[Objective] The study aimed to investigate the changes of water status and different responses of osmoregulants during air-drought stress,to better understand mechanisms of drought resistance in Jatropha Curcas L. [Me...[Objective] The study aimed to investigate the changes of water status and different responses of osmoregulants during air-drought stress,to better understand mechanisms of drought resistance in Jatropha Curcas L. [Methods] The 12-day-old J. curcas seedlings were held in a climate chamber at 25/20 ℃(day/night),16 hours illumination,and 75% of relative humidity for air-drought treatment,and the changes of water potential,osmotic potential and the content of soluble sugar,proline,betaine were measured. [Results] Water potential and osmotic potential in leaves of J. curcas seedlings dropped significantly,pressure potential lost during air-drought stress,and the contents of osmoregulants soluble sugar,proline and betaine rose significantly to different extent in the leaves and stems. [Conclusion] Osmoregulants in the leaves and stems respond differently to air-drought stress,and in general leaves are much more responsive to the drought than stems of J. curcas seedlings.展开更多
Yunnan Province is the main distributing area ofJatropha curcas L. This plant is abundant in several drainage areas of the dry-hot, dry-warm and sub-humid valleys in the south subtropical area of Yunnan Province. The ...Yunnan Province is the main distributing area ofJatropha curcas L. This plant is abundant in several drainage areas of the dry-hot, dry-warm and sub-humid valleys in the south subtropical area of Yunnan Province. The seeds that were picked from trees blossoming between April and May and fructifying between September and October will have large seed yield and fine quality. For developing bio-diesel stock forest ofJ. curcas in areas with adaptive climate, seeding measures for afforestation should be taken and techniques on breeding, fast-growing, and high-yielding plantation cultivation are very important.展开更多
In recent years, Jatropha curcas L. has gained popularity as a potential biodiesel plant. The varying oil content, reported between accessions belonging to different agroclimatic zones, has necessitated the assessment...In recent years, Jatropha curcas L. has gained popularity as a potential biodiesel plant. The varying oil content, reported between accessions belonging to different agroclimatic zones, has necessitated the assessment of the existing genetic variability to generate reliable molecular markers for selection of high oil yielding variety. EST derived SSR markers are more useful than genomic markers as they represent the transcriptome, thus, directly linked to functional genes. The present report describes the in silico mining of the microsatellites (SSRs) using J. curcas ESTs from various tissues viz. embryo, root, leaf and seed available in the public domain of NCBI. A total of 13,513 ESTs were downloaded. From these ESTs, 7552 unigenes were obtained and 395 SSRs were generated from 377 SSR-ESTs. These EST-SSRs can be used as potential microsatellite markers for diversity analysis, MAS etc. Since the Jatropha genes carrying SSRs have been identified in this study, thus, EST-SSRs directly linked to genes will be useful for developing trait linked markers.展开更多
In recent years Jatropha curcas L. has emerged as a biofuel crop with potential for its production in marginal land with application of treated sewage water. Since this is a new crop for its profitable cultivation, ad...In recent years Jatropha curcas L. has emerged as a biofuel crop with potential for its production in marginal land with application of treated sewage water. Since this is a new crop for its profitable cultivation, additional research is needed to develop optimal management programs, including macro and micronutrients applications. A pot experiment was conducted in a Greenhouse at the National Research Center, Dokki, Cairo, Egypt, during 2010 summer to evaluate effects of varying concentrations of iron (Fe), manganese (Mn), and zinc (Zn) in irrigation water (0, 50, 100, 150, 200 and 250 ppm) on the growth, biomass production, photosynthetic pigments, and mineral nutrients status in the plants. Increasing concentrations of Fe, Mn, and Zn in irrigation water up to 150 ppm increased the biomass weight, photosynthetic pigments, and nutrient uptake by Jatropha plants. Further increase in concentrations of micronutrients showed negative effects on the above response parameters. Therefore, this study demonstrates that Jatropha can be grown under irrigation using waste water containing reasonable concentrations of micronutrients and heavy metals. This property of Jatropha provides some support for potential use of this crop for phytoremediation of metal contaminated soils. However, long term field research is needed to further verify both the above beneficial effects.展开更多
