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Shen X, Chen Y, Omedi JO, Oz E, Oz F, Xiao C, Zhou Y, Chen J, Zeng M. The Effects of Volatile Organic Compounds (VOCs) on the Formation of Heterocyclic Amines (HAs) in Meat Patties, under Different Smoking Temperatures and Durations. Foods 2022; 11:foods11223687. [PMID: 36429279 PMCID: PMC9689661 DOI: 10.3390/foods11223687] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2022] [Revised: 11/08/2022] [Accepted: 11/15/2022] [Indexed: 11/19/2022] Open
Abstract
In this study, UPLC-MS/MS was used to study the effects of smoking duration and temperature on the formation of heterocyclic amines (HAs) in smoke-processed meat patties. Four kinds of free HAs—including F-7,8-DiMeIQx; F-MeAαC; F-Harman and F-Norharman—and six kinds of protein-bound HAs—including B-AαC; B-7,8-DiMeIQx; B-Glu-p-1; B-MeAαC; B-Harman and B-Norharman—were detected and quantified. Among the free HAs, we observed a 23-fold content increase (p < 0.05), from 0−4 h (at 0 h and 4 h they were 4.24 ng·g−1 and 98.33 ng·g−1, respectively), and the content of the free HAs decreased to 78.80 ng·g−1, at 5 h. At the same time, the free HAs content increased from 53.52 ng·g−1, at 50 °C, to 127.16 ng·g−1, at 60 °C, and then decreased continuously. The content of the free HAs was the highest at 60 °C. For the protein-bound HAs, their content was found to generally decrease with the increase in smoking duration and temperature. However, at 5 h, the content of protein-bound HAs slightly increased to 984.2 ng·g−1. Meanwhile, at 90 °C, it increased to 1643.53 ng·g−1. Additionally, a total of 16 volatile organic compounds (VOCs) were found in all of the meat samples, of which 10 VOCs (one acid, three aldehydes and seven phenols) were significantly related to the formation of free HAs. These findings showed that all the different types of HAs were produced under low-temperature processing, which provided scientific insights into the potential generation of HAs during meat smoking processes and could be used as a reference to minimize the risks of cancer related to the consumption of smoked meat products.
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Affiliation(s)
- Xing Shen
- College of Life and Environmental Sciences, Minzu University of China, Beijing 100081, China
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi 214122, China
| | - Yang Chen
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi 214122, China
| | - Jacob Ojobi Omedi
- School of Food Science and Technology, Jiangnan University, Wuxi 214122, China
| | - Emel Oz
- Department of Food Engineering, Faculty of Agriculture, Ataturk University, Erzurum 25240, Turkey
| | - Fatih Oz
- Department of Food Engineering, Faculty of Agriculture, Ataturk University, Erzurum 25240, Turkey
| | - Chunwang Xiao
- College of Life and Environmental Sciences, Minzu University of China, Beijing 100081, China
- Correspondence: (C.X.); (M.Z.)
| | - Yijun Zhou
- College of Life and Environmental Sciences, Minzu University of China, Beijing 100081, China
| | - Jie Chen
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi 214122, China
| | - Maomao Zeng
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi 214122, China
- Correspondence: (C.X.); (M.Z.)
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2
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Du H, Wang Q, Liu Q, Chen Q, Liu H, Xu M, Kong B. Heterocyclic aromatic amine contents and quality characteristics of bacon as influenced by NaCl concentration of brine. J Food Sci 2022; 87:2527-2537. [PMID: 35546277 DOI: 10.1111/1750-3841.16156] [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: 11/26/2021] [Revised: 03/19/2022] [Accepted: 03/28/2022] [Indexed: 11/30/2022]
Abstract
Bacon usually have a high salt content. Excessive intake of salt could cause a harm to human health. Heterocyclic aromatic amines (HAAs) are carcinogenic and mutagenic heterocyclic compounds formed by the reactions of precursor substances at high temperature. This study investigated the influence of different levels of NaCl on the HAA contents and quality characteristics of bacon. Moisture, aw , L* value, b* value, thiobarbituric acid-reactive substance (TBARS), and carbonyl content increased significantly with a decrease in the NaCl concentration of the brine (p < 0.05). There were no significant differences between treatments for a* value, pH, creatine content, sensory redness, bitterness, or off-odor (p > 0.05). Sensory evaluation showed that saltiness in bacon increased significantly with increased NaCl concentrations in brine. The increased NaCl concentrations decreased the total HAAs in fried bacon (p < 0.05). Moreover, the nonpolar HAA contents in bacon were higher than the polar HAA contents; salt concentration mainly affected the nonpolar HAA content. In summary, salt content had a significant influence on the HAA content and the quality characteristic of bacon.
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Affiliation(s)
- Hongzhen Du
- College of Food Science, Northeast Agricultural University, Harbin, China
| | - Qiang Wang
- College of Food Science, Northeast Agricultural University, Harbin, China
| | - Qian Liu
- College of Food Science, Northeast Agricultural University, Harbin, China
| | - Qian Chen
- College of Food Science, Northeast Agricultural University, Harbin, China
| | - Haotian Liu
- College of Food Science, Northeast Agricultural University, Harbin, China
| | - Ming Xu
- Shimadzu Co., Ltd, Shenyang, China
| | - Baohua Kong
- College of Food Science, Northeast Agricultural University, Harbin, China
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3
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Influence of Partial Replacements of NaCl by KCl on Quality Characteristics and the Heterocyclic Aromatic Amine Contents of Bacon. Foods 2022; 11:foods11020143. [PMID: 35053875 PMCID: PMC8774441 DOI: 10.3390/foods11020143] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2021] [Revised: 01/02/2022] [Accepted: 01/04/2022] [Indexed: 11/17/2022] Open
Abstract
The influence of partial replacements of NaCl by KCl (0, 10, 20, and 30%) on the heterocyclic aromatic amine (HAAs) contents and quality characteristics of bacon were investigated. The Na+ content, moisture, aw, pH, L* value, and sensory saltiness decreased and K+ content, a* value, and sensory bitterness increased significantly with increased substituting rates of NaCl by KCl (p < 0.05). There were no significant differences between the control and KCl substitution samples for the b* value, redness, and sensory off-odor (p > 0.05). The creatine content was not affected by the different KCl-substituting rates during the marinating process (p > 0.05), but it diminished in the smoking and frying processes (p < 0.05). The increase in the KCl-substituting rates increased the total heterocyclic aromatic amine (HAA) contents in fried bacon (p < 0.05). Moreover, the nonpolar HAA content in bacon was higher than the polar HAA content (p < 0.05). In summary, the partial replacement of NaCl by KCl increased the total HAA content and led to changes in bacon quality.
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4
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Zhang L, Chen Q, Liu Q, Xia X, Wang Y, Kong B. Effect of different types of smoking materials on the flavor, heterocyclic aromatic amines, and sensory property of smoked chicken drumsticks. Food Chem 2021; 367:130680. [PMID: 34348198 DOI: 10.1016/j.foodchem.2021.130680] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2021] [Revised: 06/25/2021] [Accepted: 07/20/2021] [Indexed: 12/19/2022]
Abstract
This study investigated the effect of different types of smoking materials on the flavor, heterocyclic aromatic amine (HAA) content, and sensory attributes of smoked chicken drumsticks. All smoked samples showed lower pH and L*-value and higher a*-value and b*-value than the control sample (P < 0.05), but no significant differences in water content and water activity (P > 0.05). The samples smoked with sucrose combined with pear-tree woodchips (SP) or green tea leaves (ST) had higher overall acceptability than other samples (P < 0.05). Smoking increased the total HAA content, and the ST sample exhibited the highest total HAA content (P < 0.05). A total of 54 volatile compounds was identified. Overall, SP and ST are suitable for smoked chicken considering the sensory properties, while S and SA are proper for smoked chicken considering the minimization of HAAs, which may provide a theory basis for the production of smoked chicken.
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Affiliation(s)
- Lang Zhang
- College of Food Science, Northeast Agricultural University, Harbin, Heilongjiang 150030, China
| | - Qian Chen
- College of Food Science, Northeast Agricultural University, Harbin, Heilongjiang 150030, China
| | - Qian Liu
- College of Food Science, Northeast Agricultural University, Harbin, Heilongjiang 150030, China
| | - Xiufang Xia
- College of Food Science, Northeast Agricultural University, Harbin, Heilongjiang 150030, China
| | - Yan Wang
- Shimadzu Co. Ltd., Shenyang 110016, China
| | - Baohua Kong
- College of Food Science, Northeast Agricultural University, Harbin, Heilongjiang 150030, China.
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5
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Comparative study on the formation of heterocyclic aromatic amines in different sugar smoking time. Food Control 2021. [DOI: 10.1016/j.foodcont.2021.107905] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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6
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A review on β-carboline alkaloids and their distribution in foodstuffs: A class of potential functional components or not? Food Chem 2021; 348:129067. [PMID: 33548760 DOI: 10.1016/j.foodchem.2021.129067] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2020] [Revised: 12/14/2020] [Accepted: 01/06/2021] [Indexed: 11/23/2022]
Abstract
Pharmacologically active β-carboline alkaloids (βCs) such as harman, norharman and some others are naturally present in plants and occur in many foodstuffs. They have a lot of pharmacological properties, including antitumor, antioxidant, anti-inflammatory and antimicrobial effects, and possess the potential for treating Alzheimer's disease, Parkinson's disease, depression and other central nervous system diseases. Dietary intake is proven to be an important source of βCs. Therefore, it is important to know the amounts of βCs that can be gotten from daily diets. This review summarizes the pharmacological activities, toxicology and formation of βCs, and gives collective information on contents of βCs in different foodstuffs.
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Bellmaine S, Schnellbaecher A, Zimmer A. Reactivity and degradation products of tryptophan in solution and proteins. Free Radic Biol Med 2020; 160:696-718. [PMID: 32911085 DOI: 10.1016/j.freeradbiomed.2020.09.002] [Citation(s) in RCA: 60] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/20/2020] [Revised: 08/06/2020] [Accepted: 09/02/2020] [Indexed: 12/13/2022]
Abstract
Tryptophan is one of the essential mammalian amino acids and is thus a required component in human nutrition, animal feeds, and cell culture media. However, this aromatic amino acid is highly susceptible to oxidation and is known to degrade into multiple products during manufacturing, storage, and processing. Many physical and chemical processes contribute to the degradation of this compound, primarily via oxidation or cleavage of the highly reactive indole ring. The central contributing factors are reactive oxygen species, such as singlet oxygen, hydrogen peroxide, and hydroxyl radicals; light and photosensitizers; metals; and heat. In a multi-component mixture, tryptophan also commonly reacts with carbonyl-containing compounds, leading to a wide variety of products. The purpose of this review is to summarize the current state of knowledge regarding the degradation and interaction products of tryptophan in complex liquid solutions and in proteins. For the purposes of context, a brief summary of the key pathways in tryptophan metabolism will be included, along with common methods and issues in tryptophan manufacturing. The review will focus on the conditions that lead to tryptophan degradation, the products generated in these processes, their known biological effects, and methods which may be applied to stabilize the amino acid.
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Affiliation(s)
- Stephanie Bellmaine
- Merck Life Science, Upstream R&D, Frankfurter Strasse 250, 64293, Darmstadt, Germany
| | - Alisa Schnellbaecher
- Merck Life Science, Upstream R&D, Frankfurter Strasse 250, 64293, Darmstadt, Germany
| | - Aline Zimmer
- Merck Life Science, Upstream R&D, Frankfurter Strasse 250, 64293, Darmstadt, Germany.
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8
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Bousquet P, Hudson A, García-Sevilla JA, Li JX. Imidazoline Receptor System: The Past, the Present, and the Future. Pharmacol Rev 2020; 72:50-79. [PMID: 31819014 DOI: 10.1124/pr.118.016311] [Citation(s) in RCA: 53] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Imidazoline receptors historically referred to a family of nonadrenergic binding sites that recognize compounds with an imidazoline moiety, although this has proven to be an oversimplification. For example, none of the proposed endogenous ligands for imidazoline receptors contain an imidazoline moiety but they are diverse in their chemical structure. Three receptor subtypes (I1, I2, and I3) have been proposed and the understanding of each has seen differing progress over the decades. I1 receptors partially mediate the central hypotensive effects of clonidine-like drugs. Moxonidine and rilmenidine have better therapeutic profiles (fewer side effects) than clonidine as antihypertensive drugs, thought to be due to their higher I1/α 2-adrenoceptor selectivity. Newer I1 receptor agonists such as LNP599 [3-chloro-2-methyl-phenyl)-(4-methyl-4,5-dihydro-3H-pyrrol-2-yl)-amine hydrochloride] have little to no activity on α 2-adrenoceptors and demonstrate promising therapeutic potential for hypertension and metabolic syndrome. I2 receptors associate with several distinct proteins, but the identities of these proteins remain elusive. I2 receptor agonists have demonstrated various centrally mediated effects including antinociception and neuroprotection. A new I2 receptor agonist, CR4056 [2-phenyl-6-(1H-imidazol-1yl) quinazoline], demonstrated clear analgesic activity in a recently completed phase II clinical trial and holds great promise as a novel I2 receptor-based first-in-class nonopioid analgesic. The understanding of I3 receptors is relatively limited. Existing data suggest that I3 receptors may represent a binding site at the Kir6.2-subtype ATP-sensitive potassium channels in pancreatic β-cells and may be involved in insulin secretion. Despite the elusive nature of their molecular identities, recent progress on drug discovery targeting imidazoline receptors (I1 and I2) demonstrates the exciting potential of these compounds to elicit neuroprotection and to treat various disorders such as hypertension, metabolic syndrome, and chronic pain.
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Affiliation(s)
- Pascal Bousquet
- Faculty of Medicine, University of Strasbourg, Strasbourg, France (P.B.); Department of Pharmacology, University of Alberta, Edmonton, Alberta, Canada (A.H.); Laboratory of Neuropharmacology, University Research Institute on Health Sciences, University of the Balearic Islands, Palma de Malllorca, Spain (J.A.G.-S.); and Department of Pharmacology and Toxicology, University at Buffalo, Buffalo, New York (J.-X.L.)
| | - Alan Hudson
- Faculty of Medicine, University of Strasbourg, Strasbourg, France (P.B.); Department of Pharmacology, University of Alberta, Edmonton, Alberta, Canada (A.H.); Laboratory of Neuropharmacology, University Research Institute on Health Sciences, University of the Balearic Islands, Palma de Malllorca, Spain (J.A.G.-S.); and Department of Pharmacology and Toxicology, University at Buffalo, Buffalo, New York (J.-X.L.)
| | - Jesús A García-Sevilla
- Faculty of Medicine, University of Strasbourg, Strasbourg, France (P.B.); Department of Pharmacology, University of Alberta, Edmonton, Alberta, Canada (A.H.); Laboratory of Neuropharmacology, University Research Institute on Health Sciences, University of the Balearic Islands, Palma de Malllorca, Spain (J.A.G.-S.); and Department of Pharmacology and Toxicology, University at Buffalo, Buffalo, New York (J.-X.L.)
| | - Jun-Xu Li
- Faculty of Medicine, University of Strasbourg, Strasbourg, France (P.B.); Department of Pharmacology, University of Alberta, Edmonton, Alberta, Canada (A.H.); Laboratory of Neuropharmacology, University Research Institute on Health Sciences, University of the Balearic Islands, Palma de Malllorca, Spain (J.A.G.-S.); and Department of Pharmacology and Toxicology, University at Buffalo, Buffalo, New York (J.-X.L.)
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9
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Heterocyclic aromatic amine concentrations and quality characteristics of traditional smoked and roasted poultry products on the northern Chinese market. Food Chem Toxicol 2020; 135:110931. [DOI: 10.1016/j.fct.2019.110931] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2019] [Revised: 10/22/2019] [Accepted: 10/28/2019] [Indexed: 11/19/2022]
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10
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Ghassem Zadeh R, Yaylayan V. Indole: A Promising Scavenging Agent for Methylglyoxal and Related Carbonyls in Tryptophan Containing Maillard Model Systems. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2019; 67:6359-6365. [PMID: 31088047 DOI: 10.1021/acs.jafc.9b02286] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
In situ generation of efficient carbonyl trapping agents from amino acids during food processing can be considered a useful approach to control the accumulation of harmful Maillard reaction products in food. Tryptophan is one such amino acid that can be used to generate carbonyl trapping agents. Indole, the main thermal degradation product of tryptophan, is known to react with simple aldehydes through electrophilic aromatic substitution type reactions mainly at carbon positions 2 and 3 in addition to the ring nitrogen. The ability of indole to scavenge three moles of reactive aldehydes per mole of indole such as formaldehyde, methylglyoxal, and phenylacetaldehyde was investigated using model systems containing tryptophan or indole. The model systems were either (a) heated in an aqueous solution in stainless steel reactors at specified time and temperatures and analyzed by qTOF-MS/MS or (b) directly pyrolyzed and analyzed by GC/MS using isotope labeling technique. Unlike the other aldehydes, the initial alcohol formed with phenylacetaldehyde was able to dehydrate and form an stable conjugated system with the indole. In general, indole was able to capture three moles of paraformaldehyde, three moles of methylglyoxal and three moles of phenylacetaldehyde and suppress the formation of 2-amino-1-methyl-6-phenylimidazo(4,5-b)pyridine (PhIP) generated in a model system.
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Affiliation(s)
- Raheleh Ghassem Zadeh
- Department of Food Science and Agricultural Chemistry , McGill University , Lakeshore , Ste. Anne de Bellevue , 21111 Quebec , Canada
| | - Varoujan Yaylayan
- Department of Food Science and Agricultural Chemistry , McGill University , Lakeshore , Ste. Anne de Bellevue , 21111 Quebec , Canada
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11
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Effects of smoking or baking procedures during sausage processing on the formation of heterocyclic amines measured using UPLC-MS/MS. Food Chem 2019; 276:195-201. [DOI: 10.1016/j.foodchem.2018.09.160] [Citation(s) in RCA: 43] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2018] [Revised: 09/25/2018] [Accepted: 09/25/2018] [Indexed: 01/04/2023]
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12
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Gandhi NN, Barrett-Wilt G, Steele JL, Rankin SA. Lactobacillus casei expressing methylglyoxal synthase causes browning and heterocyclic amine formation in Parmesan cheese extract. J Dairy Sci 2018; 102:100-112. [PMID: 30415846 DOI: 10.3168/jds.2018-15042] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2018] [Accepted: 09/10/2018] [Indexed: 11/19/2022]
Abstract
Undesired browning of Parmesan cheese can occur during the latter period of ripening and cold storage despite the relative absence of reducing sugars and high temperatures typically associated with Maillard browning. Highly reactive α-dicarbonyls such as methylglyoxal (MG) are products and accelerants of Maillard browning chemistry and can result from the microbial metabolism of sugars and AA by lactic acid bacteria. We demonstrate the effects of microbially produced MG in a model Parmesan cheese extract using a strain of Lactobacillus casei 12A engineered for inducible overexpression of MG synthase (mgsA) from Thermoanaerobacterium thermosaccharolyticum HG-8. Maximum induction of plasmid-born mgsA led to 1.6 mM MG formation in Parmesan cheese extract and its distinct discoloration. The accumulation of heterocyclic amines including β-carboline derivatives arising from mgsA expression were determined by mass spectrometry. Potential MG-contributing reaction mechanisms for the formation of heterocyclic amines are proposed. These findings implicate nonstarter lactic acid bacteria may cause browning and influence nutritional aspects of Parmesan by enzymatic conversion of triosephosphates to MG. Moreover, these findings indicate that the microbial production of MG can lead to the formation of late-stage Maillard reaction products such as melanoidin and β-carbolines, effectively circumventing the thermal requirement of the early- and intermediate- stage Maillard reaction. Therefore, the identification and control of offending microbiota may prevent late-stage browning of Parmesan. The gene mgsA may serve as a genetic biomarker for cheeses with a propensity to undergo MG-mediated browning.
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Affiliation(s)
- N N Gandhi
- Department of Food Science, Madison 53706
| | - G Barrett-Wilt
- Biotechnology Center, University of Wisconsin, Madison 53706
| | - J L Steele
- Department of Food Science, Madison 53706
| | - S A Rankin
- Department of Food Science, Madison 53706.
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13
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Hong C, Yang P, Li S, Guo Y, Wang D, Wang J. In Vitro/In Vivo Metabolism of Ginsenoside Rg5 in Rat Using Ultra-Performance Liquid Chromatography/Quadrupole-Time-of-Flight Mass Spectrometry. Molecules 2018; 23:E2113. [PMID: 30135411 PMCID: PMC6225384 DOI: 10.3390/molecules23092113] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2018] [Revised: 08/02/2018] [Accepted: 08/05/2018] [Indexed: 12/20/2022] Open
Abstract
Background: Ginsenoside Rg5 has been proved to have a wide range of pharmacological activities. However, the in vitro and in vivo metabolism pathways of ginsenosides are still unclear, which impedes the understanding of their in vivo fate. In this paper, the possible metabolic process of Rg5 was studied and the metabolites are identified. Methods: Samples from rat liver microsomes (RLMs) in vitro and from rat urine, plasma and feces in vivo were collected for analysis after oral administration of Rg5. A rapid analysis technique using ultra-performance liquid chromatography (UPLC)/quadrupole-time-of-flight mass spectrometry (QTOF-MS) was applied for detecting metabolites of Rg5 both in vitro and in vivo. Results: A feasible metabolic pathway was proposed and described for ginsenoside Rg5. A total of 17 metabolic products were detected in biological samples, including the RLMs (four), rat urine (two), feces (13) and plasma (four). Fifteen of them have never been reported before. Oxidation, deglycosylation, deoxidation, glucuronidation, demethylation and dehydration were found to be the major metabolic reactions of Rg5. Conclusions: The present study utilized a reliable and quick analytical tool to explore the metabolism of Rg5 in rats and provided significant insights into the understanding of the metabolic pathways of Rg5 in vitro and in vivo. The results could be used to not only evaluate the efficacy and safety of Rg5, but also identify potential active drug candidates from the metabolites.
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Affiliation(s)
- Chao Hong
- Department of Pharmaceutics, School of Pharmacy, Fudan University & Key Laboratory of Smart Drug Delivery, Ministry of Education, Shanghai 201203, China.
| | - Ping Yang
- Instrumental Analysis Center, School of Pharmacy, Fudan University, Shanghai 201203, China.
| | - Shuping Li
- The MOE Key Laboratory for Standardization of Chinese Medicines and The SATCM Key Laboratory for New Resources and Quality Evaluation of Chinese Medicines, Institute of Chinese Materia Medica, Shanghai University of Traditional Chinese Medicine, Shanghai 201210, China.
| | - Yizhen Guo
- Department of Pharmaceutics, School of Pharmacy, Fudan University & Key Laboratory of Smart Drug Delivery, Ministry of Education, Shanghai 201203, China.
| | - Dan Wang
- Department of Pharmaceutics, School of Pharmacy, Fudan University & Key Laboratory of Smart Drug Delivery, Ministry of Education, Shanghai 201203, China.
| | - Jianxin Wang
- Department of Pharmaceutics, School of Pharmacy, Fudan University & Key Laboratory of Smart Drug Delivery, Ministry of Education, Shanghai 201203, China.
- Institute of Materia Medica, Academy of Integrated Chinese and Western Medicine, Fudan University, Shanghai 200040, China.
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14
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Herraiz T, Galisteo J. Nitrosative deamination of 2'-deoxyguanosine and DNA by nitrite, and antinitrosating activity of β-carboline alkaloids and antioxidants. Food Chem Toxicol 2017; 112:282-289. [PMID: 29277703 DOI: 10.1016/j.fct.2017.12.042] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2017] [Revised: 12/20/2017] [Accepted: 12/21/2017] [Indexed: 02/01/2023]
Abstract
Endogenous and dietary nitrite produces reactive nitrogen species (RNS) that react with DNA causing mutations. The nitrosation of 2'-deoxyguanosine (dGuo) and DNA with nitrite was studied under different conditions, and the reaction and degradation products identified and analysed by HPLC-DAD-MS. Nitrosative deamination of dGuo produced xanthine along with 2'-deoxyxanthosine whereas DNA afforded xanthine. Formation of xanthine increased with nitrite concentration and in low pH such as that of stomach. Xanthine was measured as a marker of nitrosation of dGuo and DNA, and it was subsequently used to study the antinitrosating activity of β-carboline alkaloids, and selected antioxidants. Food-occurring tetrahydro-β-carbolines (THβCs) decreased nitrosative deamination of dGuo and DNA under conditions simulating the stomach. Antinitrosating activity was also evidenced for flavonoids (catechin, quercetin) and indole (melatonin) antioxidants. Among THβCs the most active antinitrosating compounds were 1,2,3,4-tetrahydro-β-carboline-3-carboxylic acids (THβC-3-COOHs) that reacted with nitrite to give N-nitroso derivatives as main products along with 3,4-dihydro-β-carboline-3-carboxylic acids and aromatic β-carbolines (norharman and harman). Antinitrosating activity of THβCs correlated well with the formation of N-nitroso-THβC-3-COOHs. These N-nitroso derivatives were stable at pH 7 but degraded in acid conditions affording nitrosating species.
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Affiliation(s)
- Tomás Herraiz
- Instituto de Ciencia y Tecnología de Alimentos y Nutrición (ICTAN), Spanish National Research Council (CSIC), Juan de la Cierva 3, 28006, Madrid, Spain.
| | - Juan Galisteo
- Instituto de Ciencia y Tecnología de Alimentos y Nutrición (ICTAN), Spanish National Research Council (CSIC), Juan de la Cierva 3, 28006, Madrid, Spain
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15
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Ábrányi-Balogh P, Dancsó A, Slégel P, Volk B, Milen M. Synthesis of 1′-Aryl-1,3′-bi-β-carbolines and Their Saturated Counterparts. Polycycl Aromat Compd 2016. [DOI: 10.1080/10406638.2016.1173073] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Affiliation(s)
- Péter Ábrányi-Balogh
- Directorate of Drug Substance Development, Egis Pharmaceuticals Plc., Budapest, Hungary
| | - András Dancsó
- Directorate of Drug Substance Development, Egis Pharmaceuticals Plc., Budapest, Hungary
| | - Péter Slégel
- Directorate of Drug Substance Development, Egis Pharmaceuticals Plc., Budapest, Hungary
| | - Balázs Volk
- Directorate of Drug Substance Development, Egis Pharmaceuticals Plc., Budapest, Hungary
| | - Mátyás Milen
- Directorate of Drug Substance Development, Egis Pharmaceuticals Plc., Budapest, Hungary
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Herraiz T. N-methyltetrahydropyridines and pyridinium cations as toxins and comparison with naturally-occurring alkaloids. Food Chem Toxicol 2016; 97:23-39. [DOI: 10.1016/j.fct.2016.08.009] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2016] [Revised: 07/22/2016] [Accepted: 08/05/2016] [Indexed: 02/06/2023]
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17
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Ábrányi-Balogh P, Dancsó A, Frigyes D, Volk B, Keglevich G, Milen M. Convenient synthesis of 1-aryl-9H-β-carboline-3-carbaldehydes and their transformation into dihydropyrimidinone derivatives by Biginelli reaction. Tetrahedron 2014. [DOI: 10.1016/j.tet.2014.06.073] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
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18
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Stanstrup J, Schou SS, Holmer-Jensen J, Hermansen K, Dragsted LO. Whey protein delays gastric emptying and suppresses plasma fatty acids and their metabolites compared to casein, gluten, and fish protein. J Proteome Res 2014; 13:2396-408. [PMID: 24708224 DOI: 10.1021/pr401214w] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Whey protein has been demonstrated to improve fasting lipid and insulin response in overweight and obese individuals. To establish new hypotheses for this effect and to investigate the impact of stomach emptying, we compared plasma profiles after intake of whey isolate (WI), casein, gluten (GLU), and cod (COD). Obese, nondiabetic subjects were included in the randomized, blinded, crossover meal study. Subjects ingested a high fat meal containing one of the four protein sources. Plasma samples were collected at five time points and metabolites analyzed using LC-Q-TOF-MS. In contrast to previous studies, the WI meal caused a decreased rate of gastric emptying compared to the other test meals. The WI meal also caused elevated levels of a number of amino acids, possibly stimulating insulin release leading to reduced plasma glucose. The WI meal also caused decreased levels of a number of fatty acids, while the GLU meal caused elevated levels of a number of unidentified hydroxy fatty acids and dicarboxylic fatty acids. Also reported are a number of markers of fish intake unique to the COD meal.
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Affiliation(s)
- Jan Stanstrup
- Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen , Rolighedsvej 30, DK-1958 Frederiksberg C, Denmark
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19
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Li S, Liu W, Teng L, Cheng X, Wang Z, Wang C. Metabolites identification of harmane in vitro/in vivo in rats by ultra-performance liquid chromatography combined with electrospray ionization quadrupole time-of-flight tandem mass spectrometry. J Pharm Biomed Anal 2014; 92:53-62. [DOI: 10.1016/j.jpba.2014.01.003] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2013] [Revised: 01/02/2014] [Accepted: 01/04/2014] [Indexed: 10/25/2022]
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20
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Coucheney E, Daniell TJ, Chenu C, Nunan N. Gas chromatographic metabolic profiling: A sensitive tool for functional microbial ecology. J Microbiol Methods 2008; 75:491-500. [DOI: 10.1016/j.mimet.2008.07.029] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2008] [Revised: 07/30/2008] [Accepted: 07/30/2008] [Indexed: 11/28/2022]
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21
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A spectroscopic study of the interaction of the fluorescent beta-carboline-3-carboxylic acid N-methylamide with DNA constituents: nucleobases, nucleosides and nucleotides. J Fluoresc 2008; 18:961-72. [PMID: 18470601 DOI: 10.1007/s10895-008-0355-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2007] [Accepted: 02/25/2008] [Indexed: 10/22/2022]
Abstract
Interaction between beta-carboline-3-carboxylic acid N-methylamide, betaCMAM, and nucleobases, nucleosides and nucleotides is studied in the ground state with UV-visible, (1)H NMR and (31)P NMR spectroscopies and in the first excited state, with steady-state and time-resolved fluorescence spectroscopy. Job plots show a predominant 1:1 interaction in both electronic states. Association constants are estimated from changes in the absorption spectra, and show that the strongest interaction is produced with the nucleosides: 2'-deoxyadenosine (dAdo) and thymidine (Thd), and with the mononucleotides: 2'-deoxycytidine 5'- monophosphate (5'-dCMP) and uridine 5'- monophosphate (5'-UMP). These results are corroborated by the upfield shifts of two (1)H NMR resonances of the betaCMAM indole group. The (31)P NMR resonance of nucleotides is shifted downfield, suggesting the presence of electrostatic or hydrogen bond interaction with betaCMAM. In the first electronic singlet excited state, static and dynamic quenching of betaCMAM emission is achieved upon addition of nucleobases, nucleosides and nucleotides. This has been analysed using Stern-Volmer kinetics.
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22
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Herraiz T. Identification and occurrence of beta-carboline alkaloids in raisins and inhibition of monoamine oxidase (MAO). JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2007; 55:8534-40. [PMID: 17883257 DOI: 10.1021/jf0719151] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
Monoamine oxidase (MAO) is a mitochondrial enzyme involved in the oxidative catabolism of neurotransmitters and xenobiotic amines, including vasopressor and neurotoxic amines, and a current target for antidepressant and neuroprotective drugs. Raisin extracts and homogenates exhibited reversible in vitro inhibition of MAO isozymes, particularly MAO-A, suggesting the presence of MAO-inhibiting substances. Chromatographic and spectrometric studies showed the occurrence of aromatic beta-carboline alkaloids in raisins, and norharman and harman were identified as the key contributors to MAO inhibition. On average, harman ranged from 6 to 644 ng/g and norharman from 2 to 120 ng/g. Several technological variables appeared to determine the presence of these compounds in raisins. Dark-brown raisins (i.e., sun-dried) contained much higher levels than golden raisins. Tetrahydro-beta-carboline-3-carboxylic acid compounds that are direct precursors of aromatic beta-carbolines were also identified in raisins and appeared in a higher amount, reaching up to 50 microg/g. beta-Carbolines were isolated from raisins and acted as good competitive inhibitors of MAO-A (harman) and MAO-B (norharman) isozymes. These results suggest that beta-carboline alkaloids and perhaps raisins containing a high level of beta-carbolines might exhibit potential activity as MAO inhibitors. The results also show that some raisins can be a source of dietary exposure to bioactive beta-carbolines.
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Affiliation(s)
- Tomás Herraiz
- Spanish Council for Scientific Research, CSIC, Instituto de Fermentaciones Industriales, Juan de la Cierva 3, 28006 Madrid, Spain.
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23
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Saha B, Sharma S, Sawant D, Kundu B. Water as an efficient medium for the synthesis of tetrahydro-β-carbolines via Pictet–Spengler reactions. Tetrahedron Lett 2007. [DOI: 10.1016/j.tetlet.2006.12.112] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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24
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Zhou L, Hopkins AA, Huhman DV, Sumner LW. Efficient and sensitive method for quantitative analysis of alkaloids in hardinggrass (Phalaris aquatica L.). JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2006; 54:9287-91. [PMID: 17147408 DOI: 10.1021/jf061819k] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
An efficient high-performance thin-layer chromatography (HPTLC) method for the analysis of alkaloids in hardinggrass (Phalaris aquatica L.) was developed. The method employed HPTLC glass plates precoated with silica gel 60F-254 as the stationary phase. The solvent system consisted of ethyl acetate/chloroform/7 N NH4OH in methanol (8:2:1, v/v/v). Using unidimensional double-development, bands were well separated for 10 alkaloid standards as well as alkaloids observed in hardinggrass plant extracts. Identities of compounds observed using HPTLC were validated by high-performance liquid chromatography-mass spectrometry (HPLC-MS). Software was used to quantify individual alkaloids in plant samples based on HPTLC retention factors and intensities relative to standards of known concentration. Correlation coefficients of 0.99 were obtained between estimated and actual concentrations for four standards (methyltyramine, hordenine, gramine, and 5-methoxydimethyltryptamine), with linearity in the range of 120-3840 ng/spot. The HPTLC method is repeatable and specific for beta-carboline, tryptamine, gramine, and tyramine type alkaloids in mixed standard and plant extracts. Initial results indicate substantial variation in alkaloid composition among and within hardinggrass populations.
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Affiliation(s)
- Lili Zhou
- Forage Improvement Division and Plant Biology Division, Samuel Roberts Noble Foundation Inc, Ardmore, OK 73401, USA
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25
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Sato E, Kohno M, Niwano Y. Increased level of tetrahydro-beta-carboline derivatives in short-term fermented garlic. PLANT FOODS FOR HUMAN NUTRITION (DORDRECHT, NETHERLANDS) 2006; 61:175-8. [PMID: 17039401 DOI: 10.1007/s11130-006-0028-2] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/07/2006] [Accepted: 08/28/2006] [Indexed: 05/12/2023]
Abstract
In our previous study [1], we found that relatively short-term spontaneous fermentation (40 days at 60-70 degrees C, 85-95% relative humidity) potentiates anti-oxidative properties of garlic, in which scavenging activity against hydrogen peroxide was included. Since tetrahydro-beta-carboline derivatives (THbetaCs) that possess hydrogen peroxide scavenging activity have recently been identified in aged garlic extract, THbetaCs were quantitatively analyzed with liquid chromatography-mass spectrometry (LC-MS). (1R, 3S)-1-Methyl-1,2,3,4-tetrahydro-beta-carboline-3-carboxylic acid (MTCC) and (1S, 3S)-MTCC were found in the fermented garlic extract whereas only trace levels of MTCCs were detected in the row garlic extract. Therefore, it is suggested that relatively short-term fermentation potentiates scavenging activity of garlic against hydrogen peroxide by forming THbetaCs, especially MTCCs.
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Affiliation(s)
- Emiko Sato
- New Industry Creation Hatchery Center, Tohoku University, 6-6-10 Aoba, Aramaki, Aoba-ku, Sendai, 980-8579, Japan
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Ohya T. Identification of 4-methylspinaceamine, a pictet-spengler condensation reaction product of histamine with acetaldehyde, in fermented foods and its metabolite in human urine. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2006; 54:6909-15. [PMID: 16939357 DOI: 10.1021/jf061364z] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
Previous study demonstrated that 4-methylspinaceamine (4-methyl-4,5,6,7-tetrahydro-1H-imidazo[4,5-c]pyridine), a Pictet-Spengler condensation reaction product of histamine with acetaldehyde, is present in human urine. The current study sought to determine whether 4-methylspinaceamine is present in fermented foods; its presence might be expected since both histamine and acetaldehyde are often present in these foods. Soy sauce, fish sauce, cheese, and shao hsing wine (Chinese wine) were found to contain 4-methylspinaceamine. The concentration of 4-methylspinaceamine excreted in human urine was greatly elevated after ingestion of a meal containing soy sauce as a dietary source of 4-methylspinaceamine, demonstrating that the level of 4-methylspinaceamine in human urine was affected by dietary foods. In addition, a metabolite of 4-methylspinaceamine in human urine was investigated. An enhanced peak in the HPLC chromatogram of human urine samples after ingestion of 4-methylspinaceamine-containing foods was observed. A peak at the same retention time was also observed from a human urine sample after administration of 4-methylspinaceamine, suggesting that the peak was due to a metabolite. By comparison with the newly synthesized authentic compound, the metabolite was identified as 1,4-dimethylspinaceamine.
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Affiliation(s)
- Takeshi Ohya
- Faculty of Pharmaceutical Sciences, Josai University, 1-1, Keyakidai, Sakado, Saitama 350-0295, Japan.
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27
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Brandt SD, Mansell D, Freeman S, Fleet IA, Alder JF. Analytical characterisation of the routes by thermolytic decarboxylation from tryptophan to tryptamine using ketone catalysts, resulting in tetrahydro-β-carboline formation. J Pharm Biomed Anal 2006; 41:872-82. [PMID: 16569488 DOI: 10.1016/j.jpba.2006.02.007] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2005] [Revised: 02/01/2006] [Accepted: 02/02/2006] [Indexed: 10/24/2022]
Abstract
N-Alkylated tryptamines have complex psychoactive properties. Routes for clandestine synthesis are described on Internet websites one of which involves the thermolytic decarboxylation of tryptophan to tryptamine as a precursor to psychoactive compounds. High boiling solvents and ketone catalysts have been employed to facilitate the decarboxylation of tryptophan. The present study has revealed that there is formation of tetrahydro-beta-carboline (THBC) derivatives which may originate from reaction with both the solvent and the ketone catalyst. The application of gas chromatography electron- and chemical-ionisation ion trap tandem mass spectrometry (GC-IT-MS-MS), in combination with nuclear magnetic resonance (NMR), led to the isolation and identification of 1,1-disubstituted-tetrahydro-beta-carbolines formed as major impurities in the tryptamine. Confirmation was by synthesis of the THBC derivatives from tryptamine using Pictet-Spengler cyclisation. Under EI-conditions, mass spectral characterisation of the THBCs suggests predominance of alkyl cleavage. These impurities will yield a useful profile for identification of the synthetic pathway and likely reagents employed, particularly a "fingerprint" of the ketone catalyst and an insight into the influence of solvents and catalysts on the formation of by-products.
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Affiliation(s)
- Simon D Brandt
- School of Pharmacy and Chemistry, Liverpool John Moores University, Byrom Street, Liverpool L3 3AF, UK
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28
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Herraiz T, Chaparro C. Analysis of monoamine oxidase enzymatic activity by reversed-phase high performance liquid chromatography and inhibition by beta-carboline alkaloids occurring in foods and plants. J Chromatogr A 2005; 1120:237-43. [PMID: 16386263 DOI: 10.1016/j.chroma.2005.12.009] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2005] [Revised: 11/26/2005] [Accepted: 12/02/2005] [Indexed: 11/23/2022]
Abstract
Monoamine oxidase (MAO) is a flavin adenine dinucleotide (FAD)-containing enzyme located at the outer membranes of mitochondria that catalyzes the oxidative deamination of biogenic and xenobiotic amines. We have used a chromatographic method to measure MAO-enzymatic activity by using kynuramine as a non-selective substrate with its MAO-oxidation product subsequently analyzed by RP-HPLC-DAD and HPLC-mass spectrometry (MS). This method was applied to study the kinetic parameters, inhibition and reaction products of MAO recombinant enzymes in presence of tetrahydro-beta-carboline and beta-carboline alkaloids occurring in foods, plants and mammals. Analysis by HPLC showed that tetrahydro-beta-carbolines or beta-carbolines were not modified by MAO. Several beta-carbolines such as tryptoline (1,2,3,4-tetrahydro-beta-carboline) and 1-methyltryptoline (1-methyl-1,2,3,4-tetrahydro-beta-carboline) were inhibitors of MAO-A; instead their corresponding 6-hydroxy-derivatives (6-hydroxytryptoline and 6-hydroxy-1-methyltryptoline) lacked this activity. Tetrahydro-beta-carboline-3-carboxylic acids were unable to inhibit MAO enzymes. In contrast, their oxidation products, i.e. the fully aromatic beta-carbolines (norharman and harman), acted as good inhibitors of MAO. Two tetrahydro-beta-carbolines (i.e. tryptoline and 1-methyltryptoline) occurring in foods were isolated by solid-phase extraction (SPE) and RP-HPLC from selected samples of sausages and the corresponding extracts exhibited good inhibition properties over MAO-A. These results suggest that beta-carbolines from foods, plants, and mammals may exert inhibitory actions on MAO enzymes.
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Affiliation(s)
- Tomas Herraiz
- Spanish Council for Scientific Research, CSIC, Instituto de Fermentaciones Industriales, Juan de la Cierva 3, 28006 Madrid, Spain.
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29
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Parker CA, Anderson NJ, Robinson ESJ, Price R, Tyacke RJ, Husbands SM, Dillon MP, Eglen RM, Hudson AL, Nutt DJ, Crump MP, Crosby J. Harmane and harmalan are bioactive components of classical clonidine-displacing substance. Biochemistry 2005; 43:16385-92. [PMID: 15610033 DOI: 10.1021/bi048584v] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Elucidation of the structure of the endogenous ligand(s) for imidazoline binding sites, clonidine-displacing substance (CDS), has been a major goal for many years. Crude CDS from bovine lung was purified by reverse-phase high-pressure liquid chromatography. Electrospray mass spectrometry (ESMS) and nuclear magnetic resonance ((1)H NMR) analysis revealed the presence of L-tryptophan and 1-carboxy-1-methyltetrahydro-beta-carboline in the active CDS extract. Competition radioligand binding studies, however, failed to show displacement of specific [(3)H]clonidine binding to rat brain membranes for either compound. Further purification of the bovine lung extract allowed the isolation of the beta-carbolines harmane and harmalan as confirmed by ESMS, (1)H NMR, and comparison with synthetic standards. Both compounds exhibited a high (nanomolar) affinity for both type 1 and type 2 imidazoline binding sites, and the synthetic standards were shown to coelute with the active classical CDS extracts. We therefore propose that the beta-carbolines harmane and harmalan represent active components of classical CDS. The identification of these compounds will allow us to establish clear physiological roles for CDS.
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