Discovery of C5H4N2O2

SDS of cas: 98-97-5. About Pyrazine-2-carboxylic acid, If you have any questions, you can contact Stubba, D; Bensinger, D; Steinbacher, J; Proskurjakov, L; Gomez, AS; Schmidt, U; Roth, S; Schmitz, K; Schmidt, B or concate me.

SDS of cas: 98-97-5. I found the field of Pharmacology & Pharmacy very interesting. Saw the article Cell-Based Optimization of Covalent Reversible Ketoamide Inhibitors Bridging the Unprimed to the Primed Site of the Proteasome beta 5 Subunit published in 2019, Reprint Addresses Schmidt, B (corresponding author), Tech Univ Darmstadt, Clemens Schoepf Inst Organ Chem & Biochem, Alarich Weiss Str 4, D-64287 Darmstadt, Germany.. The CAS is 98-97-5. Through research, I have a further understanding and discovery of Pyrazine-2-carboxylic acid.

The ubiquitin-proteasome system (UPS) is an established therapeutic target for approved drugs to treat selected hematologic malignancies. While drug discovery targeting the UPS focuses on irreversibly binding epoxyketones and slowly-reversibly binding boronates, optimization of novel covalent-reversibly binding warheads remains largely unattended. We previously reported alpha-ketoamides to be a promising reversible lead motif, yet the cytotoxic activity required further optimization. This work focuses on the lead optimization of phenoxy-substituted alpha-ketoamides combining the structure-activity relationships from the primed and the non-primed site of the proteasome beta 5 subunit. Our optimization strategy is accompanied by molecular modeling, suggesting occupation of P1 ‘ by a 3-phenoxy group to increase beta 5 inhibition and cytotoxic activity in leukemia cell lines. Key compounds were further profiled for time-dependent inhibition of cellular substrate conversion. Furthermore, the alpha-ketoamide lead structure 27 does not affect escape response behavior in Danio rerio embryos, in contrast to bortezomib, which suggests increased target specificity.

SDS of cas: 98-97-5. About Pyrazine-2-carboxylic acid, If you have any questions, you can contact Stubba, D; Bensinger, D; Steinbacher, J; Proskurjakov, L; Gomez, AS; Schmidt, U; Roth, S; Schmitz, K; Schmidt, B or concate me.

Reference:
Patent; Chevron Research Company; US4732894; (1988); A;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Chemistry Milestones Of Pyrazine-2-carboxylic acid

Welcome to talk about 98-97-5, If you have any questions, you can contact Alcantara, R; Fuentes, P; Antiparra, R; Santos, M; Gilman, RH; Kirwan, DE; Zimic, M; Sheen, P or send Email.. Safety of Pyrazine-2-carboxylic acid

Safety of Pyrazine-2-carboxylic acid. I found the field of Microbiology very interesting. Saw the article MODS-Wayne, a Colorimetric Adaptation of the Microscopic-Observation Drug Susceptibility (MODS) Assay for Detection of Mycobacterium tuberculosis Pyrazinamide Resistance from Sputum Samples published in 2019, Reprint Addresses Sheen, P (corresponding author), Univ Peruana Cayetano Heredia, Lab Bioinformat & Biol Mol, Fac Ciencias & Filosofia, Lima, Peru.. The CAS is 98-97-5. Through research, I have a further understanding and discovery of Pyrazine-2-carboxylic acid.

Although pyrazinamide (PZA) is a key component of first- and second-line tuberculosis treatment regimens, there is no gold standard to determine PZA resistance. Approximately 50% of multidrug-resistant tuberculosis (MDR-TB) and over 90% of extensively drug-resistant tuberculosis (XDR-TB) strains are also PZA resistant. pncA sequencing is the endorsed test to evaluate PZA susceptibility. However, molecular methods have limitations for their wide application. In this study, we standardized and evaluated a new method, MODS-Wayne, to determine PZA resistance. MODS-Wayne is based on the detection of pyrazinoic acid, the hydrolysis product of PZA, directly in the supernatant of sputum cultures by detecting a color change following the addition of 10% ferrous ammonium sulfate. Using a PZA concentration of 800 mu g/ml, sensitivity and specificity were evaluated at three different periods of incubation (reading 1, reading 2, and reading 3) using a composite reference standard (MGIT-PZA, pncA sequencing, and the classic Wayne test). MODS-Wayne was able to detect PZA resistance, with a sensitivity and specificity of 92.7% and 99.3%, respectively, at reading 3. MODS-Wayne had an agreement of 93.8% and a kappa index of 0.79 compared to the classic Wayne test, an agreement of 95.3% and kappa index of 0.86 compared to MGIT-PZA, and an agreement of 96.9% and kappa index of 0.90 compared to pncA sequencing. In conclusion, MODS-Wayne is a simple, fast, accurate, and inexpensive approach to detect PZA resistance, making this an attractive assay especially for low-resource countries, where TB is a major public health problem.

