33 results about "Tetramethyl pyrazine" patented technology

The invention relates to the technical field of microorganisms and particularly discloses bacillus velezensis for producing tetramethylpyrazine and application of the bacillus velezensis, the preservation number of the strain is CCTCC NO: M20232058, and the bacillus velezensis is obtained by separating and purifying from high-temperature Daqu of Maotai-flavor liquor in the liquor industry of Jin-brand Maotai Town in Guizhou. The bacillus velezensis disclosed by the invention can produce 1875.4 mg / L of tetramethylpyrazine by performing shake flask fermentation on a liquid culture medium for 7 days, and the tetramethylpyrazine can reach 4810.8 mg / L by optimizing a culture medium formula and culture conditions. The bacillus velezensis is applied to small-scale brewing of Maotai-flavor liquor, the content of tetramethylpyrazine in the Maotai-flavor liquor reaches 34.5 + / -1.4 mg / L and is increased by 325.93% compared with a contrast, and the bacillus velezensis can be used for increasing the content of tetramethylpyrazine in the Maotai-flavor liquor.

The invention belongs to the technical field of microbial fermentation, and particularly relates to a new enterobacter rorrhizae strain as well as a separation and screening method and application thereof. In order to enrich microbial resources for producing pyrazine substances through metabolism in the white spirit industry, an enterobacter rorrhizae strain is separated and screened from a mixture of yeast for making hard liquor and fermented grains, and the preservation number is CGMCC No.33262. The strain has good tolerance to pH, salt and alcohol, and can adapt to the growth environment in the white spirit production process; and various pyrazine substances represented by tetramethylpyrazine can be produced. Besides, the strain has strong adaptability to fermented grains, the yield of tetramethylpyrazine is high in a culture medium taking bran, wheat and five grains as the fermented grains, and meanwhile, various flavor substances such as ethyl acetate, ethyl hexanoate, ethyl caprylate, 2, 3-butanediol, guaiacol and 4-vinyl guaiacol can be produced. Therefore, the enterobacter rorrhizae disclosed by the invention can be widely used for brewing white spirit.

The invention relates to the technical field of microbial fermentation and bioengineering, in particular to bacillus licheniformis and application thereof in production of acetoin and tetramethylpyrazine. The bacillus licheniformis with high acetoin yield is screened from a large number of strains. The yield of acetoin after the strain is fermented for 36 hours can reach 98 g / L and is far higher than that of other existing natural screened strains, the liquor yield is increased by 11% when the strain is used for liquor brewing, the content of tetramethylpyrazine in liquor is increased by 57%, and the quality of the liquor is obviously improved.

The present application belongs to the technical field of microbial fermentation, and particularly relates to a strain of Kroppenstedtii ivory color and application thereof. In order to provide more high-temperature-resistant and pyrazine-producing brewing microbial resources, a new strain of Kroppenstedtii ivory color MZ35 is isolated from Maotai-flavor Daqu, and the preservation number is CCTCC NO: M 20252598. The strain can adapt to the solid-state fermentation environment of higher temperature and the pile fermentation environment of Maotai-flavor liquor, and promote the formation of tetramethylpyrazine. After MZ35 is inoculated into the solid-state fermentation system of highland barley or the intensified fermentation system of wine lees, the content of tetramethylpyrazine can be significantly increased. In addition, the strain can also promote the accumulation of acetoin, trimethylpyrazine and other Maotai-flavor related substances or precursor substances. Therefore, the strain has important application value for the pile fermentation of liquor, the flavor regulation of wine lees and the preparation of solid-state fermentation products rich in tetramethylpyrazine.

The invention relates to a preparation method of tetramethylpyrazine, which is characterized in that 3-hydroxy-2-butanone and ammonium acetate are used as raw materials, a potassium hydrogen persulfate compound (Oxone) is used as an oxidizing agent, and 2, 3, 5, 6-tetramethylpyrazine is prepared through reaction. The preparation method has the beneficial effects that the reaction is rapid, the condition is mild, an organic solvent is not needed, and industrial popularization is easy; the color of a reaction system solution in the reaction process is light, and the reaction solution can be used mechanically, so that the green, environment-friendly and safe production and purification processes of the product are realized; the prepared product can be directly obtained in a filtering mode, and the product is high in purity, good in appearance, high in yield and suitable for one-pot production.