During the last decade, Jatropha curcas L. (J. curcas) has gained much attention worldwide as biofuel crop. Although its cultivation is promoted in the Sahel, there is a surprising lack of data on its water use regula...During the last decade, Jatropha curcas L. (J. curcas) has gained much attention worldwide as biofuel crop. Although its cultivation is promoted in the Sahel, there is a surprising lack of data on its water use regulation and growth in this region. Here, we investigated, in semi-controlled conditions, leaf transpiration and growth of six accessions of J. curcas at seedling stage under natural changing in vapour pressure deficit (VPD) and progressive soil drying in Senegal. The experimental layout was a randomized complete bloc design and after 3 months of growth arranged to a split-plot at the implementation of water stress to facilitate irrigation. Under well water condition, there was no significant difference between accessions for leave transpiration that was positively correlated to VPD with high values recorded between 13 h and 14 h pm. Accessions of J. curcas used in this study showed closed thresholds at which transpiration declined except accession from Ndawene that threshold was lower (0.30). There is no significant difference between accessions for growth during the experimentation period. In 3 months, we recorded 23.57 g for the aboveground dry biomass and seedlings had about 14 leaves and 24.3 cm height. Positive linear correlation was recorded between aboveground biomass and root dry weight (p J. curcas might need complement irrigation for a better growth of seedlings especially during the dry season.展开更多
Biodiesel, which is a renewable and environmentally friendly fuel, has been studied widely to help remedy increasing environmental problems. One of the key processes of biodiesel production is oil extraction from oils...Biodiesel, which is a renewable and environmentally friendly fuel, has been studied widely to help remedy increasing environmental problems. One of the key processes of biodiesel production is oil extraction from oilseed materials. Switchable solvents can reversibly change from molecular to ionic solvents under atmospheric CO_2,and can be used for oil extraction. N, N-dimethylcyclohexylamine(DMCHA), a switchable solvent, was used to extract oil from Jatropha curcas L. oil seeds to produce biodiesel. The appropriate extraction conditions were:1:2 ratio of seed mass to DMCHA volume, 0.3–1 mm particle size, 200 r·min-1agitation speed, 60 min extraction time, and 30 °C extraction temperature. The extraction ratio was about 83%. This solvent extracted the oil more efficiently than hexane, and is much less volatile. By bubbling CO_2 under 1 atm and 25 °C for 5 h, the oil was separated, and DMCHA was recovered after releasing CO_2 by bubbling N_2 under 1 atm and 60 °C for 2 h. The residual solvent content in oil was about 1.7%. Selectivity of DMCHA was evaluated by detecting the protein and sugar content in oil. Using the oil with residual solvent to conduct transesterification process, the oil conversion ratio was approximately 99.5%.展开更多
An environmentally benign process was devel-oped for the transesterification of Jatropha curcas L. seed oil with methanol using artificial zeolites loaded with potassium acetate as a heterogeneous catalyst. After calc...An environmentally benign process was devel-oped for the transesterification of Jatropha curcas L. seed oil with methanol using artificial zeolites loaded with potassium acetate as a heterogeneous catalyst. After calcination for 5 h at 823 K, the catalyst loaded with 47 wt.% CH3COOK exhibited the highest efficiency and best catalytic activity. The easily prepared cata-lysts were characterized by means of X-ray dif-fraction and IR spectroscopy, as well as Hammett indicator titration. The results revealed a strong dependence of catalytic activity on ba-sicity. The optimum reaction conditions for transesterification of J. curcas oil were also in-vestigated. The methyl ester content in the bio-diesel product exceeded 91% after 4h reaction at reflux temperature in the presence of 2% solid catalyst and no water washing process is needed during workup.展开更多
