Relationship between Structures and Carcinogenicities of Heterocyclic Amines

Semi-empirical molecular orbital calculations were performed on heterocyclic aromatic amines(HCAs). The relationship between the structures and the carcinogenicities can be rationally elucidated by the models based on the metabolism of HCAs and the Di-region theory. The degree of easiness for the formation of Di-region electrophilic centers determines the carcinogenic activity. There is a good linear relationship between the observed carcinogenicities and the PM3 calculated parameters, with r=0.973 and F=29.8>F ** 0.01 .

Effect of pomegranate peel extract on the reduction of heterocyclic amines and quality characteristics of mutton meatballs

Pomegranate peel extract(PPE),rich in phenolic compounds,is an undervalued byproduct derived from processing pomegranates.However,there are very few studies on the inhibitory effect of PPE on harmful substances during meat processing.This study was intended to investigate the influence of different concentrations of PPE(0.50%,1%,and 1.50%)on the generation of heterocyclic amines(HCAs)and some quality attributes in mutton meatballs.All samples with the addition of PPE(0,0.50%,1%,and 1.50%)were fried for different lengths of time(2.5 min and 5 min)at 175±5 C,and the contents of fourteen HCAs,color,thiobarbituric acid reactive substances,and carbonyl values of fried mutton meatballs were evaluated.The results showed that samples fried at 2.5 min had a low HCA content,and the HCA content enhanced signifi-cantly when the frying time was increased from 2.5 to 5 min(P<0.05).In comparison with the control group,PPE could significantly inhibit the generation of total HCAs in fried mutton meatballs(P<0.05),and the total HCAs content decreased with increasing PPE concentration.PPE significantly reduced carbonyl andTBARS values in fried mutton meatballs(P<0.05).Moreover,PPE resulted in a significant increase in a*and b*values as well as a decrease in L*values in fried mutton meatballs(P<0.05).In conclusion,PPE could inhibit the formation of HCAs and improve the quality of mutton meatballs,and could be considered as a natural inhibitor of HCAs in fried meat products.

The role of flavonoids in mitigating food originated heterocyclic aromatic amines that concerns human wellness

Meat products are an important part in our daily diet,providing valuable nutrients for the human body.However,heating processes cause the meat to become more appetizing with changes in texture,appearance,flavor,and chemical properties by the altering of protein structure and other ingredients.As one kind of cooking-induced contaminants,heterocyclic aromatic amines(HAAs)are widely present in protein aceous food products with strong carcinogenic and mutagenic properties.In order to promote the safety of traditional meat products,this review focused on the formation,metabolism,biological monitoring and inhibitory mechanism of HAA.An overview of the formation pathways,hazards,and control methods of HAAs during food processing in recent years was studied,aiming to provide some valuable information for exploring effective methods to inhibit the production of associated hazards during food processing.Systematic selection of different types of flavonoids to explore their effects on the formation of HAAs in an actual barbecue system can provide theoretical reference for effectively controlling the formation of HAAs and reducing their harm to human health.

Processing stage-guided effects of spices on the formation and accumulation of heterocyclic amines in smoked and cooked sausages

Heterocyclic amines (HAs) could be generated though sausage processing.The results showed that garlic,black pepper,chili inhibited the formation of HAs (584.29 ng/g,613.11 ng/g,677.23 ng/g) whereas ginger and Sichuan pepper intensified (965.66 ng/g,916.59 ng/g) compare with control sausage 863.86 ng/g.Furthermore,the study showed that garlic,black pepper,chilli all inhibited the formation of total HAs at stage of raw,drying,baking and steaming and had different inhibitory effect at every stage.Black pepper had the best inhibitory effect across four stages and inhibition rate reached 65%,69%,66%,84% after each stage.Chilli was the only one had inhibitory effect on both free and protein-bound HAs at every stage and inhibition rate about free and protein-bound HAs reached 38% and 76% in finished sausage.Adding certain spices properly during processing would be helpful to obtain fewer HAs in sausage.