Welcome to talk about 98-97-5, If you have any questions, you can contact Alcantara, R; Fuentes, P; Antiparra, R; Santos, M; Gilman, RH; Kirwan, DE; Zimic, M; Sheen, P or send Email.. Safety of Pyrazine-2-carboxylic acid

Reference:
Patent; Chevron Research Company; US4732894; (1988); A;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

The Best Chemistry compound:98-97-5

SDS of cas: 98-97-5. About Pyrazine-2-carboxylic acid, If you have any questions, you can contact Wang, YT; Wu, YS; Tang, GM or concate me.

SDS of cas: 98-97-5. I found the field of Materials Science; Optics very interesting. Saw the article Controllable luminescent behaviors with pyrazine and benzimidazole groups: Syntheses, crystal structures and properties published in 2019, Reprint Addresses Wang, YT (corresponding author), Qilu Univ Technol, Shandong Acad Sci, Dept Chem Engn, Jinan 250353, Shandong, Peoples R China.. The CAS is 98-97-5. Through research, I have a further understanding and discovery of Pyrazine-2-carboxylic acid.

A set of new salts containing benzimidazole and pyrazine groups, namely, [HPZBI]X-+(-) nH(2)O (X = Cl (n = 1) (1), NO3 (n = 1) (2), ClO4 (n = 0) (3) and H2PO4 (n = 0) (4)) [PZBI = 2-(pyrazin-2-yl)-1H-benzimidazole], were obtained by the reaction of PZBI and a set of inorganic acid, respectively. The emission maxima can be found at 444, 472, 471, 432 and 443 nm for PZBI and its compounds 1-4 in the solid state at room temperature, respectively. Compared with the free PZBI, the emission maxima of compounds 1-4 are obviously blue/red-shifted for 1-4, indicating that the emission maxima are relative to the intermolecular packing distances. Their photoluminescent lifetime and quantum yield are 1.10 ns and 24.5% for 1, 0.99 ns and 26.4% for 2, 0.94 ns and 21.65% for 3, 2.86 ns and 20.57% for 4, respectively. Compounds 1-4 were structurally characterized by X-ray single crystal diffraction, FT-IR, and UV-Vis spectra. Single crystal X-ray diffraction reveals that pi center dot center dot center dot pi packing interactions and a set of hydrogen bonds can be observed. The shortest distances of pi center dot center dot center dot pi stacking interactions are 3.613, 3.534, 3.731 and 3.492 angstrom in compounds 1-4, respectively. Additionally, the thermal stabilities of compounds 1-4 were investigated in detail.

SDS of cas: 98-97-5. About Pyrazine-2-carboxylic acid, If you have any questions, you can contact Wang, YT; Wu, YS; Tang, GM or concate me.

Reference:
Patent; Chevron Research Company; US4732894; (1988); A;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

An overview of features, applications of compound:Pyrazine-2-carboxylic acid

Formula: C5H4N2O2. Welcome to talk about 98-97-5, If you have any questions, you can contact Wang, ZG; Yan, XJ; Liu, HB; Zhang, DL; Liu, W; Xie, CZ; Li, QZ; Xu, JY or send Email.

Formula: C5H4N2O2. I found the field of Materials Science very interesting. Saw the article A novel hydrazide Schiff base self-assembled nanoprobe for selective detection of human serum albumin and its applications in renal disease surveillance published in 2020, Reprint Addresses Xie, CZ; Xu, JY (corresponding author), Tianjin Med Univ, Sch Pharm, Dept Chem Biol, Tianjin 300070, Peoples R China.; Xie, CZ; Xu, JY (corresponding author), Tianjin Med Univ, Sch Pharm, Tianjin Key Lab Technol Enabling Dev Clin Therape, Tianjin 300070, Peoples R China.. The CAS is 98-97-5. Through research, I have a further understanding and discovery of Pyrazine-2-carboxylic acid.

