Photon induced dissociation investigations of neutral tyramine and dopamine are carried out with synchrotron vacuum uRraviolet photoionization mass spectrometry and theoretical calculations. At low photon energy, only...Photon induced dissociation investigations of neutral tyramine and dopamine are carried out with synchrotron vacuum uRraviolet photoionization mass spectrometry and theoretical calculations. At low photon energy, only molecular ions are measured by virtue of nearthreshold photoionization. While increasing photon energy to 11.7 eV or more, four distinct fragment ions are obtained for tyramine and dopamine, respectively. Besides, the ionization energies of tyramine and dopamine are determined to be 7.984-0.05 and 7.674-0.05 eV by measuring the photoionization efficiency curves of corresponding molecular ions. With help of density function theory calculations, the detailed fragmentation pathways are established as well. These two molecular cations have similar aminoethyl group elimination pathways, CTHsO2＋ （m/z=124） and C7H8O＋ （m/z=108） are supposed to be generated by the McLafferty rearrangement via γ-hydrogen （7-H） shift inducing β-fission. And CH2NH2＋ is proposed to derive from the direct fission of C7-C8 bond. Besides, the McLafferty rearrangement and the C7-C8 bond fission are validated to be dominant dissociation pathways for tyramine and dopamine cations.展开更多
The objective of this review is the determination of tyramine in 13 nonalcoholic beers (Maoshaieer) of Tehran market and survey of it’s probably interaction with monoamine oxidase inhibitor drugs (MAOIs) has been inv...The objective of this review is the determination of tyramine in 13 nonalcoholic beers (Maoshaieer) of Tehran market and survey of it’s probably interaction with monoamine oxidase inhibitor drugs (MAOIs) has been investigated. Tyramine was at the highest levels in Baltika (111.34 ± 8.19 μg/ml) and at the lowest level in Bitmalt (8.01 ± 2.09 μg/ml). Comparing different flavors of malt drinks, the highest tyramine content was shown for classic or normal flavor (average 72.99 ± 30.87 μg/ml), while the lowest value belonged to cantaloupe flavored drinks (average 10.55 ± 1.29 μg/ml). In our study, it is seen that there is a significant difference between import and Iranian non-alcoholic beers, the import ones has more tyramine than Iranians. A number of 10 kinds of 13 samples interact whit MAOIs in one serving (250 ml) usage 18.50 mg. The highest tyramine content of Iranian ones is 17.74 mg/250ml and for import ones is 27.83 mg/250ml.展开更多
Zwitterions have aroused much interest to endow implantable medical devices with anti-fouling and anti-thrombosis performance,due to their ability to form a hydrated layer that can provide a good barrier against prote...Zwitterions have aroused much interest to endow implantable medical devices with anti-fouling and anti-thrombosis performance,due to their ability to form a hydrated layer that can provide a good barrier against protein and cell adhesion. Herein,tyramine modified sulfobetaine-derived sodium hyaluronan(HST) hydrogel coating was fabricated, in which hyaluronan(HA)was used as polysaccharide skeleton to graft zwitterionic sulfobetaine, and tyramine was introduced as crosslinker to construct both the network of hydrogel and a strong covalent bond between coating and substrate. Hydrogel coating was prepared by spin coating or painting HST prepolymer solution under ultraviolet light irradiation. The obtained HST hydrogel coating shows good stability. Moreover, in addition to its outstanding anti-fouling performance and good biocompatibility, it can effectively prevent thrombosis in blood circulation ex vivo. This work offers a universal strategy to prepare a high-performance anti-fouling and antithrombosis coating, which is expected to promote the development of functional coatings for biomedical materials.展开更多
