油酸和十二烷二酸的氨基酸酯合成及其抗菌性

以L-丙氨酸乙酯盐酸盐、甘氨酸乙酯盐酸盐、L-蛋氨酸甲酯盐酸盐、L-亮氨酸乙酯盐酸盐和L-酪氨酸甲酯盐酸盐在1-乙基-(3-二甲基氨基丙基)碳酰二亚胺盐酸盐和1-羟基苯并三唑(HOBt)的作用下分别与油酸进行反应,生成了5种油酸的氨基酸衍生物;将L-丙氨酸乙酯盐酸盐和甘氨酸乙酯盐酸盐分别与十二烷二酸进行反应,生成了两种十二烷二酸的氨基酸衍生物,7种产物的收率均≥75%。利用FTIR、TGA、1HNMR和LC-MS对产物进行了表征,测试了产物的水油分散性,考察了产物对金黄色葡萄球菌和大肠杆菌的抑菌性。结果表明,所合成的脂肪酰氨基酸酯均能在水油体系中分散,且具有较强的生物抗菌性,其中,0.01 mg油酸酰亮氨酸乙酯能有效地抑制金黄色葡萄球菌(菌数由2.0×109CFU/mL降至1.4×10^(7)CFU/mL),而相同质量油酸酰酪氨酸甲酯则能抑制大肠杆菌(菌数由2.0×10^(9)CFU/mL降至1.8×10^(7)CFU/mL)。

含氮羧酸的羟乙基甲硝唑酯的合成

为寻找羟乙基甲硝唑的替代物 ,分别采用酸酐法、酰氯法或DCC法 ,将氨基羧酸与羟乙基甲硝唑反应 ,得到 5个亲水性不同的单酯或二酯 ,用MS谱确证了次氨基三乙酸与乙酸酐反应的中间物 ,并对得到的酯的1H NMR谱进行了初步研究。 3个二酯中 ,有

Adsorption and flotation mechanism of a ketoxime-dithiocarbonate surfactant to chalcopyrite

The adsorption mechanism of O-isopropyl-S-[2-(hydroxyimino) propyl] dithiocarbonate ester(IPXPO) to chalcopyrite was investigated by using contact angle, in-situ atomic force microscopy(in-situ AFM), cyclic voltammetry(CV) and X-ray photoelectron spectroscopy(XPS). The results of contact angle and in-situ AFM demonstrated that IPXPO adsorbed on chalcopyrite increases surface hydrophobicity and roughness. It was found by CV experiments that a layer passive film was formed. The results of XPS spectra further revealed that the thiol S atom, oxime N atom, and O atom in the IPXPO molecule might react with copper atoms to form Cu-S, Cu-N, and Cu-O bonds, respectively. An artificial mixed minerals flotation test indicated that under the condition of pH=6.79 and IPXPO initial concentration 5×10^(-5)mol/L, the flotation recovery of chalcopyrite reached about 90%, while for pyrite only 25%, suggesting that IPXPO is an excellent collector for flotation separation and enrichment of chalcopyrite.

Kinetics of the decomposition of dimethylhexane-1,6-dicarbamate to1,6-hexamethylene diisocyanate

The kinetics of the decomposition of dimethylhexane-1,6-dicarbamate to 1,6-hexamethylene diisocyanate was studied. A consecutive reaction model was established and the reaction orders for the two steps were confirmed to be 1 and 1.3 by the integral test method and the numerical differential method, respectively. The activation energies of the two steps were （56.94 4±5.90） kJ·mol^-1 and （72.07±3.47） kJ·mol^-1 with the frequency factors exp（ 12.53±1.42） min^- 1 and （ 14.254±0.84） tool^-0.33. L^0.33·min^-1, respectively. Based on the kinetic model obtained, the progress of the reaction can be calculated under given conditions.

