The methanol extract form the leaves of Phytolacca icosandra L.,afforded the unprecedented artificial triterpenoid fatty acid ester 1 derived from the new natural triterpenoid phytolaccagenic acid 3-O-myristate(1a),al...The methanol extract form the leaves of Phytolacca icosandra L.,afforded the unprecedented artificial triterpenoid fatty acid ester 1 derived from the new natural triterpenoid phytolaccagenic acid 3-O-myristate(1a),along with the three known triterpenoids serjanic,acinosolic and phytolaccagenic acid(2-4).Their structures were stablished by HR-EI-MS,1D and 2D NMR techniques.The possible mechanistic formation of 1 is proposed,and the in vitro toxicity of all compounds was assessed using the brine shrimp lethality assay(BSLA).展开更多
The fatty acid profile in breast milk of nursing mothers who participated in a Cohort for Vitamin A (COVA) study at the fourth and ninth month of lactation was investigated. Breast milk samples were collected by manua...The fatty acid profile in breast milk of nursing mothers who participated in a Cohort for Vitamin A (COVA) study at the fourth and ninth month of lactation was investigated. Breast milk samples were collected by manual expression and stored at - 20°C until analysis. The fat was extracted from the milk and methylated using the American Oil Chemists’ Society (AOCS) Official Methods with modifications. The separation, identification and quantification of the fatty acid methyl esters was performed by gas chromatography coupled with mass spectrometry (GC-MS). Fat contents of human milk increased significantly between the fourth and ninth month of lactation 0.38 and 1.21 mg·mL<sup>-1</sup> respectively;P 0.05) than the average percent of the total unsaturated FAs (48.93%). Similarly, at the 9th month the percentage average of the total saturated fatty acids (15.18%) was significantly lower (P < 0.05) than the average percent of the total unsaturated FAs (31.05%). The results obtained in this study demonstrated that the fat content in breast milk significantly increased in the 9th compared to the 4th month of lactation. The fatty profile was also significantly different with the omega 6 being the dominant at the 9th month compared with the omega - 9 being dominant at the 4th month of lactation.展开更多
The evaporation characteristics of fatty acid methyl ester(FAME)mixed with four concentrations of ethanol at 873 K and normal atmospheric pressure are studied herein.FAME is used as base oils,and et hanol mass fractio...The evaporation characteristics of fatty acid methyl ester(FAME)mixed with four concentrations of ethanol at 873 K and normal atmospheric pressure are studied herein.FAME is used as base oils,and et hanol mass fractions vary from 10%,20%,30%to 40%。The experimental results show that the evaporation process of the binary component droplets of FAME-ethanol can be divided into two stages:a fuctuation evaporation stage,and an equilibrium evaporation stage.In these four concentration gradients,micro-explosions occur in the droplet evaporation process.The fuctuation evaporation stage is divided into two stages:a strong fuctuation stage and a weak fluctuation stage.After the micro-explosion,there is still a small amount of ethanol in the droplet.Due to the surface tension of the droplet,a small amount of ethanol cannot make the droplet violently fuctuate.The results show that the earlier the droplet micro-explosion occurs,the more intense it is,and the shorter the lifetime of the droplet is.Different concentrations of ethanol have different improvements in droplet evaporation characteristics.Generally,the higher the ethanol concentration is,the shorter the lifetime of the droplet is.However,increasing the ethanol concentration from 20%to 30%has the most obvious effect on the lifetime of the droplet.展开更多
This article reports a high yielding technique of synthesizing zirconium dodecyl sulphate (“ZDS”) for in situ transesterification of Nannochloropsis occulata and Chlorella vulgaris for fatty acid methyl ester (FAME)...This article reports a high yielding technique of synthesizing zirconium dodecyl sulphate (“ZDS”) for in situ transesterification of Nannochloropsis occulata and Chlorella vulgaris for fatty acid methyl ester (FAME) production. ZDS produced a significantly higher FAME yield in N. occulata than in C. vulgaris (p = 0.008). The varying performance of ZDS in the two species could be due to their different cell wall chemistries. Sodium dodecyl sulphate (SDS) in H2SO4 for FAME enhancement from the two species was also studied. Treatment with SDS in H2SO4 increased the FAME production rate in both species. Residual protein content after the in situ transesterification in C. vulgaris and N. occulata reduced respectively by 6.5% and 10%. The carbohydrate content was reduced by 71% in C. vulgaris and 65% in N. occulata. The water tolerance of the process when using H2SO4, with or without SDS, was evaluated by hydrating the two species with 10% - 30% distilled water (w/w dry algae). The FAME concentration began to diminish only at 30% water content in both species. Furthermore, the presence of a small amount of water in the biomass or methanol increased the lipid extraction efficiency, improving the FAME yield, rather than inhibiting the reaction.展开更多