The invention discloses a two-time water metering method for improving the flavor of Maotai-flavor liquor. After steaming the grains, supplementing 85-90% of total water demand by using hot water, and spreading and airing to 30-38 DEG C; and preparing secondary measuring water from the compound bacteria liquid and the solvent, and supplementing the rest 10-15% of water. The compound bacteria liquid is prepared by compounding bacillus licheniformis, bacillus subtilis and pichia pastoris. The secondary water measurement is completed after the spreading and airing is finished and before the yeast is added, so that the bacillus is preferentially colonized, the excessive wine production of the yeast is inhibited, and the accumulation of a fragrance precursor is promoted. The implementation result shows that the number of bacillus in the fermented grains is increased, the sensory score of 3-5 rounds of main wine is averagely improved, tetramethylpyrazine is increased, and the process is compatible with the traditional 12987 process and is easy to popularize.

The invention discloses bacillus subtilis for producing tetramethylpyrazine and application of the bacillus subtilis in baijiu, and relates to the field of baijiu brewing and food safety. The preservation number of the bacillus subtilis is CCTCC NO: M20241287, and the bacillus subtilis can be applied to preparation of tetramethylpyrazine and / or fermented products, such as Baijiu, and can remarkably improve the content of tetramethylpyrazine and the content of esters in the Baijiu and reduce the content of methyl mercaptan, so that the quality of the Baijiu is improved, the flavor of the Baijiu is optimized, and the quality of the Baijiu is improved. And a new way is provided for production of tetramethylpyrazine and preparation of high-quality white spirit.

The invention discloses a preparation method of composite roasted peanut essence, which belongs to the technical field of essence, and comprises the following steps: preheating peanut oil and caprylic / capric triglyceride; the preparation method comprises the following steps: dissolving ethyl maltol, vanillin, methyl cyclopentenolone, 2, 3, 5-trimethylpyrazine and 2-acetylpyrazine; vanillin propylene glycol acetal, isovaleraldehyde propylene glycol acetal, triethyl citrate, delta-decalactone, delta-dodecalactone and 5-hydroxyethyl-4-methylthiazole are fused to obtain a mixture; dispersing the roasted peanut extract; 2, 3-dimethylpyrazine, 2-methoxyl-5-methylpyrazine and 4-methylthiazole are fused, and then the mixture is subjected to a reaction; the preparation method comprises the following steps: fusing cocaal, dimethyl sulfide, 2-ethyl-3, 5, 6-dimethylpyrazine, 2, 3, 5, 6-tetramethylpyrazine, 2-methylpyrazine, 2-acetylpyridine, 2-methoxy-3. 5. 6-isopropyl pyrazine, 2-methylthio-3-methylpyrazine, isovaleric acid, 1-octylene-3-alcohol, 5-methylfurfural and 3, 4-dimethyl-1, 2-cyclopentanedione; standing is performed; filtering is performed; the fragrance of the roasted peanuts is closer to that of the roasted peanuts which are just taken out of a furnace, and the natural flavor of the roasted peanut essence is increased.

The present application relates to the field of microbial fermentation and bioengineering technology, and particularly relates to bacillus licheniformis and application thereof in acetoin and tetramethylpyrazine production. A bacillus licheniformis with high acetoin yield is screened from a large number of strains. The acetoin yield of the strain can reach 98 g / L after 36 h fermentation, which is much higher than that of other natural screening strains, and the liquor yield is increased by 11% and the content of tetramethylpyrazine in the liquor is increased by 57% when the strain is used for liquor brewing, which obviously improves the quality of the liquor.

The invention discloses a method for regulating and controlling the content of flavor components in the storage and aging process of Baijiu, and belongs to the technical field of Baijiu. The method for regulating and controlling the content of flavor components in the white spirit storage and aging process comprises the following steps: (1) uniformly mixing a catalyst and argil, adding water, mixing, molding and firing to obtain a catalytic promoter; wherein the catalyst is selected from one or more of Fe2O3 (at) SiO2-Al2O3, CuO (at) SiO2-Al2O3 and Pt-Pb (at) SiO2-Al2O3, and the catalyst is selected from one or more of Fe2O3 (at) SiO2-Al2O3; and (2) a catalytic promoter is added in the process of storing the aged white spirit in a pottery jar, and the addition amount of the catalytic promoter is 0-5% of the mass of the white spirit, but not 0. The method disclosed by the invention is beneficial to regulating and controlling the content of flavor components of the Baijiu, and particularly increasing the content of acetovanillin, vanillin, 2-methylpyrazine, 2, 3, 5, 6-tetramethylpyrazine and fenugreek lactone.