Synthesis of novel thionocarbamate for copper-sulfur flotation separation and its adsorption mechanism

As a novel collector, O-isopropyl-N,N-diethyl thionocarbamate(IPDTC) was designed and synthesized for copper-sulfur flotation separation. Density functional theory calculations were performed to investigate the electronic structures of IPDTC. The results showed that IPDTC had higher energy of the highest occupied molecular orbital but lower electronegativity than O-isopropyl-N-ethyl thionocarbamate(Z-200). It was predicted that IPDTC had strong collection ability according to the reaction energy criteria. Flotation results demonstrated that the collecting ability of IPDTC to chalcopyrite and pyrite was stronger than that of Z-200. Then, the flotation mechanism was analyzed by measurements of surface tension, adsorption capacity, XPS, FTIR and zeta potential. These results indicated that IPDTC could reduce the solution surface tension. The adsorption capacity of IPDTC on chalcopyrite was higher than that on pyrite, consistent with the results of the flotation tests. FTIR, zeta potential and XPS results also demonstrated that IPDTC was strongly absorbed on the chalcopyrite surface by formation of Cu—S—C bonds, but showed a weak affinity on the pyrite surface.

Evaluation of the effect of pyrrolidine dithiocarbamate in suppressing inflammation in mice with dextran sodium sulfate-induced colitis

AIM: To evaluate the effect of pyrrolidine dithio- carbamate (PDTC; an NF-κB inhibitor) administered at low (50 mg/kg) and high (100 mg/kg) doses in suppressing colitis in mice with dextran sodium sulfate (DSS)-induced colitis. METHODS: Mice were divided into a DSS-untreated group (normal group), DSS-treated control group, DSS+PDTC-treated groupⅠ(low-dose group), and DSS+PDTC-treated groupⅡ (high-dose group). In each group, the disease activity index score (DAI score), intestinal length, histological score, and the levels of activated NF-κB and inflammatory cytokines (IL-1β and TNF-α) in tissue were measured. RESULTS: The DSS+PDTC-treated groupⅡ exhibited suppression of shortening of intestinal length and reduction of DAI score. Activated NF-κB level and IL-1β and TNF-α levels were significantly lower in DSS+PDTC- treated groupⅡ. CONCLUSION: These findings suggest that PDTC is useful for the treatment of ulcerative colitis.

Recent advances in fixation of CO_(2) into organic carbamates through multicomponent reaction strategies

Carbon dioxide(CO_(2)) is the main greenhouse gas and also an ideal C1 feedstock in organic synthesis because it is abundant,nontoxic,nonflammable,and renewable.The synthesis of organic carbamates using CO_(2) as a phosgene alternative has attracted extensive attention because of the importance of carbamates in organic synthesis and in the pharmaceutical and agrochemical industries.In recent decades,many multicomponent reaction strategies have been designed for constructing different types of organic carbamate molecules.Most of these methods rely on the in situ generation of carbamate anions from CO_(2) and amines,followed by reactions with other coupling partners.Synthetic strategies for acyclic carbamates include nucleophile‐electrophile coupling,nucleo‐phile‐nucleophile oxidative coupling,difunctionalization of unsaturated hydrocarbons,and C–H bond functionalization.Strategies for the synthesizing cyclic carbamates include carboxylative cyclization of in situ‐generated unsaturated amines and difunctionalization of unsaturated amines with CO_(2) and other electrophilic reagents.This review summarizes the recent advances in the synthesis of organic carbamates from CO_(2) using different multicomponent reaction strategies.Future perspectives and challenges in the incorporation of CO_(2) into carbamates are also presented.

CoFe_2O_4/CdS nanocomposite:Preparation,characterisation,and application in sonocatalytic degradation of organic dye pollutants