Processing polyvinyl chloride(PVC)artificial material requires plasticizer that softens the PVC coating.Currently,utilizing unsaturated fatty acid methyl esters to obtain epoxidized fatty acid methyl ester(EFAME)bio-p...Processing polyvinyl chloride(PVC)artificial material requires plasticizer that softens the PVC coating.Currently,utilizing unsaturated fatty acid methyl esters to obtain epoxidized fatty acid methyl ester(EFAME)bio-plasticizers constitutes an environmentally responsible solution to substitute conventional ortho-phthalates that are endocrine disruptors or probable carcinogens.However,commercial EFAMEs,even with the highest epoxy value(ca.5.5-5.8%)so far,still suffer from fast leaching from the PVC matrix,burdening the environment and shortening lifespan of the artificial material.Here,we report a proof-of-principle demonstration of a new strategy to obtain migration-resistant EFAME that harnesses the midchain hydroxyl of methyl ricinoleate and covalently attachment of a pendant acetate ester.Despite a low epoxy value(3.0%),the engineered bio-plasticizer displays significantly suppressed migration in multiple scenarios compared with one conventional EFAME with much higher epoxy value(5.8%).Circumventing the limit confronting previous strategy that highlights the sole contribution of epoxy value to achievable migration resistance,the rationale herein may provide guidance for designing new EFAMEs with comparable performance to ortho-phthalates,thus bringing the old and oft-maligned PVC artificial material industry one step closer to sustainability.展开更多
As an imitation of genuine leather,polyvinyl chloride(PVC)artificial materials are versatile,but suffers from being flammable due to the presence of large amounts of combustible plasticizers.Under such circumstance,in...As an imitation of genuine leather,polyvinyl chloride(PVC)artificial materials are versatile,but suffers from being flammable due to the presence of large amounts of combustible plasticizers.Under such circumstance,intrinsically flame-retardant plasticizers displaying dual functions have been a subject of intensive research interest.However,previous strategies attempting to covalently attach flame-retardant moiety to plasticizers invariably required either expensive starting materials or laborious and tedious procedures,ultimately limiting their scale-up application in industry.In addition,driven by escalating demand of halogen-free flame retardants worldwide from an environmental health perspective,previously reported intrinsically flame-retardant plasticizers were mainly halogenfree,less attractive in PVC artificial material industry simply because PVC itself is a halogen-containing polymer.Here,we report an approach to introduce chlorine moieties into unsaturated fatty acid methyl ester by a simple addition reaction occurring on carbon-carbon double bonds,yielding a chlorine-containing,intrinsically flameretardant bio-plasticizer.When combined with di-(2-ethylhexyl)phthalate(DOP)in PVC formulations,the chlorinated fatty acid methyl ester is qualified as a co-plasticizer while conferring flame retardancy upon the PVC coatings.This approach involves only a one-step procedure that employs renewable fatty acid methyl esters and cheap chlorine gas as raw materials,thus being of great potential to enable intrinsically flame-retardant bioplasticizers on a large scale to manufacture functional PVC artificial materials for application in fire-prone scenarios.展开更多
基金The authors would like to thank USB-DID(project S1-IC-CB-004–15)for financial support。
文摘The methanol extract form the leaves of Phytolacca icosandra L.,afforded the unprecedented artificial triterpenoid fatty acid ester 1 derived from the new natural triterpenoid phytolaccagenic acid 3-O-myristate(1a),along with the three known triterpenoids serjanic,acinosolic and phytolaccagenic acid(2-4).Their structures were stablished by HR-EI-MS,1D and 2D NMR techniques.The possible mechanistic formation of 1 is proposed,and the in vitro toxicity of all compounds was assessed using the brine shrimp lethality assay(BSLA).
文摘The fatty acid profile in breast milk of nursing mothers who participated in a Cohort for Vitamin A (COVA) study at the fourth and ninth month of lactation was investigated. Breast milk samples were collected by manual expression and stored at - 20°C until analysis. The fat was extracted from the milk and methylated using the American Oil Chemists’ Society (AOCS) Official Methods with modifications. The separation, identification and quantification of the fatty acid methyl esters was performed by gas chromatography coupled with mass spectrometry (GC-MS). Fat contents of human milk increased significantly between the fourth and ninth month of lactation 0.38 and 1.21 mg·mL<sup>-1</sup> respectively;P 0.05) than the average percent of the total unsaturated FAs (48.93%). Similarly, at the 9th month the percentage average of the total saturated fatty acids (15.18%) was significantly lower (P < 0.05) than the average percent of the total unsaturated FAs (31.05%). The results obtained in this study demonstrated that the fat content in breast milk significantly increased in the 9th compared to the 4th month of lactation. The fatty profile was also significantly different with the omega 6 being the dominant at the 9th month compared with the omega - 9 being dominant at the 4th month of lactation.