Human serum albumin (HSA) is considered as a biomarker for the early diagnosis of renal disease, therefore identifying and detecting HSA in biological fluids (especially urine) with an easy method is of great importance. Herein, we report a novel hydrazide Schiff base fluorescent probeN ‘-((7-(diethylamino)-2-oxo-2H-chromen-3-yl)methylene)pyrazine-2-carbohydrazide (NPC), which self-assembled into nanoparticles in aqueous solution. Based on disassembly-induced emission and the site-specific recognition mechanism, the binding ofNPCwith HSA resulted in a fluorescence turn-on response. ProbeNPCexhibited superior selectivity and sensitivity toward HSA with a detection limit of 0.59 mg L(-1)in PBS and 0.56 mg L(-1)in the urine sample. The site-binding mechanism ofNPCwith HSA was explored by fluorescence quenching study, Job’s plot analysis, HSA destruction, site marker displacement and molecular docking. Fluorescence imaging of HSA in MCF-7 cells was achieved by using a non-toxicNPCprobe, suggesting thatNPCcould be applied to visualize the level of HSAin vivo. More importantly, further practical applications of probeNPCin human urine samples were achieved with satisfactory results by using a fluorometer or test paper, which could provide extensive application in clinical diagnosis.

Formula: C5H4N2O2. Welcome to talk about 98-97-5, If you have any questions, you can contact Wang, ZG; Yan, XJ; Liu, HB; Zhang, DL; Liu, W; Xie, CZ; Li, QZ; Xu, JY or send Email.

Reference:
Patent; Chevron Research Company; US4732894; (1988); A;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Final Thoughts on Chemistry for C5H4N2O2

COA of Formula: C5H4N2O2. Welcome to talk about 98-97-5, If you have any questions, you can contact Wang, ZG; Yan, XJ; Liu, HB; Zhang, DL; Liu, W; Xie, CZ; Li, QZ; Xu, JY or send Email.

COA of Formula: C5H4N2O2. I found the field of Materials Science very interesting. Saw the article A novel hydrazide Schiff base self-assembled nanoprobe for selective detection of human serum albumin and its applications in renal disease surveillance published in 2020, Reprint Addresses Xie, CZ; Xu, JY (corresponding author), Tianjin Med Univ, Sch Pharm, Dept Chem Biol, Tianjin 300070, Peoples R China.; Xie, CZ; Xu, JY (corresponding author), Tianjin Med Univ, Sch Pharm, Tianjin Key Lab Technol Enabling Dev Clin Therape, Tianjin 300070, Peoples R China.. The CAS is 98-97-5. Through research, I have a further understanding and discovery of Pyrazine-2-carboxylic acid.

Human serum albumin (HSA) is considered as a biomarker for the early diagnosis of renal disease, therefore identifying and detecting HSA in biological fluids (especially urine) with an easy method is of great importance. Herein, we report a novel hydrazide Schiff base fluorescent probeN ‘-((7-(diethylamino)-2-oxo-2H-chromen-3-yl)methylene)pyrazine-2-carbohydrazide (NPC), which self-assembled into nanoparticles in aqueous solution. Based on disassembly-induced emission and the site-specific recognition mechanism, the binding ofNPCwith HSA resulted in a fluorescence turn-on response. ProbeNPCexhibited superior selectivity and sensitivity toward HSA with a detection limit of 0.59 mg L(-1)in PBS and 0.56 mg L(-1)in the urine sample. The site-binding mechanism ofNPCwith HSA was explored by fluorescence quenching study, Job’s plot analysis, HSA destruction, site marker displacement and molecular docking. Fluorescence imaging of HSA in MCF-7 cells was achieved by using a non-toxicNPCprobe, suggesting thatNPCcould be applied to visualize the level of HSAin vivo. More importantly, further practical applications of probeNPCin human urine samples were achieved with satisfactory results by using a fluorometer or test paper, which could provide extensive application in clinical diagnosis.

