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Zamolo F, Wüst M. 3-Alkyl-2-Methoxypyrazines: Overview of Their Occurrence, Biosynthesis and Distribution in Edible Plants. Chembiochem 2023; 24:e202300362. [PMID: 37435783 DOI: 10.1002/cbic.202300362] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2023] [Revised: 06/26/2023] [Accepted: 07/11/2023] [Indexed: 07/13/2023]
Abstract
Pyrazines are ubiquitous in nature - biosynthesized by microorganisms, insects, and plants. Due to their great structural diversity, they own manifold biological functions. Alkyl- and alkoxypyrazines for instance play a key role as semiochemicals, but also as important aroma compounds in foods. Especially 3-alkyl-2-methoxypyrazines (MPs) have been of great research interest. MPs are associated with green and earthy attributes. They are responsible for the distinctive aroma properties of numerous vegetables. Moreover, they have a strong influence on the aroma of wines, in which they are primarily grape-derived. Over the years various methods have been developed and implemented to analyse the distribution of MPs in plants. In addition, the biosynthetic pathway of MPs has always been of particular interest. Different pathways and precursors have been proposed and controversially discussed in the literature. While the identification of genes encoding O-methyltransferases gave important insights into the last step of MP-biosynthesis, earlier biosynthetic steps and precursors remained unknown. It was not until 2022 that in vivo feeding experiments with stable isotope labeled compounds revealed l-leucine and l-serine as important precursors for IBMP. This discovery gave evidence for a metabolic interface between the MP-biosynthesis and photorespiration.
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Affiliation(s)
- Francesca Zamolo
- University of Bonn, Institute of Nutritional and Food Sciences Chair of Food Chemistry, Friedrich-Hirzebruch-Allee 7, 53115, Bonn, Germany
| | - Matthias Wüst
- University of Bonn, Institute of Nutritional and Food Sciences Chair of Food Chemistry, Friedrich-Hirzebruch-Allee 7, 53115, Bonn, Germany
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2
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Fayek NM, Xiao J, Farag MA. A multifunctional study of naturally occurring pyrazines in biological systems; formation mechanisms, metabolism, food applications and functional properties. Crit Rev Food Sci Nutr 2021:1-17. [PMID: 34933625 DOI: 10.1080/10408398.2021.2017260] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Natural pyrazines, mainly methyl- or ethyl-substituted forms, are commonly applied as flavor ingredients in raw and roasted food. Meanwhile alkylpyrazines are used as food preservatives due to their effective antimicrobial action. These natural pyrazines are widely distributed in several biological systems such as plants, animals, and insects; each with respective physiological role. Besides, pyrazines are formed in food via thermal treatment and fermentation. This review presents the most comprehensive overview of pyrazines with correlation to their chemical structures and different applications with emphasis on their food applications. The major part deals with pyrazines generated in thermally treated food, reaction mechanisms highlighting factors and optimum conditions affecting their production. Additionally, the several metabolic reactions mediating for pyrazines metabolism in humans and excretion via the kidney are discussed and on context to their effects. Lastly, a review of the different techniques applied for pyrazines isolation, detection and quantitation is presented. The study provides future considerations and direction of research on this important dietary component and their applications. Pyrazines multifunctional chemistry is of value to the food sector, by presenting the best practices for their production whilst the detrimental effects are minimized.