基金the Foundation Research Project of Jiangsu Province(the Natural Science Fund,No.BK20180982)。
文摘The evaporation characteristics of fatty acid methyl ester(FAME)mixed with four concentrations of ethanol at 873 K and normal atmospheric pressure are studied herein.FAME is used as base oils,and et hanol mass fractions vary from 10%,20%,30%to 40%。The experimental results show that the evaporation process of the binary component droplets of FAME-ethanol can be divided into two stages:a fuctuation evaporation stage,and an equilibrium evaporation stage.In these four concentration gradients,micro-explosions occur in the droplet evaporation process.The fuctuation evaporation stage is divided into two stages:a strong fuctuation stage and a weak fluctuation stage.After the micro-explosion,there is still a small amount of ethanol in the droplet.Due to the surface tension of the droplet,a small amount of ethanol cannot make the droplet violently fuctuate.The results show that the earlier the droplet micro-explosion occurs,the more intense it is,and the shorter the lifetime of the droplet is.Different concentrations of ethanol have different improvements in droplet evaporation characteristics.Generally,the higher the ethanol concentration is,the shorter the lifetime of the droplet is.However,increasing the ethanol concentration from 20%to 30%has the most obvious effect on the lifetime of the droplet.
文摘This article reports a high yielding technique of synthesizing zirconium dodecyl sulphate (“ZDS”) for in situ transesterification of Nannochloropsis occulata and Chlorella vulgaris for fatty acid methyl ester (FAME) production. ZDS produced a significantly higher FAME yield in N. occulata than in C. vulgaris (p = 0.008). The varying performance of ZDS in the two species could be due to their different cell wall chemistries. Sodium dodecyl sulphate (SDS) in H2SO4 for FAME enhancement from the two species was also studied. Treatment with SDS in H2SO4 increased the FAME production rate in both species. Residual protein content after the in situ transesterification in C. vulgaris and N. occulata reduced respectively by 6.5% and 10%. The carbohydrate content was reduced by 71% in C. vulgaris and 65% in N. occulata. The water tolerance of the process when using H2SO4, with or without SDS, was evaluated by hydrating the two species with 10% - 30% distilled water (w/w dry algae). The FAME concentration began to diminish only at 30% water content in both species. Furthermore, the presence of a small amount of water in the biomass or methanol increased the lipid extraction efficiency, improving the FAME yield, rather than inhibiting the reaction.
基金financial support of this work by National Key Research and Development Program of China(2017YFB0308600)National Natural Science Foundation of China(21878196)Fundamental Research Funds for the Central Universities,China(20826041C4159).
文摘Processing polyvinyl chloride(PVC)artificial material requires plasticizer that softens the PVC coating.Currently,utilizing unsaturated fatty acid methyl esters to obtain epoxidized fatty acid methyl ester(EFAME)bio-plasticizers constitutes an environmentally responsible solution to substitute conventional ortho-phthalates that are endocrine disruptors or probable carcinogens.However,commercial EFAMEs,even with the highest epoxy value(ca.5.5-5.8%)so far,still suffer from fast leaching from the PVC matrix,burdening the environment and shortening lifespan of the artificial material.Here,we report a proof-of-principle demonstration of a new strategy to obtain migration-resistant EFAME that harnesses the midchain hydroxyl of methyl ricinoleate and covalently attachment of a pendant acetate ester.Despite a low epoxy value(3.0%),the engineered bio-plasticizer displays significantly suppressed migration in multiple scenarios compared with one conventional EFAME with much higher epoxy value(5.8%).Circumventing the limit confronting previous strategy that highlights the sole contribution of epoxy value to achievable migration resistance,the rationale herein may provide guidance for designing new EFAMEs with comparable performance to ortho-phthalates,thus bringing the old and oft-maligned PVC artificial material industry one step closer to sustainability.
基金financial support of this work by National Key Research and Development Program of China(2017YFB0308600)Science and Technology Planning Project of Sichuan Province(20YYJC3727)+1 种基金National Natural Science Foundation of China(21878196)Fundamental Research Funds for the Central Universities,China(20826041C4159).
文摘As an imitation of genuine leather,polyvinyl chloride(PVC)artificial materials are versatile,but suffers from being flammable due to the presence of large amounts of combustible plasticizers.Under such circumstance,intrinsically flame-retardant plasticizers displaying dual functions have been a subject of intensive research interest.However,previous strategies attempting to covalently attach flame-retardant moiety to plasticizers invariably required either expensive starting materials or laborious and tedious procedures,ultimately limiting their scale-up application in industry.In addition,driven by escalating demand of halogen-free flame retardants worldwide from an environmental health perspective,previously reported intrinsically flame-retardant plasticizers were mainly halogenfree,less attractive in PVC artificial material industry simply because PVC itself is a halogen-containing polymer.Here,we report an approach to introduce chlorine moieties into unsaturated fatty acid methyl ester by a simple addition reaction occurring on carbon-carbon double bonds,yielding a chlorine-containing,intrinsically flameretardant bio-plasticizer.When combined with di-(2-ethylhexyl)phthalate(DOP)in PVC formulations,the chlorinated fatty acid methyl ester is qualified as a co-plasticizer while conferring flame retardancy upon the PVC coatings.This approach involves only a one-step procedure that employs renewable fatty acid methyl esters and cheap chlorine gas as raw materials,thus being of great potential to enable intrinsically flame-retardant bioplasticizers on a large scale to manufacture functional PVC artificial materials for application in fire-prone scenarios.