 35% of the organic acids came from combustion and traffic sources， 24% from cooking sources， 23% from secondary formation， and 17% from natural sources. The ratios of the selected marker species （i.e.， di-C(3) / di-C(4)， F/M， and C(18：1) / C(18)） were used as tracers for the secondary formation of the organic aerosol and its aging process. The results showed that the photochemical reaction was intense in summer， and the proportion of organic aerosol aging or secondary production was high， whereas the photochemical reaction was weak in winter， and the aging degree of organic aerosol was low. Correlation analysis and MLR were used in combination to quantify the relative contribution of gas-phase oxidation and liquid-phase oxidation to dicarboxylic acid formation， and the results showed that gas-phase oxidation played a dominant role in the sampling period （accounting for 58%）， especially in summer （61%）.

Cocrystallization improves the tabletability of ligustrazine despite a reduction in plasticity.[Pubmed:38417726]

Int J Pharm. 2024 Apr 10;654:123939.

Cocrystallization is an effective method for altering the tableting performance of crystals by modifying their mechanical properties. In this study, cocrystals of ligustrazine (LIG) with Malonic acid (MA) and salicylic acid (SA) were investigated to better understand how modifying crystal structure can affect tableting properties. LIG suffered from overcompression at high pressures despite its high plasticity. Both LIG-MA and LIG-SA displayed lower plasticity than LIG, which was confirmed by both an in-die Heckel and energy framework analyses. The LIG-MA cocrystal displayed slightly worse tabletability than LIG, as expected from its lower plasticity. However, LIG-SA surprisingly showed improved tabletability despite its lower plasticity. This was explained by the higher bonding strength of LIG-SA compared with LIG. This work not only provided new examples of tabletability modulation through crystal engineering but also highlighted the risk of failed tabletability predictions based on plasticity alone. Instead, more reliable tabletability predictions of different crystal forms must consider the bonding area - bonding strength interplay.

Translational and reorientational dynamics in carboxylic acid-based deep eutectic solvents.[Pubmed:38380750]

J Chem Phys. 2024 Feb 21;160(7):074503.

The glass formation and the dipolar reorientational motions in deep eutectic solvents (DESs) are frequently overlooked, despite their crucial role in defining the room-temperature physiochemical properties. To understand the effects of these dynamics on the ionic conductivity and their relation to the mechanical properties of the DES, we conducted broadband dielectric and rheological spectroscopy over a wide temperature range on three well-established carboxylic acid-based natural DESs. These are the eutectic mixtures of choline chloride with oxalic acid (oxaline), Malonic acid (maline), and phenylacetic acid (phenylaceline). In all three DESs, we observe signs of a glass transition in the temperature dependence of their dipolar reorientational and structural dynamics, as well as varying degrees of motional decoupling between the different observed dynamics. Maline and oxaline display a breaking of the Walden rule near the glass-transition temperature, while the relation between the dc conductivity and dipolar relaxation time in both maline and phenylaceline is best described by a power law. The glass-forming properties of the investigated systems not only govern the orientational dipolar motions and rheological properties, which are of interest from a fundamental point of view, but they also affect the dc conductivity, even at room temperature, which is of high technical relevance.

Feeding a Saccharomyces cerevisiae fermentation product during a gut barrier challenge in lactating Holstein cows impacts the ruminal microbiota and metabolome.[Pubmed:38369118]

J Dairy Sci. 2024 Feb 16:S0022-0302(24)00489-2.

