To investigate the effect of reduced salinity on diatoms’ capacity to cope with changing ultraviolet radiation(U VR) and photosynthetically active radiation(PAR),Skeletonema costatum was grown in a range of salinity(...To investigate the effect of reduced salinity on diatoms’ capacity to cope with changing ultraviolet radiation(U VR) and photosynthetically active radiation(PAR),Skeletonema costatum was grown in a range of salinity(15,25,and 35).The photo system Ⅱ(PSⅡ) function was analyzed by increasing PAR and UVR to mimic a mixing event in turbulent waters.The re sults show that high UVR exposure significantly reduced PSII activity,especially in cells grown at low salinity.UVR,but not salinity,stimulated the ’removal’ rate of PSII protein PsbA.Salinity alone,in the range of 15 to 35,did not regulate PSⅡ acceptor region;however,the low salinity+UVR treatment decreased the energy flux for electron transport per PSⅡ reaction center in S.costatum.It showed that low salinity exacerbated the damaging effect of UVR on PSⅡ function in S.costatum by suppressing Psb A protein synthe sis and modifying the photochemistry of PSⅡ.Although higher catalase(CAT) activity and NPQs were induced,they were unable to prevent the combined damage effect of low salinity+UVR.Our findings indicate that reduced salinity and increased UVR potentially affect the abundance and distribution of S.costatum with the escalation of climate disturbances.展开更多
It has been shown by the results-of HPLC analysis in combination with spectrographicdeterminations that PsD-007 is composed of 7 different porphyrins,In order of the proportion inPsD-007,they are:3 （or 8）-（l-methox...It has been shown by the results-of HPLC analysis in combination with spectrographicdeterminations that PsD-007 is composed of 7 different porphyrins,In order of the proportion inPsD-007,they are:3 （or 8）-（l-methoxyethyl）-8 （or 3）-（l-hydroxyethyl）-deuteroporphyrin Ⅸ（MHD）;3,8-di-（l-methoxyethyl）-deuteroporphyrin Ⅸ（DMD）;3（or 8）-（l-methoxyethyl）-8 （or3）-vinyl-deuteroporphyrin Ⅸ（MVD）;3（or 8）-（l-hydroxyethyl）-8（or 3）-vinyl-deuteroporphyrin Ⅸ（HVD）;hernatoporphyrin Ⅸ （Hp）;protoporphyrin Ⅸ （Pp） and 3（or 8）-（O-aceylethyl）-8（or 3）-（l-hydroxyethyl）-deuteroporphrin Ⅸ （AHD）,which presented only in crude PsD-007 and hasbeen transformed into MHD and Hp,respectively during the separation and preparing the clinicalpreparation of PsD-007.Structures of these porphyrins were further eonfirmed by the corre-sponding anthentic samples obtained by synthetic method.It was found on the basis of the experi-mental data of photosensitizing ability in cell-free systems and photoinactivation of human cancercells in vitro as well as efficacy of photodynamic therapy for sarcoma.S<sub>180</sub> in mice of the ma-jor components MILD,DMD and MVD composed of which more over 85% of the totalamount of PsD-007,that they all exhibited comparatively high photosensitizing ability andphotodynamic effects on cancer cells and tram-planted animal tumor.展开更多
Coronavirus disease 2019 is a serious disease that causes acute respiratory syndrome and negatively affects the central nervous system.Severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)crosses the blood-brain...Coronavirus disease 2019 is a serious disease that causes acute respiratory syndrome and negatively affects the central nervous system.Severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)crosses the blood-brain barrier due to the spike(S) protein on the surface of the viral particles.Thus,it is important to develop compounds that not only have an inhibitory effect but are also capable of completely deactivating the S protein function.This study describes the purposeful modification of porphyrins and proposes compounds,asymmetrically hetaryl-substituted porphyrins with benzothiazole,benzoxazole,and N-methylbenzimidazole residues,to deactivate the S protein functions.Molecular docking of SARS-CoV-2 proteins with hetaryl-substituted porphyrins showed that the viral S protein,nucleocapsid(N) protein,and non-structural protein 13(nsp13) exhibited the highest binding affinity.Hetaryl-substituted porphyrins form strong complexes(13-14 kcal/mol) with the receptor-binding domain of the S protein,while the distance from the porphyrins to the receptor-binding motif(RBM)does not exceed 20 ?;therefore,RBM can be