Inhibition of Heterocyclic Aromatic Amines in Pork Chops Using Complex Marinades with Natural Antioxidants

Five marinades were developed using natural antioxidants. Based on a consumer test of the appearance, three marinades were chosen for further investigation: an oregano, an acerola and a Dijon marinade, the Dijon marinade containing acerola, sumac and oregano. A barbecue and a sumac marinade were not included in the further study. In a home use test, consumers barbecued pork chops with the three marinades. Most of the consumers preferred the oregano and the Dijon marinade, while the acerola marinade was less liked. After controlled cooking using both direct and indirect heat to a core temperature of 65°C and 80°C, the content of the heterocyclic aromatic amines (HCA) PhiP, MeIQx, DiMeIQx, Harman and Norharman was analysed. All of the marinades reduced the content of MeIQx and DiMeIQx, although only with indirect heat, while PhiP was reduced using both grilling methods. Surprisingly, in particular the content of Harman—and to a lesser extent Norhaman—was very high in the Dijon-marinated chops. The results demonstrated that it was possible to develop well-liked marinades that can reduce the formation of selected HCAs.

An Efficient Synthesis of Heterocyclic Substituted Ureidoalkylphosphonates

A convenient synthesis of various heterocyclic substituted ureidoalkylphosphonic acid diphenyl esters 3 is reported in this paper, alpha-Aminoalkylphosphonic acid diphenyl esters 1 reacted with triphosgene, and then treated with heterocyclic amines gave 3. Small amount of symmetric urylenediphosphonate 4 are isolated as side products.

THE REACTION OF BENZOYL SUBSTITUTED HETEROCYCLIC KETENE AMINALS WITH ARYL AZIDES.A FACILE APPROACH TO SYNTHSIZE 1,5-DIARYL-4-(2-IMIDAZOLINYL)-1,2,3-TRIAZOLES

Heterocyclic ketene aminals 1 react with aryl azides 2 to give the titled compounds 3,and in some cases also with the formation of fused heterocycles 4.

THE RADICAL NUCLEOPHILIC SUBSTITUTION REACTION OF HETEROCYCLIC KETENE AMINALS WITH 2,4-DINITROHALOBENZENES

The anion of heterocyclic ketene aminals reacted with 2,4-dini- tro-halobenzenes to give an arylated product through the radical nucleo- philic substitution confirmed by ESR spectroscopy,ESR-spin trapping techni- que,and depression of the reaction rate by the addition of inhibitor.

Synthesis of O-Glycosides of Heteroatom Aroyl-Substituted Heterocyclic Ketene Aminals

Heteroatom aroyl-substituted heterocyclic ketene aminals 1 reacted with 2,3,4,6-tetra-O-acetyl-α-glucopyranosyl bromide 2 under the catalysis of Hg(CN)2 or CaH2 to give E- or Z-O-glycosides of heterocyclic ketene aminals 3 or 4 in moderate yields.

Critical steps in the production of oil from oilseed to reduce heterocyclic aromatic amines

Contamination by the heterocyclic aromatic amines(HAAs)norharman and harman is one of the risks in vegetable oil production,so oil producers strive to decrease their content in the end products.In this study,the effects of production conditions—specifically,two pretreatment methods(roasting and microwaving),four extraction methods(two pressing and two solvent extraction)and adsorption refining(four absorbents)—of five oils(flaxseed,peanut,rapeseed,sesame,and sunflower seed)were evaluated.The results showed that microwaving as a pretreatment produced significantly fewer HAAs than roasting(P<0.05).After two pretreatments,the HAA content of oils was ranked from high to low as follows:sunflower oil,sesame oil,flaxseed oil,rapeseed oil,and peanut oil.Solvent-extracted oils(9.16–316.73μg/kg)had fewer HAAs than pressed oils(26.61–633.93μg/kg).Using adsorbents reduced HAAs in oils from the initial 21.77–484.22 to 0.31–41.58μg/kg,and the removal rate reached 99.28%.This study provides critical HAA reduction strategies for application in the oil production process to obtain safe final products.