A magnetic CoFe2O4/Cd S nanocomposite was prepared via one-step hydrothermal decomposition of cadmium diethanoldithiocarbamate complex on the surface of CoFe2O4 nanoparticles at a low temperature of 200 ℃.The nanocomposite was characterised by X-ray diffraction（XRD）,Fourier transform infrared spectroscopy（FT-IR）,scanning electron microscopy,energy-dispersive X-ray spectroscopy（EDX）,UV-visible spectroscopy,transmission electron microscopy（TEM）,N2 gas sorption analysis,X-ray photoelectron spectroscopy（XPS）,and vibrating sample magnetometry.The FT-IR,XRD,EDX and XPS results confirmed the formation of the CoFe2O4/Cd S nanocomposite.Based on the TEM analysis,the CoFe2O4/Cd S nanocomposite constituted nearly uniform,sphere-like nanoparticles of ～20 nm in size.The optical absorption spectrum of the CoFe2O4/Cd S nanocomposite displayed a band gap of 2.21 e V,which made it a suitable candidate for application in sono/photocatalytic degradation of organic pollutants.Accordingly,the sonocatalytic activity of the CoFe2O4/Cd S nanocomposite was evaluated towards the H2O2-assisted degradation of methylene blue,rhodamine B,and methyl orange under ultrasonic irradiation.The nanocomposite displayed excellent sonocatalytic activity towards the degradation of all dyes examined—the dyes were completely decomposed within 5–9 min.Furthermore,a comparison study revealed that the CoFe2O4/Cd S nanocomposite is a more efficient sonocatalyst than pure Cd S;thus,adopting the nanocomposite approach is an excellent means to improve the sonoactivity of Cd S.Moreover,the magnetic properties displayed by the CoFe2O4/Cd S nanocomposite allow easy retrieval of the catalyst from the reaction mixture for subsequent uses.

Syntheses,Spectroscopic Properties and Crystal Structures of (2-Cl-C_6H_4CH_2)_3SnS_2CN(C_5H_(10)) and (2-Cl-C_6H_4CH_2)_3SnS_2CN(C_4H_9N)

Two tri(2-chlorobenzyl)tin(IV) complexes with dithiocarbamate ligands (2-Cl- C6H4CH2)3SnS2CN(C5H10) 1 and (2-Cl-C6H4CH2)3SnS2CN(C4H9N) 2 have been synthesized by the reaction of tri(2-chlorobenzyl)tin(IV) chloride with dithiocarbamates and characterized by elemental analysis, IR and 1H NMR. The crystal structures were determined by X-ray single-crystal diffraction. The crystal of complex 1 belongs to triclinic, space group P with a = 9.121(5), b = 10.788(6), c = 15.549(8) ? a = 77.812(6), b = 88.279(8), g = 72.023(6)o, Z = 2, V = 1421.5(13) ?, Dc = 1.532 g/cm3, ?= 1.344 mm-1, F(000) = 660, R = 0.0382 and wR = 0.0984; and that of complex 2 is of monoclinic, space group P21/n with a = 13.892(10), b = 2.1274(8), c = 2.0553(15) ? b = 107.145(11)o, Z = 4, V = 2726(3) ?, Dc = 1.600 g/cm3, ?= 1.403 mm-1, F(000) = 1320, R = 0.0361 and wR = 0.0826. Their structures show a distorted trigonal bipyramidal configuration with five- coordination for the central tin atoms.

Removal of nickel(Ⅱ) from aqueous solutions using iminodiacetic acid functionalized polyglycidyl methacrylate grafted-carbon fibers

Iminodiacetic acid functionalized polyglycidyl methacrylate grafted-carbon fibers(PGMA-IDA/CFs) were prepared for Ni(II) removal from aqueous solutions. The effects of solution p H value, temperature and adsorption time were investigated. The maximum adsorption capacity of Ni(II) on PGMA-IDA/CFs is 0.923 mmol·L-1· g-1at pH 5.2 and 50 °C. Kinetic data indicate that the adsorption process matches the pseudo-second-order model and Elovich kinetic model. Thermodynamic data suggest that the adsorption process is endothermic spontaneous reaction.

