Thermal decomposition pathways of phenylalanine and glutamic acid and the interaction mechanism between the two amino acids and glucose

Chen, Peiao; Gong, Meng; Chen, Yingquan; Zhou, Zhongyue; Liu, Ming; Fang, Yang; Chen, Wei; Yang, Haiping; Chen, Hanping

doi:10.1016/j.fuel.2022.124345

Cited by 20 publications

(6 citation statements)

References 46 publications

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“…Among these 31 possible intermediate products, styrene was considered as a potential and foundational intermediate product, which was generated through decarboxylation and deamidation of phenylalanine at high temperatures, and could be accelerated after adding glucose (Chen et al, 2022). Then, allylbenzene was formed by extending the carbon chain of styrene, and next Nap was generated through further cyclization of aromatic compounds, which might further form Acpy.…”

Section: Resultsmentioning

confidence: 99%

Formation mechanism of polycyclic aromatic hydrocarbons in grilled beef and the mitigative effect of flavonoids

Lv,

Zhang,

Lin

et al. 2024

eFood

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Polycyclic aromatic hydrocarbons (PAHs) are found in many common foods and increase the risk of cancer in humans. This study systematically screened the components that may be related to the formation of PAHs by an excessive addition of 19 amino acids and glucose in the beef patties. Phenylalanine and glucose exhibited the potential as promoters of PAHs, while lysine, aspartic acid, glutamic acid, valine, and methionine exhibited excellent potential as inhibitors of PAHs. Subsequently, a chemical model containing phenylalanine and glucose was established to confirm their roles as precursors of PAHs. The formation mechanism of PAHs showed that naphthalene was first formed as a basic structure, and then, PAHs with more rings were further formed through substitution, addition reactions, or intramolecular cyclization reactions. The mitigative effects of four flavonoids on total PAH contents were in the order: kaempferol > naringenin (better for individual PAH) > myricetin > quercetin (contradictory), which suggested that the antioxidant ability or radical scavenging capacity of flavonoids may be one of the pathways for PAH inhibition.

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Section: Resultsmentioning

confidence: 99%

Formation mechanism of polycyclic aromatic hydrocarbons in grilled beef and the mitigative effect of flavonoids

Lv,

Zhang,

Lin

et al. 2024

eFood

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“…Formulated mechanisms were guided by online measurements of evolved products either offline or via online TG-IR-MS sampling. 19,20 In microwave pyrolysis of certain amino acids (namely, serine, phenylalanine, and glutamic acid), the selective formation of N-compounds displays sensitivity to temperature, whereas the low-temperature window (i.e., 300 °C) favored the generation of amines and cyclic amides through the aforementioned three primary channels. 21 Higher temperatures (400−500 °C) converted amines and amides into nitriles (such as propionitrile) and N-heterocycle (such as pyrrole and indole).…”

Section: Introductionmentioning

confidence: 99%

“…Cracking reactions of N-bounded char produce HCN and HCNO. Formulated mechanisms were guided by online measurements of evolved products either offline or via online TG-IR-MS sampling. , …”

Section: Introductionmentioning

confidence: 99%

Predicting the Decomposition Mechanism of the Serine α-Amino Acid in the Gas Phase and Condensed Media