The invention relates to the technical field of compound detection, in particular to a detection method of tetramethylpyrazine. The detection method comprises the step of detecting the content of tetramethylpyrazine in a to-be-detected sample by using an ion mobility spectrometry technology, wherein the to-be-detected sample is white spirit or distiller's yeast leach liquor. The detection method is accurate in detection and simple to operate, harmful solvents such as acetonitrile and a chromatographic column do not need to be used, and detection equipment is simplified.

The invention discloses a method for increasing the yield of tetramethylpyrazine, and belongs to the technical field of tetramethylpyrazine preparation. The method for increasing the yield of tetramethylpyrazine comprises the following steps: preparing a fermentation material, adding bacillus for solid-state fermentation, sampling in the solid-state fermentation process, measuring the pH value of the fermentation material, and calculating delta pH; when the delta pH is more than 1, ending the fermentation to obtain a fermentation material containing tetramethylpyrazine; wherein the calculation method of the delta pH is as follows: the pH value of the fermented material after being dried subtracts the pH value of the fermented material before being dried. According to the method for increasing the yield of the tetramethylpyrazine, allogenic materials such as diammonium hydrogen phosphate do not need to be added, the high conversion rate can be achieved at the normal fermentation temperature, the conversion rate from acetoin to the tetramethylpyrazine can be greatly increased through specific heating reaction treatment, the conversion rate is increased to 90% or above, and the yield of the tetramethylpyrazine is increased. The problem of low yield of tetramethylpyrazine in fermentation is effectively solved.

A method for preparing a pork flavour composition, comprising the steps of a) providing a mixture of i) cysteine, and ii) acetoin; and b) reacting said mixture to a flavor composition at a temperature between 30 °C and 55 °C; wherein the flavour composition comprises at least one or more compounds selected from the group consisting of 2,4,5-trimethyl-3-oxazoline, 4,5-dimethyloxazole, 2,4,5-trimethyloxazole, 2- methylthiazole, 4,5-dihydro-2-methylthiazole, trans- or cis-2,4,5-trimethyl-2,5-dihydrothiazole, 2-methyl-3-thiazoline, 2-acetyl-2-methyl-thiazolidine, 2-isopropylthiazolidine, 2,4,5- trimethylthiazole, and tetramethylpyrazine. The flavor composition is a meat flavor composition, in particular a ham and pork flavor composition.

The present invention discloses a genetic engineering strain for producing acetoin, its construction method and application. First, functional genes affecting the stress resistance of Escherichia coli to acetoin are screened and identified, and stress resistance factors are introduced by means of genome genetic modification to improve the tolerance of the strain to the product. Then, by optimizing the copy number of the recombinant plasmid, the expression level of the key genes in the acetoin synthesis pathway is increased to obtain an engineering strain with high synthesis ability and high stress resistance. Then, acetoin is fermented and synthesized using cheap raw materials, and is efficiently converted into tetramethylpyrazine under suitable conditions. Finally, a relatively high-purity tetramethylpyrazine is obtained by converting the decolorized and purified fermentation broth. The process method of the present invention is green and environmentally friendly, and can generate high-value chemicals (R)-acetoin and tetramethylpyrazine, laying an important theoretical and technical foundation for future large-scale industrial production.

The application discloses a preparation method of adamantane nitroketone derivatives and application of the adamantane nitroketone derivatives in ischemic stroke drugs. The adamantane nitroketone derivatives are combined by 2,3,5,6-tetramethylpyrazine and adamantane compounds through nitroketone. The compound not only has strong free radical scavenging capacity, but also integrates the nerve protection function of the adamantane compound.

