Methyluracil and 5-nitro-6-methyluracil react with variable molar quantities of benzoyl chloride in acetonitrile-pyridine at room temperature to give 1-N, 3-N-dibenzoyl-6- methyluracil 3b and 1-N-benzoyl-5-nitro-6-met...Methyluracil and 5-nitro-6-methyluracil react with variable molar quantities of benzoyl chloride in acetonitrile-pyridine at room temperature to give 1-N, 3-N-dibenzoyl-6- methyluracil 3b and 1-N-benzoyl-5-nitro-6-methyluracil 4b. The reactive rates of debenzoylation of 3b and 4b were investigated.展开更多
Acetylation and benzoylation reactions of certain aromatic aldehydes, ketones with Vilsmeier-Haack Re- agents using Acetamide and Oxychloride (SOCl2 or POCl3) under conventional (thermal) and non conven- tional [micro...Acetylation and benzoylation reactions of certain aromatic aldehydes, ketones with Vilsmeier-Haack Re- agents using Acetamide and Oxychloride (SOCl2 or POCl3) under conventional (thermal) and non conven- tional [microwave irradiated (MIR), ultrasonic assisted and solvent free mortar pestle (grinding)] conditions. Reactions afforded good to excellent yields of products with both the VH reagents, reaction times were fairly less in the case of [amide/POCl3] than those of [amide/SOCl2] reagent. Reactions are dramatically acceler- ated in under sonicated and microwave irradiations with a trend: MIR (few seconds) >> Sonication (minutes) > Grinding (min) >> thermal (several hrs).展开更多
Superacid ZrO_2:H_2SO_4 showed high activity in Friedel-Crafts benzoylation of benzene and substituted benzenes such an chlorobenzene,toluene and 1,3,5-trimethylbenzene.Benzophenones in 90-100% yields were obtained wi...Superacid ZrO_2:H_2SO_4 showed high activity in Friedel-Crafts benzoylation of benzene and substituted benzenes such an chlorobenzene,toluene and 1,3,5-trimethylbenzene.Benzophenones in 90-100% yields were obtained with catalytic amount of superacid ZrO_2:H_2SO_4.The calcination temperature greatly influenced the acid strength and activity of the superacid ZrO_2:H_2SO_4.The superacid has both Lewis and Bronsted acid sites.The reversibility of Friedel-Crafts benzoylation and transacylation were observed over the superacid.The used superacid could be readily regenerated and showed identical benzoylation activity to toluene.展开更多
Caffeic acid phenethyl ester （CAPE）, the main biologically active component of propolis, has been successfully synthesized from caffeic acid and β-bromoethylbenzene catalyzed by Na2CO3 in a mixed solvent of HMPA-CH...Caffeic acid phenethyl ester （CAPE）, the main biologically active component of propolis, has been successfully synthesized from caffeic acid and β-bromoethylbenzene catalyzed by Na2CO3 in a mixed solvent of HMPA-CH3CN. To better understand the struc^re-activity relationship of CAPE, phenylethyl-monobenzoylcinnamate and phenylethyl-dibenzoylcinnamate were prepared. Meanwhile, the structure of phenylethyl-monobenzoylcinnamate was confirmed by single-crystal X-ray diffiaction.展开更多
A simple reversed phase HPLC method was developed for the determination of Putrescine, Cadaverine and Spermidine (a class of polyamines) in their benzoylated form from external known standards. In the optimization pro...A simple reversed phase HPLC method was developed for the determination of Putrescine, Cadaverine and Spermidine (a class of polyamines) in their benzoylated form from external known standards. In the optimization procedure, a number of parameters were examined: 1) Solvent used in the extraction of standard polyamines (diethyl ether versus chloroform);2) Solvent used in the elution of the polyamine (methanol versus acetonitrile);3) Mode of derivatization and extraction step(s) (derivatization and extraction performed together versus derivatization and extraction performed separately);and 4) Other instrumental parameters (such as UV detection wavelength, gradient profiles). The advantages of our method, relative to the standard Morgan method are: a) decreased chromatographic runtime, b) ease of preparation with good resolution, sensitivity, and reproducibility using a standard RP-HPLC method.展开更多