Ferulic acid inclusion complexes(FA-HP-β-CD)effects on tyramine accumulation and gene expression of Enterobacter hormaechei MW386398 in traditional smoked horsemeat sausages were studied.Reverse transcription-quantit...Ferulic acid inclusion complexes(FA-HP-β-CD)effects on tyramine accumulation and gene expression of Enterobacter hormaechei MW386398 in traditional smoked horsemeat sausages were studied.Reverse transcription-quantitative polymerase chain reaction(RT-qPCR)was used to identify the expression of tyrosine decarboxylase(TDC)clusters in the tyramine producing pathway.In addition,relevant parameters such as microbial growth,moisture content,pH,and tyramine accumulation in pure cultures and during fermentation of smoked horsemeat sausages were evaluated.Ferulic acid(FA)and FA-HP-β-CD inclusion complexes both significantly decreased tyramine accumulation,as well as significantly inhibited tyrosine decarboxylase(tdcA)and tyrosine/tyramine antiporter(tyrP)genes expression(p<0.05).Furthermore,FA and FA-HP-β-CD inclusion complexes both reduced the number of Enterobacteriaceae in smoked horsemeat sausages,but did not alter the main microbiota.However,FA-HP-β-CD inclusion complexes exhibited stronger ability in hindering TDC related gene expression,reducing tyramine accumulation and antibacterial properties.These results indicate that FA-HP-β-CD inclusion complexes are able to reduce tyramine accumulation in smoked horsemeat sausages by inhibiting Enterobacteriaceae growth and gene expression.展开更多
To investigate the productions of biogenic amines(BAs)in Pacific white shrimp treated by compound preservatives(P,0.05 g/L quercetin,0.025 g/L 4-hexylresorcinol,and 0.025 g/L cinnamic acid)in combination with modified...To investigate the productions of biogenic amines(BAs)in Pacific white shrimp treated by compound preservatives(P,0.05 g/L quercetin,0.025 g/L 4-hexylresorcinol,and 0.025 g/L cinnamic acid)in combination with modified atmosphere packaging(M,80% CO_(2)/10% O_(2)/10% N_(2)),four groups of samples treated with or without preservatives and alone or in combination with modified atmosphere packaging(A,A+P,M,M+P)during storage at 4℃for 12 days were analyzed.Most BAs increased in all samples,especially,putrescine and cadaverine.MAP inhibited the increase of most BAs(except for tyramine)and psychrotrophic bacterial counts.The inhibitory effect of the compound preservatives on bacterial growth and BAs was limited in aerobically-and MAP-stored samples,but they retarded the production of tyramine,which accumulated more rapidly in MAP.Lowest total BAs and bacterial counts were found in sample M+P(78.3 mg/kg and 5.82 log cfu/g,day 12),indicating that the combined treatment of the preservatives and MAP could reduce the risk of disorders caused by BAs.展开更多
基金Authors thank Dr. Yang Pan for useful discussions This work was supported by the National Natural Science Foundation of China （No.10805047）.
文摘Photon induced dissociation investigations of neutral tyramine and dopamine are carried out with synchrotron vacuum uRraviolet photoionization mass spectrometry and theoretical calculations. At low photon energy, only molecular ions are measured by virtue of nearthreshold photoionization. While increasing photon energy to 11.7 eV or more, four distinct fragment ions are obtained for tyramine and dopamine, respectively. Besides, the ionization energies of tyramine and dopamine are determined to be 7.984-0.05 and 7.674-0.05 eV by measuring the photoionization efficiency curves of corresponding molecular ions. With help of density function theory calculations, the detailed fragmentation pathways are established as well. These two molecular cations have similar aminoethyl group elimination pathways, CTHsO2＋ （m/z=124） and C7H8O＋ （m/z=108） are supposed to be generated by the McLafferty rearrangement via γ-hydrogen （7-H） shift inducing β-fission. And CH2NH2＋ is proposed to derive from the direct fission of C7-C8 bond. Besides, the McLafferty rearrangement and the C7-C8 bond fission are validated to be dominant dissociation pathways for tyramine and dopamine cations.
文摘The objective of this review is the determination of tyramine in 13 nonalcoholic beers (Maoshaieer) of Tehran market and survey of it’s probably interaction with monoamine oxidase inhibitor drugs (MAOIs) has been investigated. Tyramine was at the highest levels in Baltika (111.34 ± 8.19 μg/ml) and at the lowest level in Bitmalt (8.01 ± 2.09 μg/ml). Comparing different flavors of malt drinks, the highest tyramine content was shown for classic or normal flavor (average 72.99 ± 30.87 μg/ml), while the lowest value belonged to cantaloupe flavored drinks (average 10.55 ± 1.29 μg/ml). In our study, it is seen that there is a significant difference between import and Iranian non-alcoholic beers, the import ones has more tyramine than Iranians. A number of 10 kinds of 13 samples interact whit MAOIs in one serving (250 ml) usage 18.50 mg. The highest tyramine content of Iranian ones is 17.74 mg/250ml and for import ones is 27.83 mg/250ml.