COA of Formula: C5H4N2O2. Welcome to talk about 98-97-5, If you have any questions, you can contact Wang, ZG; Yan, XJ; Liu, HB; Zhang, DL; Liu, W; Xie, CZ; Li, QZ; Xu, JY or send Email.

Reference:
Patent; Chevron Research Company; US4732894; (1988); A;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

What Kind of Chemistry Facts Are We Going to Learn About 98-97-5

Welcome to talk about 98-97-5, If you have any questions, you can contact Khan, MT; Chinnasamy, S; Cui, ZL; Irfan, M; Wei, DQ or send Email.. Application In Synthesis of Pyrazine-2-carboxylic acid

Application In Synthesis of Pyrazine-2-carboxylic acid. I found the field of Life Sciences & Biomedicine – Other Topics very interesting. Saw the article Mechanistic analysis of A46V, H57Y, and D129N in pyrazinamidase associated with pyrazinamide resistance published in 2020, Reprint Addresses Wei, DQ (corresponding author), Shanghai Jiao Tong Univ, State Key Lab Microbial Metab, Sch Life Sci & Biotechnol, Minist Educ, Shanghai 200240, Peoples R China.; Wei, DQ (corresponding author), Shanghai Jiao Tong Univ, Joint Lab Int Cooperat Metab & Dev Sci, Minist Educ, Shanghai 200240, Peoples R China.; Wei, DQ (corresponding author), Peng Cheng Lab, Vanke Cloud City Phase 1 Bldg 8,Xili St, Shenzhen 518055, Guangdong, Peoples R China.. The CAS is 98-97-5. Through research, I have a further understanding and discovery of Pyrazine-2-carboxylic acid.

Pyrazinamide (PZA) is a component of first-line drugs, active against latent Mycobacterium tuberculosis (MTB) isolates. The prodrug is activated into the active form, pyrazinoic acid (POA) via pncA gene-encoded pyrazinamidase (PZase). Mutations in pncA have been reported, most commonly responsible for PZA-resistance in more than 70% of the resistant cases. In our previous study, we detected many mutations in PZase among PZA-resistance MTB isolates including A46V, H71Y, and D129N. The current study was aimed to investigate the molecular mechanism of PZA-resistance behind mutants (MTs) A46V, H71Y, and D129N in comparison with the wild type (WT) through molecular dynamic (MD) simulation. MTB positive samples were subjected to PZA drug susceptibility testing (DST) against critical concentration (100ug/ml). The resistant samples were subjected to pncA sequencing. Thirty-six various mutations have been observed in the coding region of pncA of PZA-resistant isolates (GenBank accession No. MH461111) including A46V, H71Y, and D129N. The post-simulation analysis revealed a significant variation in MTs structural dynamics as compared to the WT. Root means square deviations (RMSD) and Root means square fluctuation (RMSF) has been found in variation between WT and MTs. Folding effect and pocket volume were altered in MTs when compared with WT. Geometric matching supports the effect of mutation A46V, H71Y, and D129N on PZase structure that may have an insight effect on PZase dynamics, making them vulnerable to convert pro-PZA into active form, POA. In conclusion, the current analyses will provide useful information behind PZA-resistance for better management of drug-resistant TB. (C) 2020 The Author(s). Published by Elsevier B.V. on behalf of King Saud University.

Welcome to talk about 98-97-5, If you have any questions, you can contact Khan, MT; Chinnasamy, S; Cui, ZL; Irfan, M; Wei, DQ or send Email.. Application In Synthesis of Pyrazine-2-carboxylic acid

Reference:
Patent; Chevron Research Company; US4732894; (1988); A;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Simple exploration of 98-97-5

Category: Pyrazines. About Pyrazine-2-carboxylic acid, If you have any questions, you can contact Hu, L; Liu, S; Song, J; Jiang, YT; He, AY; Xu, JX or concate me.