The invention provides a composition, a biostimulant and application of the biostimulant, and the composition comprises an acetoin aqueous solution, 2, 3-butanediol, tetramethylpyrazine and phenylalanine. According to the composition provided by the embodiment of the invention, efficient and stable targeted color change is realized through triple synergistic effects of signal transduction (acetoin and 2, 3-butanediol)-metabolic regulation (tetramethylpyrazine)-precursor supply (phenylalanine), and meanwhile, the color change effect of the composition is improved. The biostimulant containing the composition and the peptide amino acid liquid can be applied to a plurality of stages such as a post-transplanting stage, a pre-flowering stage, a fruit setting stage, a fruit swelling stage and a color changing stage, so that stable transition and synergistic promotion of crops from vegetative growth to reproductive growth are effectively realized, flower promotion, fruit retention, fruit swelling and color changing are comprehensively realized, furthermore, yield increase and advanced harvesting of the crops can be realized, and the economic benefit of the crops is increased. Meanwhile, the raw materials for improving the sweetness and the vitamin content of the fruits are easy to obtain, the preparation method is simple, industrialization is easy to achieve, and high use value is achieved.

The present invention provides a fermentation desublimation crystallization device for tetramethylpyrazine, comprising a fermentation tank, a spiral coil, a rinsing nozzle, and a stirring mechanism. The spiral coil is located at an upper position inside the fermentation tank, the rinsing nozzle is located inside the fermentation tank and above the spiral coil, and the stirring end of the stirring mechanism is located at a lower position inside the fermentation tank. A pH electrode, a temperature electrode, and a dissolved oxygen electrode for monitoring the state of the fermentation liquid are provided on the side wall of the fermentation tank. A discharge pipe is provided at the bottom end of the fermentation tank, and an inoculation port, an air inlet, and an air outlet are provided at the top end of the fermentation tank. The device of the present invention increases the purification efficiency of tetramethylpyrazine, effectively reduces the impurity content of the purified product, and saves the steps and costs of purifying the fermentation liquid.

The invention belongs to the technical field of microbial fermentation, and particularly relates to a novel bacillus velezensis strain as well as a separation and screening method and application thereof. According to the invention, an enterobacter strain which is different from spores and produces tetramethylpyrazine is excavated. According to the invention, a bacillus velezensis 17 with high yield of tetramethylpyrazine is separated and screened from yeast for making hard liquor and fermented grains, and the bacillus velezensis 17 can grow and ferment in solid culture media such as wheat, mouldy bran, five grains and the like at the same time and can produce various pyrazines. The strain is preserved in the China General Microbiological Culture Collection Center (CGMCC) on September 11, 2025, the preservation number is CGMCC No.35896, the preservation address is Institute of Microbiology, Chinese Academy of Sciences, 3 #, 1 # yard, West Beichen Road, Chaoyang District, Beijing, the postcode is 100101, and the classification name is Bacillus velezensis. The strain provided by the invention can adapt to a plurality of common fermented grain substrates, and shows good industrial adaptability and stability, so that the strain has a wide application prospect in white spirit brewing.

The invention discloses a composition for promoting secretion of extracellular vesicles and application of the composition. The composition for promoting secretion of the extracellular vesicles is prepared from tetramethylpyrazine, salidroside and rapamycin. According to the composition for promoting secretion of the extracellular vesicles, when the mesenchymal stem cells are cultured, the cell state is improved by adjusting components of a culture medium, and on the premise of healthy and normal growth of the cells, serum heterologous exosomes are reduced, the mesenchymal stem cells are promoted to secrete exosomes, and cell replicative aging is prevented.

The invention discloses an electrocatalytic synthesis method of tetramethylpyrazine, which comprises the following steps: dissolving acetoin and ammonium salt in a buffer solution, introducing air, and reacting under the action of 1.2-1.6 V voltage by taking a Cu-based catalyst as a positive electrode and a negative electrode to obtain 2, 3, 5, 6-tetramethylpyrazine. By means of an electro-catalytic synthesis method, cyclization and dehydrogenation reactions are effectively promoted under mild conditions, the wastewater discharge amount is reduced, and construction of an electro-catalytic green synthesis route of 2, 3, 5, 6-tetramethylpyrazine is achieved.

The invention discloses a bacillus cereus strain for producing tetramethylpyrazine and application of the bacillus cereus strain. The name of the bacillus cereus is bacillus cereus A1030, the preservation number of the bacillus cereus is GDMCC No: 66145, and the bacillus cereus is preserved in Guangdong Microbial Culture Collection Center on April 14, 2025. The bacillus cereus has very strong high temperature (50C) resistant and ethanol (20%) resistant growth capability; the bacillus cereus produces protease and amylase, the HC value of the amylase transparent circle is 2.19, and the HC value of the protease transparent circle is 1.7; the liquid state fermentation of the bacillus cereus can produce tetramethylpyrazine, and the content of tetramethylpyrazine is 0.8 g / L.