A novel La complex with methyl-2-pyridyl ketone benzoyl hydrazone has been synthesized and determined by single crystal X-ray diffraction. The crystal is monoclinic with space group C2/c, a =1 7081(3) nm, b =1 ...A novel La complex with methyl-2-pyridyl ketone benzoyl hydrazone has been synthesized and determined by single crystal X-ray diffraction. The crystal is monoclinic with space group C2/c, a =1 7081(3) nm, b =1 5660(3) nm, c =1 3512(3) nm, α=90 00°, β=94 39(1)°, γ=90 00°, V =3 6037(12) nm 3, Z =4 . The complex is a ten-coordinated one with a lanthanum ion surrounded by a N 4O 6 set. The crystal structure is stabilized by hydrogen bonds between water molecules and NO - 3 anions.展开更多
Systematic studies of the thermal decomposition mechanism of benzoyl peroxide(BPO) in ground state, leading to various intermediates, products and the potential energy surface(PES) of possible dissociation reactions w...Systematic studies of the thermal decomposition mechanism of benzoyl peroxide(BPO) in ground state, leading to various intermediates, products and the potential energy surface(PES) of possible dissociation reactions were made computationally. The structures of the transition states and the activation energies for all the paths causing the formation of the reaction products mentioned above were calculated by the AM1 semi-empirical method. This method is shown to to be one predict correctly the preferred pathway for the title reaction. It has been found that in ground state, the thermal decomposition of benzoyl peroxide has two kinds of paths. The first pathway PhC(O)O-OC(O)Ph→PhC(O)O · →Ph · +CO 2 produces finally phenyl radicals and carbon dioxide. And the second pathway PhC(O)OO-C(O)Ph→PhC(O)OO · +PhC(O) · → PhC(O) · +O 2 →Ph · +CO+O 2, via which the reaction takes place only in two steps, produces oxygen and PhC(O) · radicals, and the further thermal dissociation of PhC(O) · is quite difficult because of the high activation energy in ground state. The calculated activation energies and reaction enthalpies are in good agreement with the experimental values. The research results also show that also the thermal dissociation process of the two bonds or the three bonds for the benzoyl peroxide doesn′t take place in ground state.展开更多
A series of novel derivatives of ligustrazine linked with substituted benzoyl guanidine were synthesized. These compounds have not been reported in literature, and their chemical structures were confirmed by IR, ^1H N...A series of novel derivatives of ligustrazine linked with substituted benzoyl guanidine were synthesized. These compounds have not been reported in literature, and their chemical structures were confirmed by IR, ^1H NMR and MS. The results of NHE1 inhibitory activity test showed that compounds I2, I3, I4, I6, and I7 possess more potent NHE1 inhibitory activity than cariporide.展开更多
The polystyrenylphosphonous acid (PSPA) of low polymerization degree was prepared with one step reaction. The reaction mechanism was changed with different initiators. For the reaction with AIBN or BPO as the initia...The polystyrenylphosphonous acid (PSPA) of low polymerization degree was prepared with one step reaction. The reaction mechanism was changed with different initiators. For the reaction with AIBN or BPO as the initiator, there are 2 or 3 series of radical reaction chains and 5 or 9 series of polystyrenyl products. The main products are PSPA without or with the fragment of the initiator H[CH(C6H5)-CH2]n-PO2H2 and C6H5CO2-[CH2CH (C6H5)]n-PO2H2 respectively.展开更多
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.