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Affiliation(s)
- Nesrin M Fayek
- Pharmacognosy Department, College of Pharmacy, Cairo University, Cairo, Egypt
| | - Jianbo Xiao
- International Research Center for Food Nutrition and Safety, Jiangsu University, Zhenjiang, China.,Department of Analytical Chemistry and Food Science, Faculty of Food Science and Technology, University of Vigo, Vigo, Spain.,College of Food Science and Technology, Guangdong Ocean University, Guangdong Provincial Key Laboratory of Aquatic Product Processing and Safety, Guangdong Province Engineering Laboratory for Marine Biological Products, Guangdong Provincial Engineering Technology Research Center of Seafood, Key Laboratory of Advanced Processing of Aquatic Product of Guangdong Higher Education Institution, Zhanjiang, China
| | - Mohamed A Farag
- Pharmacognosy Department, College of Pharmacy, Cairo University, Cairo, Egypt.,Department of Chemistry, School of Sciences & Engineering, The American University in Cairo, New Cairo, Egypt
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3
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Gu N, Liu S, Qiu C, Zhao L, Pei J. Biosynthesis of 3'-O-methylisoorientin from luteolin by selecting O-methylation/C-glycosylation motif. Enzyme Microb Technol 2021; 150:109862. [PMID: 34489021 DOI: 10.1016/j.enzmictec.2021.109862] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2021] [Revised: 06/23/2021] [Accepted: 06/26/2021] [Indexed: 11/26/2022]
Abstract
Glycosylation and methylation of flavonoids are the main types of structural modifications and can endow flavonoids with greater stability, bioactivity, and bioavailability. In this study, five types of O-methyltransferases were screened for producing O-methylated luteolin, and the biosynthesis strategy of 3'-O-methylisoorientin from luteolin was determined. To improve the production of 3'-O-methylluteolin, the S-adenosyl-l-methionine synthesis pathway was reconstructed in the recombinant strain by introducing S-adenosyl-l-methionine synthetase genes. After optimizing the conversion conditions, maximal 3'-O-methylluteolin production reached 641 ± 25 mg/L with a corresponding molar conversion of 76.5 %, which was the highest titer of methylated flavonoids reported to date in Escherichia coli. 3'-O-Methylluteolin (127 mg) was prepared from 250 mL of the broth by silica gel column chromatography and preparative HPLC with a yield of 79.4 %. Subsequently, we used the biocatalytic cascade of Gentiana triflora C-glycosyltransferase (Gt6CGT) and Glycine max sucrose synthase (GmSUS) to biosynthesize 3'-O-methylisoorientin from 3'-O-methylluteolin in vitro. By optimizing the coupled reaction conditions and using the fed-batch operation, maximal 3'-O-methylisoorientin production reached 226 ± 8 mg/L with a corresponding molar conversion of 98 %. Therefore, this study provides an efficient method for the production of novel 3'-O-methylisoorientin and the biosynthesis strategy for methylated C-glycosylation flavonoids by selective O-methylation/C-glycosylation motif on flavonoids.
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Affiliation(s)
- Na Gu
- Jiangsu Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, Nanjing Forestry University, Nanjing, China; College of Chemical Engineering, Nanjing Forestry University, Nanjing, China; Jiangsu Key Lab of Biomass-Based Green Fuels and Chemicals, Nanjing, China
| | - Simin Liu
- Jiangsu Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, Nanjing Forestry University, Nanjing, China; College of Chemical Engineering, Nanjing Forestry University, Nanjing, China; Jiangsu Key Lab of Biomass-Based Green Fuels and Chemicals, Nanjing, China
| | - Cong Qiu
- Jiangsu Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, Nanjing Forestry University, Nanjing, China; College of Chemical Engineering, Nanjing Forestry University, Nanjing, China; Jiangsu Key Lab of Biomass-Based Green Fuels and Chemicals, Nanjing, China
| | - Linguo Zhao
- Jiangsu Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, Nanjing Forestry University, Nanjing, China; College of Chemical Engineering, Nanjing Forestry University, Nanjing, China; Jiangsu Key Lab of Biomass-Based Green Fuels and Chemicals, Nanjing, China.
| | - Jianjun Pei
- Jiangsu Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, Nanjing Forestry University, Nanjing, China; College of Chemical Engineering, Nanjing Forestry University, Nanjing, China; Jiangsu Key Lab of Biomass-Based Green Fuels and Chemicals, Nanjing, China.