Category: Pyrazines. I found the field of Environmental Sciences & Ecology very interesting. Saw the article Zirconium-Containing Organic-Inorganic Nanohybrid as a Highly Efficient Catalyst for the Selective Synthesis of Biomass-Derived 2,5-Dihydroxymethylfuran in Isopropanol published in 2020, Reprint Addresses Hu, L; Xu, JX (corresponding author), Huaiyin Normal Univ, Jiangsu Collaborat Innovat Ctr Reg Modern Agr & E, Sch Chem & Chem Engn, Jiangsu Key Lab Biomass Based Energy & Enzyme Tec, Huaian 223300, Peoples R China.. The CAS is 98-97-5. Through research, I have a further understanding and discovery of Pyrazine-2-carboxylic acid.

By the simple assembly of zirconium tetrachloride and diethylenetriaminepentaacetic acid (DTPA), a new acid-base bifunctional zirconium-containing organic-inorganic nanohybrid catalyst (Zr-DTPA) was successfully prepared in this work, and then used for the catalytic transfer hydrogenation (CTH) of biomass-derived 5-hydroxymethylfurfural (HMF) into 2,5-dihydroxymethylfuran (DHMF) using isopropanol as the in situ hydrogen donor and reaction solvent. Satisfactorily, 98.7% HMF conversion and 95.2% DHMF yield could be achieved in 4 h at a moderate reaction temperature of 140 degrees C. After systematic studies, this excellent catalytic activity was proved to be mainly ascribed to the synergistic effect of Lewis-acidic sites (Zr4+) and Lewis-basic sites (O2- and N) with higher strengths and contents. Meanwhile, Zr-DTPA could be readily separated by filtration, when it was repeatedly used 5 recycles, its catalytic activity was not obviously changed, demonstrating that Zr-DTPA had good heterogeneity and reusability. More importantly, Zr-DTPA could also be employed to effectively catalyze the CTH of 5-methylfurfural, furfural, levulinic acid, ethyl levulinate and cyclohexanone into the corresponding products with high yields, indicating that it showed a superior universality for the selective hydrogenation of various biomass-derived carbonyl compounds.Graphical Abstract

Category: Pyrazines. About Pyrazine-2-carboxylic acid, If you have any questions, you can contact Hu, L; Liu, S; Song, J; Jiang, YT; He, AY; Xu, JX or concate me.

Reference:
Patent; Chevron Research Company; US4732894; (1988); A;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Final Thoughts on Chemistry for Pyrazine-2-carboxylic acid

Category: Pyrazines. Welcome to talk about 98-97-5, If you have any questions, you can contact Derasp, JS; Barbera, EA; Seguin, NR; Brzezinski, DD; Beauchemin, AM or send Email.

Category: Pyrazines. I found the field of Chemistry very interesting. Saw the article Synthesis of Hydroxamic Acid Derivatives Using Blocked (Masked) O-Isocyanate Precursors published in 2020, Reprint Addresses Beauchemin, AM (corresponding author), Univ Ottawa, Ctr Catalysis Res & Innovat, Dept Chem & Biomol Sci, Ottawa, ON K1N 6N5, Canada.. The CAS is 98-97-5. Through research, I have a further understanding and discovery of Pyrazine-2-carboxylic acid.

Hydroxamic acids are present in a several pharmaceuticals and agrochemicals. Synthetic strategies providing access to hydroxamic acid derivatives remain limited, typically requiring the use of nucleophilic hydroxylamine reagents. Herein, a synthesis of hydroxamates from unactivated carboxylic acids is reported making use of rare blocked (masked) O-substituted isocyanates. The applicability of this transformation was highlighted by targeting the synthesis of vorinostat and belinostat derivatives.

Category: Pyrazines. Welcome to talk about 98-97-5, If you have any questions, you can contact Derasp, JS; Barbera, EA; Seguin, NR; Brzezinski, DD; Beauchemin, AM or send Email.

Reference:
Patent; Chevron Research Company; US4732894; (1988); A;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Search for chemical structures by a sketch :98-97-5

COA of Formula: C5H4N2O2. Bye, fridends, I hope you can learn more about C5H4N2O2, If you have any questions, you can browse other blog as well. See you lster.

COA of Formula: C5H4N2O2. I found the field of Chemistry very interesting. Saw the article Synthesis and catalytic applications of Ru and Ir complexes containing N,O-chelating ligand published in 2020, Reprint Addresses Turkmen, H (corresponding author), Univ Ege, Fac Sci, Dept Chem, TR-35100 Izmir, Turkey.. The CAS is 98-97-5. Through research, I have a further understanding and discovery of Pyrazine-2-carboxylic acid.