Risk assessment of chemical substances of safety concern generated in processed meats

This manuscript is reviewing the presence of substances of safety concern that may be generated in different types of meat products.Such substances include N-nitrosamines that can be generated under certain conditions when using nitrite as preservative,the polycyclic aromatic hydrocarbons generated as a consequence of particular smoking processes,heterocyclic aromatic amines generated under particular cooking conditions,compounds released from the oxidation of lipids and proteins,Maillard reaction products like acrylamide and carboxymethyl lysine,and amines that can be generated and accumulated in fermented meats.These hazardous compounds,their mechanisms of generation,risks for health and ways of preventing its presence in meat products are briefly described in this review.

Synthesis of 6-chloro and 6-fluoro-4-hydroxyl-2-quinolone and their azo disperse dyes

In this study,6-chloro-4-hydroxy-2-quinolone and 6-flouro-4-hydroxy-2-quinolone were synthesized from corresponding dianilides.These compounds were coupled with some diazotized aromatic amines to give the corresponding azo disperse dyes.The structures of the quinolone derivatives and new azo dyes were confirmed by UV-vis,FT-IR,;H NMR and elemental analysis.

Cation-anionicpalladium Complexes—New Types of Antitumor, Immune Response-modulating and Radioprotective Agents

Here we report results of our investigations of new class of bioactive palladium compounds (AH n ) m [PdCl 4 ], which were discovered as a result of systematic study of correlations between composition, structure and bioactivity of different types of platinum metals coordination compounds. For the first time we demonstrated in vivoa possibility of development of palladium compounds, which exceed cisplatin in antitumor activity and do not show immunosuppressive effects, and palladium compounds with immunostimulating and radioprotective activities. Combinations of cytostatic agents or radiation with palladium complexes lead to significant synergism of their activities and high therapeutic efficiency exceeded an efficiency of their separated use.

Porous boronate affinity monolith for on-line extraction coupled to high-performance liquid chromatography for sensitive analysis of heterocyclic aromatic amines in food samples

A novel on-line solid-phase microextraction–high-performance liquid chromatography（SPME–HPLC）system was developed for the determination of heterocyclic aromatic amines（HAAs） in food samples. A poly（vinylphenylboronic acid-co-ethylene glycol dimethacrylate） polymer monolith was prepared for on-line efficient extraction and large-volume injection was used to increase the sensitivity of detection.The polymermonolith, based on a ternary porogen, was prepared by in situ polymerization of vinylphenylboronic acid（VPBA） and ethylene glycol dimethacrylate（EGDMA） in a fused-silica capillary column. It showed good permeability, high extraction capacity, and high selectivity. The column-tocolumn reproducibility was satisfactory, and the enrichment factors for HAAs were 3746–7414.Conditions influencing the on-line extraction efficiency, including p H of sample solutions, flow rate of extraction and desorption, and desorption volume, were investigated. The proposed method had low limit of detection（0.10–0.15 ng/L） and good linearity. Trace HAAs in roast beef and lamb samples were determined, and the amounts of 2-amino-3-methylimidazo[4,5-f]quinoline, 2-amino-3,4-dimethylimidazo[4,5-f]quinoline, 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline, 2-amino-3,4,8-trimethylimidazo[4,5-f]quinoxaline, and 2-amino-3,4,7,8-tetramethyl-3H-imidazo[4,5-f]quinoxaline in these samples were 0.235–2.08 ng/g. The recoveries for the five HAAs ranged from74.3% to 119%, and the relative standard deviation（RSDs） were less than 8.2%. The results showed that the proposed on-line method was highly sensitive for monitoring HAAs in different food samples.