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4
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Hisada T, Kitanosono T, Yamashita Y, Kobayashi S. Zeolite Catalysis Enables Efficient Pyrazinone Synthesis in Water. BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN 2021. [DOI: 10.1246/bcsj.20210112] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- Tomoya Hisada
- Department of Chemistry, School of Science, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Taku Kitanosono
- Department of Chemistry, School of Science, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Yasuhiro Yamashita
- Department of Chemistry, School of Science, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Shū Kobayashi
- Department of Chemistry, School of Science, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
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Cain CN, Haughn NJ, Purcell HJ, Marney LC, Synovec RE, Thoumsin CT, Jackels SC, Skogerboe KJ. Analytical Determination of the Severity of Potato Taste Defect in Roasted East African Arabica Coffee. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2021; 69:2253-2261. [PMID: 33566609 DOI: 10.1021/acs.jafc.1c00605] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
The quality of East African coffee beans has been significantly reduced by a flavor defect known as potato taste defect (PTD) due to the presence of 2-isopropyl-3-methoxypyrazine (IPMP) and 2-isobutyl-3-methoxypyrazine (IBMP). Therefore, the aims of this study were to determine the correlation between these methoxypyrazines and the severity of odor attributed to PTD and discover additional analytes that may be correlated with PTD using Fisher ratio analysis, a supervised discovery-based data analysis method. Specialty ground roasted coffees from East Africa were classified as clean (i.e., no off-odor), mild, medium, or strong PTD. For the samples examined, IPMP was found to discriminate between non-defective and defective samples, while IBMP did not do so. Samples affected by PTD exhibited a wide range of IPMP concentration (1.6-529.9 ng/g). Except for one sample, the IPMP concentration in defective samples was greater than the average IPMP concentration in the non-defective samples (2.0 ng/g). Also, an analysis of variance found that IPMP concentrations were significantly different based on the severity of odor attributed to PTD (p < 0.05). Fisher ratio analysis discovered 21 additional analytes whose concentrations were statistically different based on the severity of PTD odor (p < 0.05). Generally, analytes that were positively correlated with odor severity generally had unpleasant sensory descriptions, while analytes typically associated with desirable aromas were found to be negatively correlated with odor severity. These findings not only show that IPMP concentration can differentiate the severity of PTD but also that changes in the volatile analyte profile of coffee beans induced by PTD can contribute to odor severity.
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Affiliation(s)
- Caitlin N Cain
- Department of Chemistry, University of Washington, Box 351700, Seattle, Washington 98195, United States
| | - Noah J Haughn
- Department of Chemistry, Seattle University, 901 12th Avenue, Seattle, Washington 98122, United States
| | - Hayley J Purcell
- Department of Chemistry, Seattle University, 901 12th Avenue, Seattle, Washington 98122, United States
| | - Luke C Marney
- Department of Chemistry, Seattle University, 901 12th Avenue, Seattle, Washington 98122, United States
| | - Robert E Synovec
- Department of Chemistry, University of Washington, Box 351700, Seattle, Washington 98195, United States
| | - Chelsea T Thoumsin
- Coffee Quality Specialist, 6511-101 Meridien Drive, Raleigh, North Carolina 27616, United States
| | - Susan C Jackels
- Department of Chemistry, Seattle University, 901 12th Avenue, Seattle, Washington 98122, United States
| | - Kristen J Skogerboe
- Department of Chemistry, Seattle University, 901 12th Avenue, Seattle, Washington 98122, United States
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Mutarutwa D, Navarini L, Lonzarich V, Crisafulli P, Compagnone D, Pittia P. Determination of 3-Alkyl-2-methoxypyrazines in Green Coffee: A Study To Unravel Their Role on Coffee Quality. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2020; 68:4743-4751. [PMID: 31838839 DOI: 10.1021/acs.jafc.9b07476] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Although a high concentration of some 3-alkyl-2-methoxypyrazines in green coffee has been associated with an off-flavor described as potato taste defect (PTD) or "peasy" defect, affecting the product quality, the natural concentration of these compounds in good quality coffee beans has never been the subject of a detailed study. 3-Isobutyl-2-methoxypyrazine (1), 3-sec-butyl-2-methoxypyrazine (2), 3-isopropyl-2-methoxypyrazine (3) concentrations were determined on a range of selected, good quality green coffees of different botanical species (arabica and robusta) and geographical origin. The presence of the three methoxypirazines was confirmed in all samples; the concentration of compound 1 was significantly higher than those of compounds 3 and 2, showing a geographical-origin-dependent variability. This whole set of experimental data was then used as a reference to ascertain the PTD occurrence in "suspected PTD" and insect-damaged samples. Compound 3 was the main indicator of defectiveness, with a main variability in its concentration in insect-damaged samples, suggesting that the insect-induced damage is not a sufficient condition to induce the off-flavor. The analysis in fresh potatoes, carried out to disclose the origin of the term used to describe the PTD in coffee, showed a very low concentration of 3-alkyl-2-methoxypyrazines. However, the relative prevalence of compound 3 on the total of 3-alkyl-2-methoxypyrazines could be related to the characteristic "potato" flavor frequently evoked to describe the sensory perceived defect in coffee.