oxidized by ^(1)O_(2),which is generated by porphyrin.Hetarylsubstituted porphyrins interact with the N protein in the serine/arginine-rich region,and a number of vulnerable amino acid residues are located in the photooxidation zone.This damage complicates the packaging of viral RNA into new virions.High-energy binding of hetaryl-substituted porphyrins with the N-and C-terminal domains of nsp13 was observed.This binding blocks the action of nsp13 as an enzyme of exoribonuclease and methyltransferase,thereby preventing RNA replication and processing.A procedure for the synthesis of hetaryl-substituted porphyrins was developed,new compounds were obtained,their structures were identified,and their photocatalytic properties were studied.展开更多
Microbial contamination of cereal grains intended for sprouting poses a significant food safety challenge,as conventional decontamination methods often compromise seed viability and nutritional quality.This study asse...Microbial contamination of cereal grains intended for sprouting poses a significant food safety challenge,as conventional decontamination methods often compromise seed viability and nutritional quality.This study assessed the antimicrobial efficacy and safety of two visible-light-activated systems,zinc oxide nanoparticles(ZnO NPs)and a chlorophyllin-chitosan(Chl-CHS)complex,for wheat seed decontamination.Antibacterial efficacy was tested against Listeria monocytogenes and Escherichia coli in vitro,while antifungal effectiveness was evaluated against yeast and mold populations naturally occurring on wheat seeds.Under visible light,ZnO NPs demonstrated rapid,broad-spectrum bactericidal activity,reducing L.monocytogenes and E.coli by>3 log10 at light doses of 22 and 30 J/cm^(2),respectively.The Chl-CHS complex exhibited strong photodynamic efficacy against L.monocytogenes,achieving bactericidal inactivation at a lower light dose(3 J/cm^(2);10 min incubation),while E.coli required higher light exposure(45 J/cm2)and longer incubation(60 min).Fungal populations decreased by 68-75%from the original yeast and mold count of approximately 4 log CFU/g.Germination tests indicated that neither treatment negatively impacted seed viability or sprouting over a fiveday period.Total antioxidant capacity remained unchanged compared to untreated controls,indicating that the nutritional quality was preserved.Electron paramagnetic resonance spectroscopy further validated the treat-ments’safety,as no increase in integrated radical signals was observed after photoactivation,unlike ionizing radiation,which produced stable free radicals.In summary,visible-light-driven antimicrobial treatments using ZnO NPs and Chl-CHS complex offer an effective,non-thermal,and seed-safe approach for enhancing the microbiological safety of wheat seeds and sprouts.展开更多
基金Supported by the Shandong Provincial Natural Science Foundation(Nos.ZR2019MC015,ZR2020QC025,ZR2020MD092)the open project of Rongcheng Marine Industrial Technology Research Institute,Ludong University(No.KF20180001)the Key Technology Research and Development Program of Shandong(No.2019GSF107091)。
文摘To investigate the effect of reduced salinity on diatoms’ capacity to cope with changing ultraviolet radiation(U VR) and photosynthetically active radiation(PAR),Skeletonema costatum was grown in a range of salinity(15,25,and 35).The photo system Ⅱ(PSⅡ) function was analyzed by increasing PAR and UVR to mimic a mixing event in turbulent waters.The re sults show that high UVR exposure significantly reduced PSII activity,especially in cells grown at low salinity.UVR,but not salinity,stimulated the ’removal’ rate of PSII protein PsbA.Salinity alone,in the range of 15 to 35,did not regulate PSⅡ acceptor region;however,the low salinity+UVR treatment decreased the energy flux for electron transport per PSⅡ reaction center in S.costatum.It showed that low salinity exacerbated the damaging effect of UVR on PSⅡ function in S.costatum by suppressing Psb A protein synthe sis and modifying the photochemistry of PSⅡ.Although higher catalase(CAT) activity and NPQs were induced,they were unable to prevent the combined damage effect of low salinity+UVR.Our findings indicate that reduced salinity and increased UVR potentially affect the abundance and distribution of S.costatum with the escalation of climate disturbances.