Benzoyl peroxide(BPO) has been added in wheat flour because of its bleaching effect. However, the abnormal used BPO has caused increasing concern due to its strong oxidization capability which may have adverse effects...Benzoyl peroxide(BPO) has been added in wheat flour because of its bleaching effect. However, the abnormal used BPO has caused increasing concern due to its strong oxidization capability which may have adverse effects on living organisms. Herein, we present a carbon dot(CD)-based fluorescent and colorimetric probe for visually, sensitively and selectively sensing BPO. The addition of BPO could quench the red fluorescence of CDs peaked at 622 and 677 nm, and decrease the absorbance at 613 nm, while increase the absorbance at 450 nm, resulting in a fluorescence turn-off and colorimetric spectral response.Moreover, the CDs had short response time of 10 min and high sensitivity towards BPO with a low limit of detection of 28 nmol/L. The applicability of the CDs in detecting BPO in wheat, noodle and starch samples was further demonstrated, and good recovery results were obtained.展开更多
To find new lead compounds with high biological activity,a series of novel 4-methyl-1,2,3-thiadiazole-5-carboxaldehyde benzoyl hydrazone derivatives were designed and synthesized.Their structures were confirmed by -1H...To find new lead compounds with high biological activity,a series of novel 4-methyl-1,2,3-thiadiazole-5-carboxaldehyde benzoyl hydrazone derivatives were designed and synthesized.Their structures were confirmed by -1H NMR,-（13）C NMR,IR spectrum and elemental analysis.Preliminary bioassay indicated that the title compounds exhibited moderate to strong fungicidal activity against six fungi in vitro at50 μg/mL.Moreover,some of the title compounds exhibited good curative activity against TMV in vivo at500 μg/mL.The structure-activity relationship analysis of compounds against Valsa mali showed that compounds containing halogen at the para position on phenyl exhibited the best activity.Especially compound 8k showed broad spectrum fungicidal activities against Valsa mali,Botrytis cinerea,Pythium aphamdermatum,Rhizoctonia solani,Fusarium moniliforme and Altemaria solani with the EC（50） values of8.20,24.42,15.80,40.53,41.48,and 34.16 μg/mL,respectively.展开更多
A straightforward and efficient method for the synthesis of thiopyran derivatives via three-component reaction of alkyl propiolate, benzoylisothiocyanate or its derivatives and α-haloketones in the presence of triphe...A straightforward and efficient method for the synthesis of thiopyran derivatives via three-component reaction of alkyl propiolate, benzoylisothiocyanate or its derivatives and α-haloketones in the presence of triphenylphosphine under solvent-free conditions at 70℃ without using any catalyst is reported, The method offers several advantages including high yields of products and an easy work-up procedure.展开更多
A series of subshtuted 3'-N-benzoyl taxol analogs [7a￣i] were synthesized by Schotten-Baumann acylation of the key intermediate, 13-O-[(2'R, 3' S) -3'-phenylisoserinoyl]baccatin Ⅲ[6]. Evaluation of t...A series of subshtuted 3'-N-benzoyl taxol analogs [7a￣i] were synthesized by Schotten-Baumann acylation of the key intermediate, 13-O-[(2'R, 3' S) -3'-phenylisoserinoyl]baccatin Ⅲ[6]. Evaluation of the newly ￣ derivatives for cytotoxicity against KB Cell line revealed that electrondon-donating groups at the para position (such as -CH3, -OCH3, etc.) havepositive effect on achvity, while electron-attracting groups(such as -NO2, -Br, etc.) have negativeeffect. Sterically hindered substituents at the ortho position could dramatically reduce the activity.But none of the analogs had higher cytotoxicity than taxol.展开更多
Here,a new designed core/satellite gold nanoprobe was developed for detecting trace mount of benzoyl peroxide(BPO) based on its deboronation.This gold nanoassembly(the BE-Au NPs_(12/65)) wa s constructed via borate es...Here,a new designed core/satellite gold nanoprobe was developed for detecting trace mount of benzoyl peroxide(BPO) based on its deboronation.This gold nanoassembly(the BE-Au NPs_(12/65)) wa s constructed via borate ester formation between large 4-mercaptophenylboronic acid(MPBA) modified Au NPs(the MPBAAu NPs_(65),as cores) and small dopamine modified AuNPs(the D PA-AuNPs_(12),as satellites).Particularly,upon addition of BPO,it would trigger the deboronation for the BE-AuNPs_(12/65) probes accompanying with distinct color changes from blue,purple to wine red,which implied the disassembly of the core/satellite nanostructure after the breakage of carbon to boron chemical bond.By measuring the absorbance ratio at 665 nm and 545 nm,quantification of BPO was achieved in the range of 10.0-100.0 nmol/L,which could also be easily observed by naked eyes.The nanoprobe utilized a boronate deprotection mechanism and the LSPR properties of Au NPs to provide high selectivity for detecting BPO over similar ROS/RNS with the limit of detection as low as 7.2 nmol/L.The practical applicability of this assay was verified through successful determining BPO in flour samples,which demonstrated its great potentials in food safety field.展开更多