The application discloses an electrocatalytic synthesis method of tetramethylpyrazine, which comprises the following steps: dissolving ethylidene glycerin and an ammonium salt in a buffer solution, and introducing air; taking a Cu-based catalyst as a positive electrode and a negative electrode, and performing reaction under the action of a voltage of 1.2-1.6 V to obtain 2,3,5,6-tetramethylpyrazine. The electrocatalytic synthesis method effectively promotes the cyclization and dehydrogenation reaction under mild conditions, reduces the wastewater discharge, and realizes the construction of the electrocatalytic green synthesis route of 2,3,5,6-tetramethylpyrazine.

The application provides N-(3,5,6-trimethylpyrazine-2-methylene)-huperzine A and a synthetic method and application thereof. A structural formula is as follows: a preparation method thereof comprises the following steps: (1) carrying out bromination reaction on tetramethylpyrazine to obtain 2-bromomethyl-3,5,6-trimethylpyrazine; (2) carrying out condensation reaction on huperzine A and 2-bromomethyl-3,5,6-trimethylpyrazine to obtain N-(3,5,6-trimethylpyrazine-2-methylene)-huperzine A. The compound not only has acetylcholinesterase inhibition effect, but also can prevent brain nerve tissue aging and cell apoptosis by eliminating ROS and free radicals and resisting oxidative damage, so as to intervene in the development of Alzheimer's disease.

The present application belongs to the technical field of biological fermentation, and particularly relates to a Bacillus sonorensis strain and application thereof. In order to enrich microbial resources for producing 4-vinylguaiacol, 4-vinylphenol and other flavor substances, the present application screens and isolates a Bacillus sonorensis strain from high-temperature Daqu, and the preservation number is CCTCC NO: M 2025364. The strain can utilize wheat at high temperature to metabolize 4-vinylguaiacol, 4-vinylphenol, 3-hydroxy-2-butanone and 2,3,5,6-tetramethylpyrazine and other flavor substances. Therefore, the strain has a wide application prospect in the fields of liquor brewing and food fermentation for improving the yield of 4-vinylguaiacol, 4-vinylphenol, 3-hydroxy-2-butanone and other flavor substances, and can also provide new strain resources for studying phenolic acid decarboxylase from bacteria.

The invention provides screening, mutagenesis and application of a high-yield tetramethylpyrazine strain. The invention relates to a high-yield tetramethylpyrazine strain, which is named as salt-tolerant bacillus (Bacillus halotolans) YB13, the strain is preserved in the China General Microbiological Culture Collection Center on January 12, 2024, and the preservation number is CGMCC No.28161. The tetramethylpyrazine strain has the advantages that the tetramethylpyrazine yield is high, and the tetramethylpyrazine yield is high. According to screening, mutagenesis and application of the high-yield tetramethylpyrazine strain, the high-yield tetramethylpyrazine strain is screened in a liquid culture medium and a solid culture medium through fermentation respectively, the amount of tetramethylpyrazine produced by the salt-tolerant bacillus YB13 in the solid culture medium is remarkably higher than that of other strains, and the salt-tolerant bacillus YB13 is the high-yield tetramethylpyrazine strain. When the strain is applied to white spirit brewing, detection shows that the quality of raw wine added with the salt-tolerant bacillus is higher than that of a control group, and the content of TTMP in the brewing process is also remarkably increased.

The invention belongs to the technical field of biological fermentation, and particularly relates to a bacillus sorola and application thereof. In order to enrich microbial resources for producing flavor substances such as 4-vinyl guaiacol, 4-vinyl phenol and the like, a strain of bacillus sonorrensis is screened and separated from high-temperature yeast for making hard liquor, and the preservation number of the bacillus sonorrensis is CCTCC (China Center for Type Culture Collection) NO: M 2025364. The strain can produce a plurality of flavor substances such as 4-vinyl guaiacol, 4-vinylphenol, 3-hydroxy-2-butanone, 2, 3, 5, 6-tetramethylpyrazine and the like by metabolism of wheat at a high temperature. Therefore, the strain has a wide application prospect in improving the yield of flavor substances such as 4-vinyl guaiacol, 4-vinylphenol and 3-hydroxy-2-butanone in the fields of white spirit brewing and food fermentation, and a new strain resource can be provided for researching phenolic acid decarboxylase derived from bacteria.