Al-Kwradi,

Ali,

Altarawneh

2024

ACS Omega

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Comprehending the nitrogen combustion chemistry during the thermal treatment of biomass demands acquiring a detailed mechanism for reaction pathways that dictate the degradation of amino acids. Serine (Ser) is an important α-amino acid that invariably exists in various categories of biomass, most notably algae. Based on density functional theory (DFT) coupled with kinetic modeling, this study presents a mechanistic overview of reactions that govern the fragmentation of the Ser compound in the gas phase as well as in the crystalline form. Thermokinetic parameters are computed for a large set of reactions and involved species. The initial decomposition of Ser is solely controlled by a dehydration channel that leads to the formation of a 2aminoacrylic acid molecule. Decarboxylation and deamination routes are likely to be of negligible importance. The falloff window of the dehydration channel extends until the atmospheric pressure. Bimolecular reactions between two Ser compounds simulate the widely discussed cross-linking reactions that prevail in the condensed medium. It is demonstrated that the formation of the key experimentally observed products (NH 3 , CO 2 , and CO) may originate from direct bond fissions in the melted phase of Ser prior to evaporation. A constructed kinetic model (with 24 reactions) accounts for the primary steps in the degradation of the Ser molecule in the gas phase. These steps include dehydration, decarboxylation, deamination, and others. The kinetic model presents an onset decomposition temperature of 700 K with the complete conversion attained at ∼1090 K. Likewise, the model portrays the temperature-dependent increasing yields of CO 2 and NH 3 . The results presented in this work offer a detailed analysis of the intricate chemical processes involved in nitrogen transformations, specifically in relation to amino acids. Amino acids play a crucial role as the primary nitrogen carriers in biomass, such as microalgae and protein-rich biomass.

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“…Actually, sludge is a mixture of protein and lignocellulose, and the interactions between these components need to be considered; otherwise, the results would differ greatly from the actual situation. 12 However, the model constructed above did not consider the interaction mechanism between the protein and lignocellulose.…”

Section: Introductionmentioning

confidence: 99%

“…Xu et al constructed a sludge model with using Adler’s lignin as the skeleton and studied the nitrogen migration behaviors during combustion; however, the interaction between different components of sludge were not involved. Actually, sludge is a mixture of protein and lignocellulose, and the interactions between these components need to be considered; otherwise, the results would differ greatly from the actual situation . However, the model constructed above did not consider the interaction mechanism between the protein and lignocellulose.…”

Section: Introductionmentioning

confidence: 99%

Interphase Migration of Nitrogen and the Evolution Mechanism of Nitrogen-Containing Functional Groups in Char during Sludge Pyrolysis

Wang,

Zhang,

Hong

et al. 2024

Ind. Eng. Chem. Res.

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Pyrolysis is an effective method to convert organic wastes, such as sludge, into solid fuels, adsorbents, and catalysts. Further, the functional group distribution of the obtained char affects its application performance in subsequent combustion, adsorption, and catalysis field. In this work, the pyrolysis behaviors of sludge at different temperatures were studied by reactive molecular dynamics simulations, and the interphase migration of nitrogen and the evolution mechanism of nitrogen-containing functional groups in char were analyzed. The pyrolysis simulation process included a heating stage (300−2600 K), an early constanttemperature pyrolysis stage (2600 K, 500 ps), and a later constant-temperature pyrolysis stage (2600 K, 2 ns) that removed the influence of gas and tar. In the heating stage, the sludge mainly underwent fragmentation reactions. The pyrrole in the solid phase migrated to the liquid phase and evolved into the amine group, and the gas product mainly consisted of NH 3 . In the early stage of constant-temperature pyrolysis, the main reactions were the polymerization reactions of gas and tar with generating char. During the polymerization process, imine, pyrrole, and pyridine were formed due to cyclization and dehydrogenation. In the later stage of constant-temperature pyrolysis, char underwent a secondary cracking reaction. However, the main nitrogen-containing gas species remained unchanged, although the concentration of HCN increased. In addition, the cyano group in the char was converted into HCN or cyclized into pyridine, and some pyridine further evolved into a nitrogen-containing seven-membered ring and graphite nitrogen.

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Thermal decomposition pathways of phenylalanine and glutamic acid and the interaction mechanism between the two amino acids and glucose

Cited by 20 publications

References 46 publications

Formation mechanism of polycyclic aromatic hydrocarbons in grilled beef and the mitigative effect of flavonoids

Formation mechanism of polycyclic aromatic hydrocarbons in grilled beef and the mitigative effect of flavonoids

Predicting the Decomposition Mechanism of the Serine α-Amino Acid in the Gas Phase and Condensed Media

Interphase Migration of Nitrogen and the Evolution Mechanism of Nitrogen-Containing Functional Groups in Char during Sludge Pyrolysis

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