Dimerization Constant of 6-O-benzoyl-β-CD,which is insoluble in water,was determined for the first time by a calculation method involving an approximation step as well as a geometric step.This calculation method can ...Dimerization Constant of 6-O-benzoyl-β-CD,which is insoluble in water,was determined for the first time by a calculation method involving an approximation step as well as a geometric step.This calculation method can be applied to other functionally modified cyclodextrin host compounds.展开更多
Three crystal architectures, including one organic compound of benzoyl peroxide（Ⅰ） and two clusters of tri-iron（Ⅲ） and bi-cupper（Ⅱ） with benzoic ligands（2 and 3）, were self-assembled by an in situ redox way...Three crystal architectures, including one organic compound of benzoyl peroxide（Ⅰ） and two clusters of tri-iron（Ⅲ） and bi-cupper（Ⅱ） with benzoic ligands（2 and 3）, were self-assembled by an in situ redox way of benzoyl peroxide oxidants reacting with Mo, Fe and Cu powders, respectively. X-ray crystallographic results show that both the asymmetry tri-iron（Ⅲ） cluster and the benzoylperoxide crystal architecture（2 and 1） with complicated 3D networks were constructed by intermolecular hydrogen-bonding interactions. Contrarily, the symmetrical bi-copper（Ⅱ） cluster crystal architecture（3）, only with π-π stacking between paralleled phenyl groups and without any intermolecular hydrogen-bonding interactions, only presented an 1D zigzag chain along the a-axis.展开更多
Modified chitosans with 3,4-di-hydroxy benzoyl groups （CS-DHBA） and 3,4,5-tri-hydroxy benzoyl groups （CS- THBA） were synthesized and their nanoparticles were prepared via ionic crosslinking by tripolyphosphate （...Modified chitosans with 3,4-di-hydroxy benzoyl groups （CS-DHBA） and 3,4,5-tri-hydroxy benzoyl groups （CS- THBA） were synthesized and their nanoparticles were prepared via ionic crosslinking by tripolyphosphate （TPP）. The chemical structure and degree of substitution （DS） of di- and tri-hydroxy benzoyl chitosans are determined by FTIR and IH- NMR spectroscopy. The morphology of particles, size distribution and zeta potential of nanoparticles were studied using transmission electron microscopy （TEM） and dynamic light scattering （DLS）, respectively. The mean diameters of particles of CS-DHBA and CS-THBA nanoparticles were 144 nm and 112 nm, respectively. It was found that the particles size decreased slightly with decreasing the degree of substitution and increasing degree of deacetylation （DD）, due to increasing of ionic crosslinking of ammonium ions and polyanions of tripolyphosphate. The TEM photographs of CS-DHBA show that these particles are spherical in shape, but the particles of CS-THBA show some aggregation. In addition, the solubility and the mechanical properties of the prepared modified chitosans and their nanoparticles were evaluated for bio-adhesive and biomedical application. The results of solubility tests indicated that, the CS-DHBA and CS-THBA have higher solubility at pH 〉 7 comparing to CS. Also the CS-DHBA, CS-THBA and their nanoparticles showed a significant adhesive capacity and enhanced tensile strength and tensile modulus.展开更多
基金We thank the National Natural Science Foundation of China(NO．20172007)for financial support
文摘Methyluracil and 5-nitro-6-methyluracil react with variable molar quantities of benzoyl chloride in acetonitrile-pyridine at room temperature to give 1-N, 3-N-dibenzoyl-6- methyluracil 3b and 1-N-benzoyl-5-nitro-6-methyluracil 4b. The reactive rates of debenzoylation of 3b and 4b were investigated.
文摘Acetylation and benzoylation reactions of certain aromatic aldehydes, ketones with Vilsmeier-Haack Re- agents using Acetamide and Oxychloride (SOCl2 or POCl3) under conventional (thermal) and non conven- tional [microwave irradiated (MIR), ultrasonic assisted and solvent free mortar pestle (grinding)] conditions. Reactions afforded good to excellent yields of products with both the VH reagents, reaction times were fairly less in the case of [amide/POCl3] than those of [amide/SOCl2] reagent. Reactions are dramatically acceler- ated in under sonicated and microwave irradiations with a trend: MIR (few seconds) >> Sonication (minutes) > Grinding (min) >> thermal (several hrs).