The invention relates to a medicine for preventing cerebral arterial thrombosis and a preparation method thereof, and belongs to the technical field of biological medicine, 5, 7, 4 '-trihydroxy flavone and tetramethylpyrazine with the mass ratio of (62-68): (32-38) are sequentially subjected to EPC-Holesterone nanometer coating, primary modification of DSPE-PE G2000-composite peptide containing CREKA peptide and sausage pulp extract peptide, and secondary modification of DSPE-PEG2000-TK to obtain the medicine. According to the invention, 5, 7, 4 '-trihydroxyflavone and tetramethylpyrazine are designed to have a synergistic effect in a scientific ratio, and are matched with the targeting effect of CREKA peptide, the protective effect of sausage pulp extracted peptide and the controlled release and antioxidant effects of DSPE-PEG2000-TK, so that multi-stage synergy of thrombus targeting, gradient controlled release, inflammation inhibition and neuroprotection is realized, the limitation of a traditional single-component medicine is broken through, and the application of the medicine in the preparation of the thrombus targeted medicine is realized. The effectiveness of preventing the nerve injury after the cerebral apoplexy is improved.

The present disclosure relates to a crystalline form of tetramethylpyrazine nitrone, a preparation method thereof, and applications thereof, and provides crystalline form A of tetramethylpyrazine nitrone, which exhibits characteristic diffraction peaks in its XRPD spectrum at 2θ angle positions of 10.60±0.2, 11.03±0.2, 15.31±0.2, 15.55±0.2, 17.14±0.2, 17.93±0.2, and 23.81±0.2. Crystalline form A has a low risk of crystal rearrangement and is highly stable, which is advantageous for stability during preparation manufacturing and storage, effectively ensuring the consistency of the crystalline form content in preparations, and is safe, effective, and allows for quality control. It also has high biological activity and good drug discovery potential, with high bioavailability, rapid onset of effect, and high biological activity.

The invention relates to the technical field of tetramethylpyrazine strain breeding, in particular to a tetramethylpyrazine strain high-throughput breeding device. Comprising a breeding box; a door plate is rotatably mounted on the breeding box, a handle is fixedly connected to the side wall of the door plate, a magnetic strip is embedded in the upper portion of the breeding box, a control panel is mounted on the side wall of the breeding box, ultraviolet lamps which are symmetrically distributed are mounted on the side wall in the breeding box, and a mounting frame is mounted at the bottom in the breeding box. And a mounting groove is formed in the mounting frame. The adding amount of nitrosoguanidine is accurately controlled through the quantitative assembly, the concentration and dosage of a mutagenic agent fed into each adding tank are consistent, the problem that the adding amount of nitrosoguanidine in traditional chemical mutagenesis is difficult to control in a standardized mode is solved, the difference of mutagenesis effects of strains in different batches is effectively avoided, the stability of the positive mutation rate of the strains is guaranteed, and the yield of the strains is increased. And the reliability of chemical mutagenesis is improved.

The invention discloses a rhodium complex-loaded covalent organic framework material as well as a preparation method and application thereof, and belongs to the technical field of photocatalytic materials. The preparation method comprises the following steps: carrying out aldolization reaction on 2, 2 '-bipyridine-5, 5'-dicarboxaldehyde and 2, 4, 6-trimethylpyridine or 2, 3, 5, 6-tetramethylpyrazine in the presence of an inert atmosphere and a cosolvent to obtain a covalent organic framework material crude product; sequentially carrying out washing, Soxhlet extraction, liquid carbon dioxide soaking and supercritical carbon dioxide drying on the covalent organic framework material crude product, then reacting with a rhodium complex [Cp (Rh *) Cl2] 2, and purifying to obtain the covalent organic framework material. The preparation method disclosed by the invention is green and environment-friendly, the problem of collapse of a pore structure caused by purification treatment can be avoided, and the obtained material can reduce carbon dioxide into carbon monoxide at relatively high selectivity and reaction rate when being used as a catalyst for an oxidation-reduction reaction of carbon dioxide and water.