Through its influence on the gut microbiota, feeding of Saccharomyces cerevisiae fermentation products (SCFP) has been a successful strategy to enhance the health of dairy cows during periods of physiological stresses. Although production and metabolic outcomes from feeding SCFP are well-known, combined impacts on the ruminal microbiota and metabolome during gut barrier challenges remain unclear. To address this gap in knowledge, multiparous Holstein cows (97.1 +/- 7.6 DIM; n = 8/group) fed a control diet (CON) or CON plus 19 g/d SCFP for 9 wk were subjected to a feed restriction (FR) challenge for 5 d, during which they were fed 40% of their ad-libitum intake from the 7 d before FR. DNA extracted from ruminal fluid was subjected to PacBio Full-Length 16S rRNA gene sequencing, RT-PCR of 12 major ruminal bacteria, and metabolomics analysis of up to 189 metabolites via GC-MS. High-quality amplicon sequence analyses were performed with Targeted Amplicon Diversity Analysis (TADA), MicrobiomeAnalyst, PICRUSt2, and STAMP software, while metabolomics data were analyzed via MetaboAnalyst 5.0. Ruminal fluid metabolites from the SCFP group exhibited a greater alpha diversity Chao 1 (P = 0.03) and Shannon indices (P = 0.05), and the PLS-DA analysis clearly discriminated metabolite profiles between dietary groups. The abundance of CPla_4_termite_group, Candidatus_Saccharimonas, Oribacterium, and Pirellula genus in cows fed SCFP was greater. In the SCFP group, concentrations of ethanolamine, 2-amino-4,6-dihydroxypyrimidine, glyoxylic acid, serine, threonine, cytosine, stearic acid, and pyrrole-2-carboxylic acid were greater in ruminal fluid. Both Fretibacterium and Succinivibrio abundance were positively correlated with metabolites across various biological processes: gamma-aminobutyric acid, galactose, butane-2,3-diol, fructose, 5-amino pentanoic acid, beta-aminoisobutyric acid, ornithine, Malonic acid, 3-hydroxy-3-methylbutyric acid, hexanoic acid, heptanoic acid, cadaverine, glycolic acid, beta-alanine, 2-hydroxybutyric acid, methyl alanine, and alanine. In the SCFP group, compared with CON, the mean proportion of 14 predicted pathways based on metabolomics data was greater, while 10 predicted pathways were lower. Integrating metabolites and upregulated predicted enzymes (NADP+-dependent glucose-6-phosphate dehydrogenase, 6-phosphogluconate dehydrogenase, serine: glyoxylate aminotransferase, and D-glycerate 3-kinase) indicated that the pentose phosphate pathway and photorespiration pathway were most upregulated by SCFP. Overall, SCFP during FR led to alterations in ruminal microbiota composition and key metabolic pathways. Among those, there was a shift from the tricarboxylic acid (TCA) cycle to the glyoxylate cycle and nitrogenous base production was enhanced.

Molecular marker identification, antioxidant, antinociceptive, and anti-inflammatory responsiveness of malonic acid capped silver nanoparticle.[Pubmed:38357362]

Front Pharmacol. 2024 Jan 31;14:1319613.

Nano-sized silver has drawn a great deal of attention in the field of health sciences owing to its remarkable therapeutic applications. Interestingly, the method applied to synthesize nanoparticles and the choice of reagents considerably influence their therapeutic potential and toxicities. Current research has explored the toxicity, anti-inflammatory, antinociceptive, and antioxidant responses of the Malonic acid-capped silver nanoparticles (MA-AgNPs (C) by using sodium borohydride as a reducing agent at low temperatures by employing both in vitro and in vivo approaches. Furthermore, it has highlighted the synergistic effect of these novel compounds with conventional anti-inflammatory therapeutic agents. Acute and sub-acute toxicity analysis performed following OECD guidelines showed that the studied MA-AgNPs (C) are safer, and prominent toxic signs have not been detected at the highest studied dose of 2,000 mg/kg. Cytotoxicity evaluation through brine shrimp lethality revealed 20% lethality at the highest concentration of 169.8 mug/mL. Significantly, positive anti-inflammatory and analgesic responses alone as well as synergism with the standard were identified through in vitro as well as in vivo methods which were more potent at a lower dose (200 mg/kg). Notably synergistic outcomes were more pronounced than individual ones, indicating their prominent effect as a feasible drug delivery system. IL-6 and TNF-alpha assessment in excised paw tissue through RTPCR technique further supported their anti-inflammatory potential. DPPH assay revealed eminent in vitro antioxidant activity which was further corroborated by in vivo antioxidant assessment through evaluation of SOD in excised paw tissue.

Exploring gender-based diversity for phenolic and organic acid profiles in the genetic resource of betel vine (Piper betle L.) from India as revealed through high-performance liquid chromatography (HPLC-DAD).[Pubmed:38351909]