文摘Superacid ZrO_2:H_2SO_4 showed high activity in Friedel-Crafts benzoylation of benzene and substituted benzenes such an chlorobenzene,toluene and 1,3,5-trimethylbenzene.Benzophenones in 90-100% yields were obtained with catalytic amount of superacid ZrO_2:H_2SO_4.The calcination temperature greatly influenced the acid strength and activity of the superacid ZrO_2:H_2SO_4.The superacid has both Lewis and Bronsted acid sites.The reversibility of Friedel-Crafts benzoylation and transacylation were observed over the superacid.The used superacid could be readily regenerated and showed identical benzoylation activity to toluene.
基金National Natural Science Foundation of China (Grant No. 20672008, 20972011)
文摘Caffeic acid phenethyl ester （CAPE）, the main biologically active component of propolis, has been successfully synthesized from caffeic acid and β-bromoethylbenzene catalyzed by Na2CO3 in a mixed solvent of HMPA-CH3CN. To better understand the struc^re-activity relationship of CAPE, phenylethyl-monobenzoylcinnamate and phenylethyl-dibenzoylcinnamate were prepared. Meanwhile, the structure of phenylethyl-monobenzoylcinnamate was confirmed by single-crystal X-ray diffiaction.
文摘A simple reversed phase HPLC method was developed for the determination of Putrescine, Cadaverine and Spermidine (a class of polyamines) in their benzoylated form from external known standards. In the optimization procedure, a number of parameters were examined: 1) Solvent used in the extraction of standard polyamines (diethyl ether versus chloroform);2) Solvent used in the elution of the polyamine (methanol versus acetonitrile);3) Mode of derivatization and extraction step(s) (derivatization and extraction performed together versus derivatization and extraction performed separately);and 4) Other instrumental parameters (such as UV detection wavelength, gradient profiles). The advantages of our method, relative to the standard Morgan method are: a) decreased chromatographic runtime, b) ease of preparation with good resolution, sensitivity, and reproducibility using a standard RP-HPLC method.
基金Supported by the National Natural Science Foundation of China( No. 2 98710 14 ) and the Foundation of Doctor byL anzhou U niversit
文摘A novel La complex with methyl-2-pyridyl ketone benzoyl hydrazone has been synthesized and determined by single crystal X-ray diffraction. The crystal is monoclinic with space group C2/c, a =1 7081(3) nm, b =1 5660(3) nm, c =1 3512(3) nm, α=90 00°, β=94 39(1)°, γ=90 00°, V =3 6037(12) nm 3, Z =4 . The complex is a ten-coordinated one with a lanthanum ion surrounded by a N 4O 6 set. The crystal structure is stabilized by hydrogen bonds between water molecules and NO - 3 anions.
基金Supported by National NaturalScienceFoundation of China( No.2 97730 0 7) and the NaturalScienceFoundation of Qu-jing Normal College( No.2 0 0 0 0 9)
文摘Systematic studies of the thermal decomposition mechanism of benzoyl peroxide(BPO) in ground state, leading to various intermediates, products and the potential energy surface(PES) of possible dissociation reactions were made computationally. The structures of the transition states and the activation energies for all the paths causing the formation of the reaction products mentioned above were calculated by the AM1 semi-empirical method. This method is shown to to be one predict correctly the preferred pathway for the title reaction. It has been found that in ground state, the thermal decomposition of benzoyl peroxide has two kinds of paths. The first pathway PhC(O)O-OC(O)Ph→PhC(O)O · →Ph · +CO 2 produces finally phenyl radicals and carbon dioxide. And the second pathway PhC(O)OO-C(O)Ph→PhC(O)OO · +PhC(O) · → PhC(O) · +O 2 →Ph · +CO+O 2, via which the reaction takes place only in two steps, produces oxygen and PhC(O) · radicals, and the further thermal dissociation of PhC(O) · is quite difficult because of the high activation energy in ground state. The calculated activation energies and reaction enthalpies are in good agreement with the experimental values. The research results also show that also the thermal dissociation process of the two bonds or the three bonds for the benzoyl peroxide doesn′t take place in ground state.