基金supported by the National Key Research and Development Program of China (Grant No. 2018YFC1105500)the National Natural Science Foundation of China (Grant Nos. U20A20261,31870948,31971250,and 52073205)the Natural Science Foundation of Tianjin (Grant Nos. 20JCYBJC00660 and 21JCYBJC00560)。
文摘Zwitterions have aroused much interest to endow implantable medical devices with anti-fouling and anti-thrombosis performance,due to their ability to form a hydrated layer that can provide a good barrier against protein and cell adhesion. Herein,tyramine modified sulfobetaine-derived sodium hyaluronan(HST) hydrogel coating was fabricated, in which hyaluronan(HA)was used as polysaccharide skeleton to graft zwitterionic sulfobetaine, and tyramine was introduced as crosslinker to construct both the network of hydrogel and a strong covalent bond between coating and substrate. Hydrogel coating was prepared by spin coating or painting HST prepolymer solution under ultraviolet light irradiation. The obtained HST hydrogel coating shows good stability. Moreover, in addition to its outstanding anti-fouling performance and good biocompatibility, it can effectively prevent thrombosis in blood circulation ex vivo. This work offers a universal strategy to prepare a high-performance anti-fouling and antithrombosis coating, which is expected to promote the development of functional coatings for biomedical materials.
基金This work was supported by grants from the National Natural Science Foundation of China(No.32060547)the key science and technology research projects of Xinjiang production and construction team(No.2020AB012).
文摘Ferulic acid inclusion complexes(FA-HP-β-CD)effects on tyramine accumulation and gene expression of Enterobacter hormaechei MW386398 in traditional smoked horsemeat sausages were studied.Reverse transcription-quantitative polymerase chain reaction(RT-qPCR)was used to identify the expression of tyrosine decarboxylase(TDC)clusters in the tyramine producing pathway.In addition,relevant parameters such as microbial growth,moisture content,pH,and tyramine accumulation in pure cultures and during fermentation of smoked horsemeat sausages were evaluated.Ferulic acid(FA)and FA-HP-β-CD inclusion complexes both significantly decreased tyramine accumulation,as well as significantly inhibited tyrosine decarboxylase(tdcA)and tyrosine/tyramine antiporter(tyrP)genes expression(p<0.05).Furthermore,FA and FA-HP-β-CD inclusion complexes both reduced the number of Enterobacteriaceae in smoked horsemeat sausages,but did not alter the main microbiota.However,FA-HP-β-CD inclusion complexes exhibited stronger ability in hindering TDC related gene expression,reducing tyramine accumulation and antibacterial properties.These results indicate that FA-HP-β-CD inclusion complexes are able to reduce tyramine accumulation in smoked horsemeat sausages by inhibiting Enterobacteriaceae growth and gene expression.
基金The authors gratefully acknowledge the funding from the National Natural Science Foundation of China(31501551)National“13th Five-Year”Key Research and Development Program for Science and Technology Support(2016YFD0400106)+1 种基金Shanghai Science and Technology Key Project on Agriculture from Shanghai Municipal Agricultural Commission((2016)1-1)Shanghai Engineering Research Center Construction Special Fund from Shanghai Municipal Science and Technology Commission(16DZ2280300).
文摘To investigate the productions of biogenic amines(BAs)in Pacific white shrimp treated by compound preservatives(P,0.05 g/L quercetin,0.025 g/L 4-hexylresorcinol,and 0.025 g/L cinnamic acid)in combination with modified atmosphere packaging(M,80% CO_(2)/10% O_(2)/10% N_(2)),four groups of samples treated with or without preservatives and alone or in combination with modified atmosphere packaging(A,A+P,M,M+P)during storage at 4℃for 12 days were analyzed.Most BAs increased in all samples,especially,putrescine and cadaverine.MAP inhibited the increase of most BAs(except for tyramine)and psychrotrophic bacterial counts.The inhibitory effect of the compound preservatives on bacterial growth and BAs was limited in aerobically-and MAP-stored samples,but they retarded the production of tyramine,which accumulated more rapidly in MAP.Lowest total BAs and bacterial counts were found in sample M+P(78.3 mg/kg and 5.82 log cfu/g,day 12),indicating that the combined treatment of the preservatives and MAP could reduce the risk of disorders caused by BAs.