Biodiesel produced from crude Jatropha curcas L.oil with trace sulfuric acid catalyst(0.02%-0.08% oil) was investigated at 135-184 ℃.Both esterification and transesterification can be well carried out simultane-ously...Biodiesel produced from crude Jatropha curcas L.oil with trace sulfuric acid catalyst(0.02%-0.08% oil) was investigated at 135-184 ℃.Both esterification and transesterification can be well carried out simultane-ously.Factors affecting the process were investigated,which included the reaction temperature,reaction time,the molar ratio of alcohol to oil,catalyst amount,water content,free fatty acid(FFA) and fatty acid methyl ester(FAME) content.Under the conditions at 165 ℃,0.06%(by mass) H2SO4 of the oil mass,1.6 MPa and 20:1 methanol/oil ratio,the yield of glycerol reached 84.8% in 2 hours.FFA and FAME showed positive effect on the transesterification in certain extent.The water mass content below 1.0% did not show a noticeable effect on trans-esterification.Reaction kinetics in the range of 155 ℃ to 175 ℃ was also measured.展开更多
Jatropha curcas L. (JCL) seeds were extracted and transesterified in-situ using supercritical methanol extraction in the absence of catalyst at different temperatures (200-280℃) and pressures (8-12 MPa), and at...Jatropha curcas L. (JCL) seeds were extracted and transesterified in-situ using supercritical methanol extraction in the absence of catalyst at different temperatures (200-280℃) and pressures (8-12 MPa), and at a fixed reaction time of 30 min with seeds-to-methanol ratio of 1:40 w/v. Design of experiment approach using five-level-two-factors design of Response Surface Methodology (RSM) was used to observe the effect of two independent variables i.e. temperature and pressure and the percent of biodiesel yield which required 13 runs. For optimization of the variables, Central Composite Rotatable Design (CCRD) was used for regression analysis and analysis of variance (ANOVA). The optimize conditions suggested by RSM were at T = 280℃ and P = 12.04 MPa. The predicted and experimental biodicsel yields were found to be 56.8% and 59.9%, respectively, with relatively small deviation errors of 1.59%.展开更多
Objective To clone the ACP(acyl carrier protein)gene in Jatropha curcas L.,a potential anti-tumour and anti-fungal plant.And to determinate the expression of ACP in Jatropha curcas L.Methods A cDNA clone encoding ACP(...Objective To clone the ACP(acyl carrier protein)gene in Jatropha curcas L.,a potential anti-tumour and anti-fungal plant.And to determinate the expression of ACP in Jatropha curcas L.Methods A cDNA clone encoding ACP(acyl carrier protein)was isolated from Jatropha curcas L.endosperm cDNA library by random sequencing.The expression of ACP gene was investigated by semi-quantitative RT-PCR in leaves,stems and seeds of J.curca.The expression of ACP was also investigated in germinating seeds.The fragment encoding ACP protein in J.curca.was inserted into a prokaryotic expression vector pET28a(+).The gene was overexpressed in E.coli BL21 to produce abundant protein.Immunohistochemical analysis was used to detect the expression of ACP in different tissues of J.curca.Results The cDNA sequence was 806 bp in length and the ORF was 393 bp.The predicted molecular weight of the putative protein was 14.4 kD,pI=5.2.It contained a 4'-phosphopantetheine-binding motif.This prosthetic group can be combined with Serine of ACP protein.Semi-quantitative RT-PCR analysis showed that ACP gene was expressed in leaves,stems and seeds of J.curcas.The expression level of ACP was the highest in seeds and it was not detected in roots.After seeds germinated,the expression level of ACP in seeds increased progressively and reached a peak at 96 h.After induced by IPTG,SDS-PAGE analysis showed that the ACP protein of 20 kD was expressed.Immunohistochemical analysis showed that ACP specifical expressed abundantly in embyo of the seeds,and it was not detected in roots and the emdosperm while expressed in leaves and stems.Conclusions A cDNA clone encoding ACP which had all the typical characteristics of ACPs was isolated.It was expressed successfully in E.coli.The results of semi-quantitative RT-PCR analysis and immunohistochemical analysis were very similar,which showed that the expression of ACP in J.curcas.was abundant in seeds.The results indicated the expression related to the high metabolism.展开更多