文摘A series of novel derivatives of ligustrazine linked with substituted benzoyl guanidine were synthesized. These compounds have not been reported in literature, and their chemical structures were confirmed by IR, ^1H NMR and MS. The results of NHE1 inhibitory activity test showed that compounds I2, I3, I4, I6, and I7 possess more potent NHE1 inhibitory activity than cariporide.
文摘The polystyrenylphosphonous acid (PSPA) of low polymerization degree was prepared with one step reaction. The reaction mechanism was changed with different initiators. For the reaction with AIBN or BPO as the initiator, there are 2 or 3 series of radical reaction chains and 5 or 9 series of polystyrenyl products. The main products are PSPA without or with the fragment of the initiator H[CH(C6H5)-CH2]n-PO2H2 and C6H5CO2-[CH2CH (C6H5)]n-PO2H2 respectively.
文摘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.
基金supported by National Natural Science Foundation of China (Nos. 61805287, 62175262)Natural Science Foundation of Hunan Province,China (No. 2019JJ50824)+1 种基金Fundamental Research Funds for the Central South Universities (Nos. 2020CX021,2020zzts387)Basic Research Foundation of Shenzhen Science and Technology Innovation (No. JCYJ20180307151245919)。
文摘Benzoyl peroxide(BPO) has been added in wheat flour because of its bleaching effect. However, the abnormal used BPO has caused increasing concern due to its strong oxidization capability which may have adverse effects on living organisms. Herein, we present a carbon dot(CD)-based fluorescent and colorimetric probe for visually, sensitively and selectively sensing BPO. The addition of BPO could quench the red fluorescence of CDs peaked at 622 and 677 nm, and decrease the absorbance at 613 nm, while increase the absorbance at 450 nm, resulting in a fluorescence turn-off and colorimetric spectral response.Moreover, the CDs had short response time of 10 min and high sensitivity towards BPO with a low limit of detection of 28 nmol/L. The applicability of the CDs in detecting BPO in wheat, noodle and starch samples was further demonstrated, and good recovery results were obtained.
基金financial support from the National Natural Science Foundation of China(No.21132003)
文摘To find new lead compounds with high biological activity,a series of novel 4-methyl-1,2,3-thiadiazole-5-carboxaldehyde benzoyl hydrazone derivatives were designed and synthesized.Their structures were confirmed by -1H NMR,-（13）C NMR,IR spectrum and elemental analysis.Preliminary bioassay indicated that the title compounds exhibited moderate to strong fungicidal activity against six fungi in vitro at50 μg/mL.Moreover,some of the title compounds exhibited good curative activity against TMV in vivo at500 μg/mL.The structure-activity relationship analysis of compounds against Valsa mali showed that compounds containing halogen at the para position on phenyl exhibited the best activity.Especially compound 8k showed broad spectrum fungicidal activities against Valsa mali,Botrytis cinerea,Pythium aphamdermatum,Rhizoctonia solani,Fusarium moniliforme and Altemaria solani with the EC（50） values of8.20,24.42,15.80,40.53,41.48,and 34.16 μg/mL,respectively.
文摘A straightforward and efficient method for the synthesis of thiopyran derivatives via three-component reaction of alkyl propiolate, benzoylisothiocyanate or its derivatives and α-haloketones in the presence of triphenylphosphine under solvent-free conditions at 70℃ without using any catalyst is reported, The method offers several advantages including high yields of products and an easy work-up procedure.
文摘A series of subshtuted 3'-N-benzoyl taxol analogs [7a￣i] were synthesized by Schotten-Baumann acylation of the key intermediate, 13-O-[(2'R, 3' S) -3'-phenylisoserinoyl]baccatin Ⅲ[6]. Evaluation of the newly ￣ derivatives for cytotoxicity against KB Cell line revealed that electrondon-donating groups at the para position (such as -CH3, -OCH3, etc.) havepositive effect on achvity, while electron-attracting groups(such as -NO2, -Br, etc.) have negativeeffect. Sterically hindered substituents at the ortho position could dramatically reduce the activity.But none of the analogs had higher cytotoxicity than taxol.