文摘It has been shown by the results-of HPLC analysis in combination with spectrographicdeterminations that PsD-007 is composed of 7 different porphyrins,In order of the proportion inPsD-007,they are:3 （or 8）-（l-methoxyethyl）-8 （or 3）-（l-hydroxyethyl）-deuteroporphyrin Ⅸ（MHD）;3,8-di-（l-methoxyethyl）-deuteroporphyrin Ⅸ（DMD）;3（or 8）-（l-methoxyethyl）-8 （or3）-vinyl-deuteroporphyrin Ⅸ（MVD）;3（or 8）-（l-hydroxyethyl）-8（or 3）-vinyl-deuteroporphyrin Ⅸ（HVD）;hernatoporphyrin Ⅸ （Hp）;protoporphyrin Ⅸ （Pp） and 3（or 8）-（O-aceylethyl）-8（or 3）-（l-hydroxyethyl）-deuteroporphrin Ⅸ （AHD）,which presented only in crude PsD-007 and hasbeen transformed into MHD and Hp,respectively during the separation and preparing the clinicalpreparation of PsD-007.Structures of these porphyrins were further eonfirmed by the corre-sponding anthentic samples obtained by synthetic method.It was found on the basis of the experi-mental data of photosensitizing ability in cell-free systems and photoinactivation of human cancercells in vitro as well as efficacy of photodynamic therapy for sarcoma.S<sub>180</sub> in mice of the ma-jor components MILD,DMD and MVD composed of which more over 85% of the totalamount of PsD-007,that they all exhibited comparatively high photosensitizing ability andphotodynamic effects on cancer cells and tram-planted animal tumor.
文摘Coronavirus disease 2019 is a serious disease that causes acute respiratory syndrome and negatively affects the central nervous system.Severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)crosses the blood-brain barrier due to the spike(S) protein on the surface of the viral particles.Thus,it is important to develop compounds that not only have an inhibitory effect but are also capable of completely deactivating the S protein function.This study describes the purposeful modification of porphyrins and proposes compounds,asymmetrically hetaryl-substituted porphyrins with benzothiazole,benzoxazole,and N-methylbenzimidazole residues,to deactivate the S protein functions.Molecular docking of SARS-CoV-2 proteins with hetaryl-substituted porphyrins showed that the viral S protein,nucleocapsid(N) protein,and non-structural protein 13(nsp13) exhibited the highest binding affinity.Hetaryl-substituted porphyrins form strong complexes(13-14 kcal/mol) with the receptor-binding domain of the S protein,while the distance from the porphyrins to the receptor-binding motif(RBM)does not exceed 20 ?;therefore,RBM can be oxidized by ^(1)O_(2),which is generated by porphyrin.Hetarylsubstituted porphyrins interact with the N protein in the serine/arginine-rich region,and a number of vulnerable amino acid residues are located in the photooxidation zone.This damage complicates the packaging of viral RNA into new virions.High-energy binding of hetaryl-substituted porphyrins with the N-and C-terminal domains of nsp13 was observed.This binding blocks the action of nsp13 as an enzyme of exoribonuclease and methyltransferase,thereby preventing RNA replication and processing.A procedure for the synthesis of hetaryl-substituted porphyrins was developed,new compounds were obtained,their structures were identified,and their photocatalytic properties were studied.
文摘Microbial contamination of cereal grains intended for sprouting poses a significant food safety challenge,as conventional decontamination methods often compromise seed viability and nutritional quality.This study assessed the antimicrobial efficacy and safety of two visible-light-activated systems,zinc oxide nanoparticles(ZnO NPs)and a chlorophyllin-chitosan(Chl-CHS)complex,for wheat seed decontamination.Antibacterial efficacy was tested against Listeria monocytogenes and Escherichia coli in vitro,while antifungal effectiveness was evaluated against yeast and mold populations naturally occurring on wheat seeds.Under visible light,ZnO NPs demonstrated rapid,broad-spectrum bactericidal activity,reducing L.monocytogenes and E.coli by>3 log10 at light doses of 22 and 30 J/cm^(2),respectively.The Chl-CHS complex exhibited strong photodynamic efficacy against L.monocytogenes,achieving bactericidal inactivation at a lower light dose(3 J/cm^(2);10 min incubation),while E.coli required higher light exposure(45 J/cm2)and longer incubation(60 min).Fungal populations decreased by 68-75%from the original yeast and mold count of approximately 4 log CFU/g.Germination tests indicated that neither treatment negatively impacted seed viability or sprouting over a fiveday period.Total antioxidant capacity remained unchanged compared to untreated controls,indicating that the nutritional quality was preserved.Electron paramagnetic resonance spectroscopy further validated the treat-ments’safety,as no increase in integrated radical signals was observed after photoactivation,unlike ionizing radiation,which produced stable free radicals.In summary,visible-light-driven antimicrobial treatments using ZnO NPs and Chl-CHS complex offer an effective,non-thermal,and seed-safe approach for enhancing the microbiological safety of wheat seeds and sprouts.