Effect of woodchip types on heterocyclic aromatic amine formation and quality characteristics of smoked bacon

The impact of different woodchips(beech,oak,pear,and apple)on the contents of heterocyclic aromatic amines(HAAs)and quality characteristics of smoked bacon was investigated.The results indicated that the contents of total HAAs and non-polar HAAs in beech-and oak-smoked bacon were lower than that in pear-and apple-smoked bacon(P<0.05).There were no HAAs detectable in control(non-smoking)sample.The smoking process promoted the formation of free amino acids(FAA)in the smoked bacon.The total contents of FAA in beech-and oak-smoked bacon were higher than these in the pear-and apple-smoked bacons(P<0.05).The beech-smoked bacon had the highest L^(*)-value(P<0.05),and oak-smoked bacon had the lowest thiobarbituric acid-reactive substance(TBARS)value and carbonyl content(P<0.05).Additionally,woodchip types had no significant influence on a^(*)-value,b^(*)-value,moisture content,aw,T_(20),T_(21) and T_(22)(P>0.05).PCA of the HAA contents and quality characteristics could effectively differentiate that were unsmoked and smoked bacon.Therefore,woodchip types had a great influence on HAA contents and quality of smoked bacon.

O-Maltosylation of Heterocyclic Ketene Aminals

The stereoselective synthesis of O-maltosides by reacting benzoyl-substituted heterocyclic ketene aminals 1 or 2 with acetylated maltosyl bromide 3 was investigated. Compounds 1 or 2 reacted with 3 in the presence of mercuric cyanide to give O-maltosides 4 or 5 with E-configuration. While 1 reacted with 3 in the presence of calcium hydride to give O-maltosides 6 with Z-configuration.

A novel and facile synthesis of 2-oxo-1,2-dihydropyridine-fused 1,3-diazaheterocycles via heterocyclic ketene aminals and Konevenagel adducts formed by phthalic anhydride and ethyl cyanacetate

An efficient synthetic pathway to 2-oxo-1,2-dihydropyridine-fused 1,3-diaza heterocycles from heterocyclic ketene aminals,phathalic anhydride and ethyl cyanacetate was established.This protocol involved aza-ene reaction/imine-enamine tautomerization/enamine-ester exchange/ring-opening reaction sequence.

Asymmetric catalyzed intramolecular aza-Michael reaction mediated by quinine-derived primary amines

An intramolecular organocatalytic enantioselective aza-Michael reaction of carbamates, sulfonamides and acetamides to a,b-unsaturated ketones was developed. This process is promoted by 9-amino-9-deoxy-epi-quinine and diphenyl hydrogen phosphate to afford a straightforward and expeditious synthesis of several synthetically useful five-and six-membered heterocycles with excellent enantioselectivity（92%–97.5% ee） and very good yields（up to 99%）.

An environmentally benign multi-component reaction:Highly regioselective synthesis of functionalized 2-(diarylphosphoryl)-1,2-dihydro-pyridine derivatives

A novel protocol was developed for the construction of highly functionalized 2-(diarylphosphoryl)-1,2-dihydropyridine derivatives(DAPDHPs)from 3-formylchromones(1),heterocyclic ketene aminals(HKAs,2),and phosphine oxides(R_(2)P(O)H,3)via a novel,one-pot cascade reaction.Optimization of the reaction conditions determined that refluxing the mixture of the 3-formylchromones,HKAs,and various R_(2)P(O)H in propylene carbonate(PC)in the presence of triethylamine as a base facilitated the highest yields of the DAPDHP products.This cascade reaction,which involved the cleavage of one C-O bond in the 3-formylchromone substrates and the formation of three new bonds(one C-C,one C-N,and one C-P bond),enabled the synthesis of a small library of DAPDHP products.The dearomatized DAPDHP products were formed by the regioselective nucleophilic addition of the R_(2)P(O)H reagents to the intermediate pyridinium salts 8.This approach has several advantages such as the use of an environmentally-friendly solvent,simple and practical operation(with filtration and washing without column chromatography separation),good yields,and a product with potential biological activity.