基金financial support from the National Natural Science Foundation of China(Nos.U1736201,21677019 and 41403021)Capital Health Research and Development of Special(No.2018-4-1014)the Key Research and Development Program of Beijing(No.D171100008317001)。
文摘Here,a new designed core/satellite gold nanoprobe was developed for detecting trace mount of benzoyl peroxide(BPO) based on its deboronation.This gold nanoassembly(the BE-Au NPs_(12/65)) wa s constructed via borate ester formation between large 4-mercaptophenylboronic acid(MPBA) modified Au NPs(the MPBAAu NPs_(65),as cores) and small dopamine modified AuNPs(the D PA-AuNPs_(12),as satellites).Particularly,upon addition of BPO,it would trigger the deboronation for the BE-AuNPs_(12/65) probes accompanying with distinct color changes from blue,purple to wine red,which implied the disassembly of the core/satellite nanostructure after the breakage of carbon to boron chemical bond.By measuring the absorbance ratio at 665 nm and 545 nm,quantification of BPO was achieved in the range of 10.0-100.0 nmol/L,which could also be easily observed by naked eyes.The nanoprobe utilized a boronate deprotection mechanism and the LSPR properties of Au NPs to provide high selectivity for detecting BPO over similar ROS/RNS with the limit of detection as low as 7.2 nmol/L.The practical applicability of this assay was verified through successful determining BPO in flour samples,which demonstrated its great potentials in food safety field.
文摘Dimerization Constant of 6-O-benzoyl-β-CD,which is insoluble in water,was determined for the first time by a calculation method involving an approximation step as well as a geometric step.This calculation method can be applied to other functionally modified cyclodextrin host compounds.
基金Supported by the National Natural Science Foundation of China(No.20771073)
文摘Three crystal architectures, including one organic compound of benzoyl peroxide（Ⅰ） and two clusters of tri-iron（Ⅲ） and bi-cupper（Ⅱ） with benzoic ligands（2 and 3）, were self-assembled by an in situ redox way of benzoyl peroxide oxidants reacting with Mo, Fe and Cu powders, respectively. X-ray crystallographic results show that both the asymmetry tri-iron（Ⅲ） cluster and the benzoylperoxide crystal architecture（2 and 1） with complicated 3D networks were constructed by intermolecular hydrogen-bonding interactions. Contrarily, the symmetrical bi-copper（Ⅱ） cluster crystal architecture（3）, only with π-π stacking between paralleled phenyl groups and without any intermolecular hydrogen-bonding interactions, only presented an 1D zigzag chain along the a-axis.
文摘Modified chitosans with 3,4-di-hydroxy benzoyl groups （CS-DHBA） and 3,4,5-tri-hydroxy benzoyl groups （CS- THBA） were synthesized and their nanoparticles were prepared via ionic crosslinking by tripolyphosphate （TPP）. The chemical structure and degree of substitution （DS） of di- and tri-hydroxy benzoyl chitosans are determined by FTIR and IH- NMR spectroscopy. The morphology of particles, size distribution and zeta potential of nanoparticles were studied using transmission electron microscopy （TEM） and dynamic light scattering （DLS）, respectively. The mean diameters of particles of CS-DHBA and CS-THBA nanoparticles were 144 nm and 112 nm, respectively. It was found that the particles size decreased slightly with decreasing the degree of substitution and increasing degree of deacetylation （DD）, due to increasing of ionic crosslinking of ammonium ions and polyanions of tripolyphosphate. The TEM photographs of CS-DHBA show that these particles are spherical in shape, but the particles of CS-THBA show some aggregation. In addition, the solubility and the mechanical properties of the prepared modified chitosans and their nanoparticles were evaluated for bio-adhesive and biomedical application. The results of solubility tests indicated that, the CS-DHBA and CS-THBA have higher solubility at pH 〉 7 comparing to CS. Also the CS-DHBA, CS-THBA and their nanoparticles showed a significant adhesive capacity and enhanced tensile strength and tensile modulus.