3 Biotech. 2024 Mar;14(3):65.

Betel vine (Piper betle L.) is a dioecious plant and has paved way for researchers to explore the available genetic resources for the biochemical compounds. In the study, twenty sexually dimorphic genotypes of betel vine were characterized for bio-compounds using high-performance liquid chromatography (HPLC-DAD), and as a result identified phenolic compounds and organic acids, including caffeic acid, salicylic acid, t-ferulic acid, sinapic acid, p-coumaric acid, t-cinnamic acid, gallic acid, p-hydroxybenzoic acid, gluconic acid, oxalic acid, lactic acid, tartaric acid, Malonic acid, citric acid, and succinic acid. The phenolics and organic acids in the male genotypes were more than the female genotypes; this insight of phytochemicals variability could aid in the gender differences. However, the highest phenolic contents was found in the Kapoori Chintalapudi (68.77 mg/100 g), followed by Kapoori Bihar (67.03 mg/100 g) and Ghanegatte (63.31 mg/100 g) genotypes. The abundance of biomolecules was found in the order, namely gallic acid, sinapic acid, caffeic acid, tartaric acid, citric acid, and Malonic acid in regardless of gender. The chemical profile of sexual dimorphs in betel vine and serve as a possible index for gender differentiation. The principal component analysis showed the hierarchical grouping of the genotypes based on the phenolic compounds and organic acids; thereby the divergent genotypes Kapoori Chintalapudi, Ghanaghette, Kapoori Bihar, and Sirugamani-1 were identified for phenolic acid richness. Similarly, CARI-6, Halisahar Sanchi, Kapoori Bihar, and Gangarampur Sanchi were identified for organic acids richness which can be promoted for commercial cultivation. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s13205-023-03907-2.

Rh(III)-Catalyzed C7-Alkylation of Isatogens with Malonic Acid Diazoesters.[Pubmed:38334453]

J Org Chem. 2024 Mar 1;89(5):2984-2995.

Rh(III)-catalyzed C7-alkylation of isatogens (indolin-3-one N-oxides) with Malonic acid diazoesters has been developed. This strategy utilizes oxygen anion on the N-oxide group of isatogens as a directing group and successfully achieves the synthesis of a series of C7-alkylated isatogens with moderate to good yields (48-86% yields). Moreover, the N-oxides of isatogens can not only serve as the simple directing group for C7-H bond cleavage but also be deoxidized for easy removal.

The curious case of proton migration under pressure in the malonic acid and 4,4'-bipyridine cocrystal.[Pubmed:38275161]

IUCrJ. 2024 Mar 1;11(Pt 2):168-181.

In the search for new active pharmaceutical ingredients, the precise control of the chemistry of cocrystals becomes essential. One crucial step within this chemistry is proton migration between cocrystal coformers to form a salt, usually anticipated by the empirical DeltapK(a) rule. Due to the effective role it plays in modifying intermolecular distances and interactions, pressure adds a new dimension to the DeltapK(a) rule. Still, this variable has been scarcely applied to induce proton-transfer reactions within these systems. In our study, high-pressure X-ray diffraction and Raman spectroscopy experiments, supported by DFT calculations, reveal modifications to the protonation states of the 4,4'-bipyridine (BIPY) and Malonic acid (MA) cocrystal (BIPYMA) that allow the conversion of the cocrystal phase into ionic salt polymorphs. On compression, neutral BIPYMA and monoprotonated (BIPYH(+)MA(-)) species coexist up to 3.1 GPa, where a phase transition to a structure of P2(1)/c symmetry occurs, induced by a double proton-transfer reaction forming BIPYH(2)(2+)MA(2-). The low-pressure C2/c phase is recovered at 2.4 GPa on decompression, leading to a 0.7 GPa hysteresis pressure range. This is one of a few studies on proton transfer in multicomponent crystals that shows how susceptible the interconversion between differently charged species is to even slight pressure changes, and how the proton transfer can be a triggering factor leading to changes in the crystal symmetry. These new data, coupled with information from previous reports on proton-transfer reactions between coformers, extend the applicability of the DeltapK(a) rule incorporating the pressure required to induce salt formation.

A mesoionic carbene stabilized nickel(II) hydroxide complex: a facile precursor for C-H activation chemistry.[Pubmed:38226674]

Dalton Trans. 2024 Feb 6;53(6):2749-2761.

We report the synthesis of a new nickel(II) hydroxide complex 2 supported by a rigid, tridentate triazolylidene-carbazolid ligand. The complex can be accessed in high yields following a simple and stepwise extraction protocol using dichloromethane and aqueous ammonium chloride followed by aqeous sodium hydroxide solution. We found that complex 2 is highly basic, undergoing various deprotonation/desilylation reactions with E-H and C-H acidic and silylated compounds. In this context we synthesized a variety of novel, functionalized nickel(II) complexes with trimethylsilylolate (3), trityl sulfide (4), tosyl amide (5), azido (6), pyridine (7), acetylide (8, 9), fluoroarene (10 & 11) and enolate (12) ligands. We furthermore found that 2 reacts with Malonic acid dimethyl ester in a knoevennagel-type condensation reaction, giving access to a new enolate ligand in complex 13, consisting of two Malonic acid units. Furthermore, complex 2 reacts with acetonitrile to form the cyanido complex 14. The formation of complexes 13 and 14 is particularly interesting, as they underline the potential of complex 2 in both C-C bond formation and cleavage reactions.