A series of monometallic complexes (Ru1-3, Ir-1(-3)) which have N,O-chelating ligand (pyrazine-2carboxylate (1), pyridine-2-carboxylate (2), quinoline carboxylate(3) and bimetallic complexes (Ru-4,Ru-5, Ir-4(,5)) bridged by pyrazine-2,3- dicarboxylate (4) and imidazole-4,5-dicarboxylate(5) were synthesized and characterized by H-1-, C-13 NMR, FT-IR, and elemental analysis. The crystal structure of Ir-2 was determined by X-ray crystallography. The complexes (Ru1-5, Ir1-5) were applied to investigate the electronic and steric effect of ligand in their catalytic activities in transfer hydrogenation and alpha(alpha)-alkylation reaction of ketones with alcohols. The activities of iridium complexes (Ir1-5) were much more efficient than ruthenium complexes (Ru1-5). The highest activity for both reactions was observed for the complex (Ir2 ) with pyridine-2-carboxylate. The Ir hydride species was monitored for both reactions. (C) 2020 Elsevier B.V. All rights reserved.

COA of Formula: C5H4N2O2. Bye, fridends, I hope you can learn more about C5H4N2O2, If you have any questions, you can browse other blog as well. See you lster.

Reference:
Patent; Chevron Research Company; US4732894; (1988); A;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

What kind of challenge would you like to see in a future of compound:Pyrazine-2-carboxylic acid

Quality Control of Pyrazine-2-carboxylic acid. Welcome to talk about 98-97-5, If you have any questions, you can contact Stonelake, TM; Phillips, KA; Otaif, HY; Edwardson, ZC; Horton, PN; Coles, SJ; Beames, JM; Pope, SJA or send Email.

Quality Control of Pyrazine-2-carboxylic acid. I found the field of Chemistry very interesting. Saw the article Spectroscopic and Theoretical Investigation of Color Tuning in Deep-Red Luminescent Iridium(III) Complexes published in 2020, Reprint Addresses Beames, JM; Pope, SJA (corresponding author), Cardiff Univ, Sch Chem, Cardiff CF10 3AT, Wales.. The CAS is 98-97-5. Through research, I have a further understanding and discovery of Pyrazine-2-carboxylic acid.

A series of heteroleptic, neutral iridium(III) complexes of the form [Ir(L)(2)(N boolean AND O)] (where L = cyclometalated 2,3-disubstituted quinoxaline and N boolean AND O = ancillary picolinate or pyrazinoate) are described in terms of their synthesis and spectroscopic properties, with supporting computational analyses providing additional insight into the electronic. properties. The 10 [Ir(L)(2)(N boolean AND O)] complexes were characterized using a range of analytical techniques (including H-1, C-13, and F-19 NMR and IR spectroscopies and mass spectrometry). One of the examples was structurally characterized using X-ray diffraction. The redox properties were determined using cyclic voltammetry, and the electronic properties were investigated using UV-vis, time-resolved luminescence, and transient absorption spectroscopies. The complexes are phosphorescent in the red region of the visible spectrum (lambda(em) = 633-680 nm), with lifetimes typically of hundreds of nanoseconds and quantum yields ca. 5% in aerated chloroform. A combination of spectroscopic and computational analyses suggests that the long-wavelength absorption and emission properties of these complexes are strongly characterized by a combination of spin-forbidden metal-to-ligand charge-transfer and quinoxaline-centered transitions. The emission wavelength in these complexes can thus be controlled in two ways: first, substitution of the cyclometalating quinoxaline ligand can perturb both the highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital levels (LUMO, Cl atoms on the ligand induce the largest bathochromic shift), and second, the choice of the ancillary ligand can influence the HOMO energy (pyrazinoate stabilizes the HOMO, inducing hypsochromic shifts).

Quality Control of Pyrazine-2-carboxylic acid. Welcome to talk about 98-97-5, If you have any questions, you can contact Stonelake, TM; Phillips, KA; Otaif, HY; Edwardson, ZC; Horton, PN; Coles, SJ; Beames, JM; Pope, SJA or send Email.

Reference:
Patent; Chevron Research Company; US4732894; (1988); A;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem