Reactivity of Maillard products with a pyrrole structure

Klein, E.; Ledl, Franz; Bergmüller, Wolfgang; Severin, Theodor

doi:10.1007/bf01185483

Cited by 25 publications

(11 citation statements)

References 9 publications

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“…Preparation of the Reference Compounds. 5-(Hydroxymethyl)-l-propylpyrrole-2-carbaldehyde (10) was obtained according to a method of Klein et al (1992). 2,3-Dihydro-3,5-dihydroxy-6-methyl-4fl-pyran-4-one (3) was synthesized as described by Van den Ouweland and Peer (1970).…”

Section: Methodsmentioning

confidence: 99%

5-Hydroxy-2-methyl-4-(alkylamino)-2H-pyran-3(6H)-one: A New Sugar-Derived Aminoreductone

Knerr¹,

Pischetsrieder²,

Severin³

1994

J. Agric. Food Chem.

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Section: Methodsmentioning

confidence: 99%

5-Hydroxy-2-methyl-4-(alkylamino)-2H-pyran-3(6H)-one: A New Sugar-Derived Aminoreductone

Knerr¹,

Pischetsrieder²,

Severin³

1994

J. Agric. Food Chem.

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“…The c1 positions of the side-chains attached to pyrrole ring carbons in AFGPs are susceptible to nucleophilic attack by thiols (Klein et al, 1992) and by lysine amino groups (J. Farmar and A. Cerami, unpublished data) ( Figure 5), indicating that AFGPs are likely to be able to crosslink proteins. The requirement of two moles of sugar to form the AFGP structure and the fact that AFGPs are minor products in the absence of sulfite as a trapping agent (Farmar et al, 1988) suggest that AFGP crosslinks may be of limited importance in vivo.…”

Section: Alkyl Formyl Glycosyl Pyrrole (Afgp) Crosslinksmentioning

confidence: 99%

Protein Glycation, Diabetes, and Aging

Ulrich¹,

Cerami²

2001

Recent Progress in Hormone Research

732

545

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Biologicalamines react with reducing sugars to form a complex family of rearranged and dehydrated covalent adducts that are often yellow-brown and/or fluorescent and include many crosslinked structures. Food chemists have long studied this process as a source of flavor, color, and texture changes in cooked, processed, and stored foods. During the 1970s and 198Os, it was realized that this process, called the Maillard reaction or advanced glycation, also occurs slowly in vivo. Advanced glycation endproducts (AGES) that form are implicated, causing the complications of diabetes and aging, primarily via adventitious and crosslinking of proteins. Long-lived proteins such as structural collagen and lens crystallins particularly are implicated as pathogenic targets of AGE processes, AGE formation in vascular wall collagen appears to be an especially deleterious event, causing crosslinking of collagen molecules to each other and to circulating proteins. This leads to plaque formation, basement membrane thickening, and loss of vascular elasticity. The chemistry of these later-stage, glycation-derrved crosslinks is still incompletely understood but, based on the hypothesis that AGE formation involves reactive carbonyl groups, the authors introduced the carbonyl reagent aminoguanidine hydrochloride as an inhibitor of AGE formation in vivo in the mid 1980s. Subsequent studies by many researchers have shown the effectiveness of aminoguanidine in slowing or preventing a wide range of complications of diabetes and aging in animals and, recently, in humans. Since, the authors have developed a new class of agents, exemplified by 4,5-dimethyl-3-phenacylthiazolium chloride (DPTC), which can chemically break already-formed AGE protein-protein crosslinks. These agents are based on a new theory of AGE crosslinking that postulates that a-dicarbonyl structures are present in AGE protein-protein crosslinks. In studies in aged animals, DPTC has been shown to be capable of reverting indices of vascular compliance to levels seen in younger animals. Human clinical trials are underway.

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“…12 Moreover, they can also react together via the Maillard reaction 30 to form N-containing cyclic organic compounds such as pyridines and pyrroles. 31 In many of the previous studies, a temperature range of 300− 350 °C was generally claimed as optimum for HTL because of the highest bio-crude yield that exceeds the original lipid content of biomass. 32−34 However, our group recently reported that high-temperature conversion (>300 °C) increases the overall bio-crude yield but mainly contributes to the increase of the asphaltene fraction (polycyclic aromatic compounds), which contains a high concentration of heteroatoms such as N and S. 35 The asphaltene fraction is a low quality fuel and difficult to convert via subsequent catalytic processes.…”

Section: ■ Introductionmentioning

confidence: 99%

“…Crystalline cellulose (polymers of glucose with β-1,4-glycosidic bonds, linear) with strong inter-/intramolecular hydrogen bonding is hydrolyzed at a temperature above 240 °C. , However, starch (polymers of glucose with β-1,4- and α-1,6-glycosidic bonds, branched) with weaker hydrogen bonding is readily hydrolyzed even below 200 °C. , Proteins are reported to be hydrolyzed to amino acids at a temperature above 230 °C. ,, The monosaccharides and amino acids produced by hydrolysis can be further decomposed in similar temperature ranges . Moreover, they can also react together via the Maillard reaction to form N-containing cyclic organic compounds such as pyridines and pyrroles …”

Section: Introductionmentioning

confidence: 99%

Optimum Utilization of Biochemical Components inChlorellasp. KR1 via Subcritical Hydrothermal Liquefaction

Jin

Chang

et al. 2017

ACS Sustainable Chem. Eng.

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Product distributions in bio-crude, aqueous phase, and solid residue were rigorously analyzed during the hydrothermal liquefaction (HTL) of Chlorella sp. KR1 in order to optimize utilization of energy and chemicals. A non-asphaltene (paraffinic) fraction in the bio-crude, which can be readily upgraded to high-quality fuels via a subsequent catalytic process, was mainly produced due to lipid extraction. Above 170 °C, lipid extraction was almost complete, and hence, the non-asphaltene content did not increase further with increasing temperature. Carbohydrates could be extracted, mainly as polysaccharides, in the aqueous phase at mild temperatures (<200 °C). At high temperatures (>200 °C), they decompose and react with proteins via the Maillard reaction to form asphaltene (polycyclic aromatics), which contains large amounts of heteroatoms such as N and S. Although high-temperature carbohydrate conversion could yield more bio-crude with high energy values, it dominantly contributed to formation of the asphaltene fraction, which is difficult to upgrade catalytically. As high-temperature HTL requires a large energy input, the recovery and utilization of intact carbohydrates and proteins at mild temperatures (<200 °C) appears to be more promising. Energy Return on Investment (EROI) analysis also showed that 170 °C is the optimum HTL temperature for maximizing the energy production.

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Reactivity of Maillard products with a pyrrole structure

Cited by 25 publications

References 9 publications

5-Hydroxy-2-methyl-4-(alkylamino)-2H-pyran-3(6H)-one: A New Sugar-Derived Aminoreductone

5-Hydroxy-2-methyl-4-(alkylamino)-2H-pyran-3(6H)-one: A New Sugar-Derived Aminoreductone

Protein Glycation, Diabetes, and Aging

Optimum Utilization of Biochemical Components inChlorellasp. KR1 via Subcritical Hydrothermal Liquefaction

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