Synthesis of Toluene-2,4-Bisurea from 2,4-Toluene Diamine and Urea and the Reaction Kinetics

Toluene-2,4-bisurea (TBU) is an important intermediate for urea route to dimethyl toluene-2,4-dicarbamate and the study on TBU synthesis via the reaction of 2,4-toluene diamine (TDA) and urea is of great significance. Firstly, thermodynamic analysis shows that the reaction is exothermic and a high equilibrium conversion of TDA is expected due to its large reaction equilibrium constant. Secondly, under the suitable reaction conditions, 130 °C, 7 h, and molar ratio of TDA/zinc acetate/urea/sulfolane 1/0.05/3.5/10, TDA conversion is 54.3%, and TBU yield and selectivity are 39.8% and 73.3% respectively. Lastly, the synthesis of TBU is a 1st order reaction with respect to TDA and the reaction kinetics model is established. This work will provide useful information for commercializing the urea route to toluene-2,4-dicarbamate (TDC).

Effect of dosage of expandable graphite,dimethyl methylphosphonate,triethanolamine,and isocyanate on fluidity,mechanical,and flame retardant properties of polyurethane materials in coal reinforcement

In this study,orthogonal experiments were conducted to investigate the influence of expandable graphite(EG),dimethyl methylphosphonate(DMMP),triethanolamine(TEA),and isocyanate content on the compressive and bonding strengths,oxygen index,and fluidity of rigid polyurethane foam(RPUF).The results revealed that EG significantly increased the oxygen index of RPUF,enlarged the diameter of foam cells,and decreased the cell-closed content in foam;thus,leading to a pressure drop in RPUF.However,excessive EG was capable of reducing the fluidity of polyurethane slurry.TEA exhibited significant influence on the compressive strength of RPUF,which dropped initially,and then increased.DMMP had a remarkable effect on the flame retardant property and compressive strength of RPUF.Compressive strength of RPUF initially displayed an increase followed by a decrease with increasing dosage of DMMP,and achieved the maximum value at DMMP dosage of 4%.DMMP could effectively reduce the diameter of RPUF cells leading to an increase in the percentage of close area in foam.DMMP displayed the flame-retardation effects mainly in the gas phase leading to a significant enhancement in the oxygen index of RPUF.Moreover,the compressive strength and bonding strength of RPUF decrease significantly with the increase of isocyanate content due to the increased blowing efficiency by the CO_2.The oxygen index and flowing length of foam increased with the increase in isocyanate dosage.

Heterogeneous synthesis of dimethylhexane-1,6-dicarbamate from 1,6-hexanediamine and methyl carbonate in methanol over a CeO_2 catalyst

The efficient synthesis of dimethylhexane-1,6-dicarbamate(HDC)from 1,6-hexanediamine(HDA)and methyl carbonate over a series of heterogeneous catalysts(e.g.,Mg O,Fe2O3,Mo2O3,and Ce O2)was investigated.The reaction pathway was confirmed as an alcoholysis reaction through a series of designed experiments.Under optimized conditions,100%HDA conversion with 83.1%HDCtotaland 16.9%polyurea was obtained using a onestep with high temperature procedure with Ce O2as the catalyst.A new two-step with variable temperature technology was developed based on the reaction pathway to reduce the polyurea yield.Using the proposed method,the HDCtotalyield reached 95.2%,whereas the polyurea yield decreased to 4.8%.The Ce O2catalyst showed high stability and did not exhibit any observable decrease in the HDC yield or any structural changes after four recycling periods.

Preparation and Properties of Tung Oil-Based Polyurethane

Tung oil-based polyols were synthesized by the esterification and transesterification between Tung oilbased anhydride and butanediol. The hydroxyl values of the polyols prepared were tested and discussed. Polyurethane was prepared by using Tung oil-based polyols and/or poly(propylene glycol) as polyols and by using isophorone diisocyanate as isocyanate. The effect of the ratio of Tung oil-based polyols to poly(propylene glycol) on the properties of polyurethane prepared was investigated by the water resistance, alcohol resistance and hardness tests. The results show that Tung oil-based polyols are effective to improve the hardness, water resistance and alcohol resistance of polyurethane.