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Affiliation(s)
- Delvana Mutarutwa
- Faculty of Bioscience and Technology for Food, Agriculture and Environment, University of Teramo, Via Renato Balzarini 1, 64100 Teramo, Italy
| | - Luciano Navarini
- Aromalab illycaffè S.p.A., Area di Ricerca, Padriciano 99, 34149 Trieste, Italy
- illycaffè S.p.A., Via Flavia 110, 34147 Trieste, Italy
| | - Valentina Lonzarich
- Aromalab illycaffè S.p.A., Area di Ricerca, Padriciano 99, 34149 Trieste, Italy
- illycaffè S.p.A., Via Flavia 110, 34147 Trieste, Italy
| | - Paola Crisafulli
- Aromalab illycaffè S.p.A., Area di Ricerca, Padriciano 99, 34149 Trieste, Italy
- illycaffè S.p.A., Via Flavia 110, 34147 Trieste, Italy
| | - Dario Compagnone
- Faculty of Bioscience and Technology for Food, Agriculture and Environment, University of Teramo, Via Renato Balzarini 1, 64100 Teramo, Italy
| | - Paola Pittia
- Faculty of Bioscience and Technology for Food, Agriculture and Environment, University of Teramo, Via Renato Balzarini 1, 64100 Teramo, Italy
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Zhao X, Ju Y, Wei X, Dong S, Sun X, Fang Y. Significance and Transformation of 3-Alkyl-2-Methoxypyrazines Through Grapes to Wine: Olfactory Properties, Metabolism, Biochemical Regulation, and the HP-MP Cycle. Molecules 2019; 24:E4598. [PMID: 31888183 PMCID: PMC6943733 DOI: 10.3390/molecules24244598] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2019] [Revised: 12/12/2019] [Accepted: 12/13/2019] [Indexed: 11/16/2022] Open
Abstract
3-Alkyl-2-methoxypyrazines (MPs) contribute to the herbaceous flavor characteristics of wine and are generally considered associated with poor-quality wine. To control the MPs in grapes and wine, an accurate understanding of MP metabolism is needed. This review covers factors affecting people in the perception of MPs. Also, the history of O-methyltransferases is revisited, and the present review discusses the MP biosynthesis, degradation, and biochemical regulation. We propose the existence of a cycle between MPs and 3-alkyl-2-hydropyrazines (HPs), which proceeds via O-(de)methylation steps. This cycle governs the MP contents of wines, which make the cycle the key participant in MP regulation by genes, environmental stimuli, and microbes. In conclusion, a comprehensive metabolic pathway on which the HP-MP cycle is centered is proposed after gaining insight into their metabolism and regulation. Some directions for future studies on MPs are also proposed in this paper.
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Affiliation(s)
- Xianfang Zhao
- College of Enology, Heyang Viti-Viniculture Station, Northwest A&F University, Yangling 712100, China; (X.Z.); (Y.J.); (X.W.); (S.D.)
- Life School of Science and Technology, Henan Institute of Science and Technology, Xinxiang 453003, China
| | - Yanlun Ju
- College of Enology, Heyang Viti-Viniculture Station, Northwest A&F University, Yangling 712100, China; (X.Z.); (Y.J.); (X.W.); (S.D.)
| | - Xiaofeng Wei
- College of Enology, Heyang Viti-Viniculture Station, Northwest A&F University, Yangling 712100, China; (X.Z.); (Y.J.); (X.W.); (S.D.)
| | - Shuo Dong
- College of Enology, Heyang Viti-Viniculture Station, Northwest A&F University, Yangling 712100, China; (X.Z.); (Y.J.); (X.W.); (S.D.)
| | - Xiangyu Sun
- College of Enology, Heyang Viti-Viniculture Station, Northwest A&F University, Yangling 712100, China; (X.Z.); (Y.J.); (X.W.); (S.D.)
| | - Yulin Fang
- College of Enology, Heyang Viti-Viniculture Station, Northwest A&F University, Yangling 712100, China; (X.Z.); (Y.J.); (X.W.); (S.D.)
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