Impact of Soil Texture and Organic Matter Content on Methyl Isothiocyanate Volatilization from Soil Columns

Metam sodium （MS; sodium N-methyl dithiocarbamate） has emerged as a promising soil fumigant in the US to replace methyl bromide （MeBr）. Metam potassium （MK; potassium N-methyl dithiocarbamate） and MS break down into the volatile gas methyl isothiocyanate （MITC） to control soil borne pests. Many studies have focused on MS, but MK has not been studied as thoroughly. The objective of this research was to determine the effect of increasing organic matter （OM） treatments and soil texture to minimize the off-gassing of MS and MK. Bench-scale soil column studies were performed to simulate organic matter treatments that may decrease the volatilization loss of MITC. Incorporation depth of OM simulated surface tillage （0-15 cm） practices. Soil was packed in steel columns and MS or MK was applied at a depth of 15 cm and MITC volatilization was measured using gas chromatography/mass spectroscopy. Volatilization of MITC behaved similarly for MS and MK with MITC movement impacted by soil texture. MITC volatilization was lower from a sandy clay loam than a sandy soil. Surface incorporation of OM did not significantly decrease MITC volatilization. These results suggest that soil texture is the dominant factor reducing MITC off-gassing and prolonging the time needed to control soil borne pests.

Discovery of novel dithiocarbamic acid ester HGWJ-11C with significant anticancer action

To find novel lead compound, seventy-four compound libraries were built through two rounds by a solution-phase CC on the basis of our developed method for the synthesis of dithiocarbamic acid ester. After evaluation for the antitumor activities of libraries, six compounds were selected to be synthesized and examined their antitumor activities. It was found that compound 13 （HGWJ-11 C） with novel structure exhibited significant antitumor activities and the scaffold of dithiocarbamic acid was very crucial for the antitumor activity. The compound 13 is worth studying deeply as a potent hit compound.

Effects of compound 209 on colorectal cancer cell HT-29 in vivo and in vitro

Compound 209 is a newly synthesized dithiocarbamate derivative with antiproliferation activity in vitro, however, its antitumor effect in vivo and the underlying mechanisms have yet to be identified. We explored the antitumor effect of compound 209 and the possible mechanisms for its inhibition of the growth of HT-29 xenograff tumor and proliferation of HT-29 cells. Cell proliferation was evaluated with SRB assay in vitro. The results showed that compound 209 had significant antiproliferation activity on HT-29 cells. Furthermore, the xenograff HT-29 nude mouse model was used to study the antitumor effect of compound 209 in vivo. We found that compound 209 significantly inhibited tumor growth and did not cause loss of body weight or leukocytopenia. Analysis by flow cytometry indicated that compound 209 arrested HT-29 cell cycle in G~ phase. Western blotting analysis suggested that compound 209 increased the expression of p27, cyclin E, CDK2, cyclin D1 and CDK4. These results demonstrated the antitumor effect of compound 209 and its potential use as an anticancer drug.

IC5, a dithiocarbamate derivative, inhibits colon cancer cell proliferation in vitro and colitis-associated colorectal carcinogenesis in vivo

Colorectal cancer （CRC） is one of the leading causes of cancer-related deaths, and inflammatory bowel diseases and dysregulated cell proliferation play important roles in colorectal carcinogenesis. Therefore, inhibition of inflammatory signaling and cell proliferation is used as a major strategy for chemoprevention of CRC. In the present study, it was found that IC5, a dithiocarbamate derivative, could inhibit the proliferation of LoVo human colon cancer cells in a concentration-dependent manner, with an IC50 of 22 gM. The anti-proliferation effect of IC5 was accompanied by a significant cell cycle arrest in G2/M phase. Further study revealed that IC5 significantly inhibited NF-~B signaling in LoVo cells, suggesting that IC5 could inhibit inflammatory responses. We then evaluated the in vivo efficacy of IC5 to inhibit colitis-associated colorectal carcinogenesis using an azoxymethane （AOM）/dextran sodium sulfate （DSS） mouse model. AOM/DSS treatment resulted in a CRC incidence of 58.3%, while the incidences were decreased to 37.5% and 25% in mice orally administered with 50 and 100 mg/kg IC5, respectively. In addition, IC5 also reduced the plasma levels of alanine aminotransferase and asparatate aminotransferase. Taken together, these results suggested that IC5 could prevent colitis-associated colorectal carcinogenesis, and more attention should be paid to it as a cancer chemopreventive agent in further investigation.

Enhanced antitumor effect of TM208 in combination with 5-fluorouracil in H_(22) transplanted mice

4-Methylpiperazine-l-carbodithioc-acid-3-cyano-3,3-diphenylpropyl ester hydrochloride（TM208）,a newly synthesized dithiocarbamate derivative,exhibits antitumor effect in vivo with low toxicity.However,the antitumor effect of TM208 in combination with drugs in clinical use for cytotoxic chemotherapy has not been identified.In our study,the antitumor effects and toxicities of TM208 in combination with cisplatin（DDP）,cyclophosphamide（CTX） and 5-fluorouracil（5-Fu）,respectively,were evaluated in vivo using a transplanted solid-type hepatocarcinoma H_（22） mice model.The results suggested that 5-Fu（5 mg/kg/2d） potentiated the antitumor effect of TM208（100 mg/kg/d） with significantly higher tumor inhibition rates（P0.01） and a slight elevation of toxicity;however,DDP and CTX in combination with TM208 did not exhibit similar enhanced antitumor effect.For further investigation,we found that the TM208 and 5-Fu combination therapy led to G_2/M cell cycle arrest of tumor cells in vivo by downregulating the protein expression of cyclin Bl,cdc2,cdk7,and upregulating the expression of p21 and p53.The protein expression levels of cyclin Dl and cyclin E were also downregulated in tumor cells treated with TM208 and 5-Fu,while those of cdk4 and cdk2 remained unchanged.The change of mRNA expression level of cdc2 was consistent with that of its protein in each group,while the mRNA expression of cyclin B1 remained unchanged among each group.These results demonstrated the dosage regimen of TM208 for combination therapy and could serve as evidence for clinical use of TM208 as an antineoplastic drug.

The pharmacological mechanism underlying the apoptosis of human hepatic stellate cells LX-2 induced by NF-κB inhibitor PDTC

In the present study,we aimed to confirm whether NF-κB inhibitor pyrrolidine dithiocarbamate(PDTC)could induce apoptosis of human hepatic stellate cells(HSCs)LX-2 and explore the potential pharmacological mechanism underlying these effects.In this study,LX-2 cells were cultured in vitro,and the experiment was divided into two groups,including the control and PDTC groups.The viability of LX-2 cells was measured by CCK8 assay after the cells were exposed to PDTC.The anti-apoptotic effect of PDTC was detected by AO/EB double assay staining kit.Additionally,the activities of NF-κB,Fas/FasL,apoptosis-related proteins,as well as the cellular localization of AIF,were determined by Western blotting analysis and immunofluorescence staining respectively.After PDTC treatment for 12 and 24 h,AO/EB dual staining showed typical apoptotic changes,such as cell volume reduction,cell shrinkage,nuclear fragmentation,and so on.PDTC at 60μmol/L significantly increased the proliferation inhibition rate and decreased the secretion of collagen I,collagen III,andα-SMA in LX-2 cells.The Western blotting analysis and RT-PCR showed no significant difference in the expression of AIF between the control group and PDTC group,and the expressions of Fas and FasL were not observed in all groups(P>0.05).Further results showed that PDTC could promote the displacement of AIF from mitochondria to the nucleus,activate the apoptotic signaling in the cell nucleus,and possibly participate in the apoptosis process of LX-2 cells.In conclusion,the pharmacological mechanism of PDTC against hepatic fibrosis might be to promote the displacement of AIF from mitochondria to the nucleus,then activate the apoptotic signaling in the cell nucleus,and finally induce the apoptosis of LX-2 cells.Meanwhile,these results also revealed that the Fas/FasL-mediated apoptosis pathway was not involved in the PDTC-induced apoptosis process of LX-2 cells.