In this study, the methanolysis of mixed crop oils (Hevea brasiliensis and Jatropha curcas L.) was investigated. Due to the oils contain high impurities, a particular pre-treatment of which was carried out. For alkali...In this study, the methanolysis of mixed crop oils (Hevea brasiliensis and Jatropha curcas L.) was investigated. Due to the oils contain high impurities, a particular pre-treatment of which was carried out. For alkali-catalyzed methanolysis, few parameters (such as: molar ratio, catalyst percentage, and reaction time) were studied. The results showed that the methanolysis optimum conditions were 5.5 of molar ratio, 0.9% w/w of catalyst, and 60 minutes of reaction time with the highest yield of 98.9%. The kinetics study indicated that first order reaction mechanism with reaction rate constant and activation energy were 1.5 × 10-2 minute-1 and 23.93 KJ?mol-1 respectively. As fuel, the physicochemical properties of biodiesel met the standard values required by ASTM D6751.展开更多
Background:Diabetes mellitus is a chronic metabolic disease that is a risk factor for epidemic pathologies.Under hyperglycemic conditions,the enzyme aldose reductase catalyzes the formation of sorbitol in the metaboli...Background:Diabetes mellitus is a chronic metabolic disease that is a risk factor for epidemic pathologies.Under hyperglycemic conditions,the enzyme aldose reductase catalyzes the formation of sorbitol in the metabolism of glucose via polyols,leading to the development of diabetic complications.Therefore,inhibitors of this enzyme are therapeutic targets for the prophylaxis and treatment of these conditions.Methods:In this study,a generalized linear regression model was developed to analyze flavonoids-obtained from a database-that have been tested as inhibitors of aldose reductase.In this sense,the molecular descriptors implemented in DRAGON and MATLAB software were used to determine the correlation between the chemical structure of the inhibitors and their pharmacological activity.The model was validated according to the Organisation for Economic Co-operation and Development Standards and subsequently used for the virtual screening of the flavonoids identified in Jatropha gossypiifolia L.Results:The proposed model showed a good fit for its statistical parameters(R2=0.95).In addition,it showed good predictive power(R2 ext=0.94)and robustness(Q2 LOO=0.92).The experimental chemical space wherein the predictions were reliable(domain of application)was also defined.Finally,the model was used to identify 10 flavonoids from Jatropha gossypiifolia L.as candidates for natural drugs.Compounds with a low probability of oral absorption were identified,among which the elagic acid biflavonoid showed the greatest promise(pIC50 predicted=9.75).Conclusion:The Jatropha gossypiifolia L.species harbors flavonoids with high potential as inhibitors of the aldose reductase enzyme,in which the biflavonoid ellagic acid was shown to be the most promising inhibitor of the aldose reductase enzyme,suggesting its possible use in the treatment of the late complications of diabetes mellitus.展开更多
In this study, a simple and effective technique for establishing an external mass transfer model in a recirculated packed-bed batch reactor (RPBBR) with an immobilized lipase enzyme and Jatropha oil system is presente...In this study, a simple and effective technique for establishing an external mass transfer model in a recirculated packed-bed batch reactor (RPBBR) with an immobilized lipase enzyme and Jatropha oil system is presented. The external mass transfer effect can be represented with a model in the form of Colburn factor JD = K Re-(1–n). The value of K and n were derived from experimental data at different mass flow rates.The experiment shows an average increment of 1.51% FFA for calcium alginate and 1.62% FFA for carrageenan after the hydrolysis took place. Based on different biopolymer material used in immobilized beads, JD = 1.674 Re-0.4 for calcium alginate and JD = 1.881 Re-0.3 for k-carrageenan were found to be adequate to predict the experimental data for external mass transfer in the reactor in the Reynolds number range of 0.2 to 1.2. The purposed model can be used for the design of industrial bioreactor and scale up. Besides, the external mass transfer coefficients for the hydrolysis of Jatropha oil reaction and the entrapment efficiency for the two biopolymer materials used were also investigated.展开更多
Jatropha curcas was taken as the test material,6 concentrations including 0,25,50,100,200 and 400μmol/L AlCl3,plus 3 time gradients including 7,14 and 21 d,were set to study the effects of Al^(3+)stress on the antiox...Jatropha curcas was taken as the test material,6 concentrations including 0,25,50,100,200 and 400μmol/L AlCl3,plus 3 time gradients including 7,14 and 21 d,were set to study the effects of Al^(3+)stress on the antioxidant system of Jatropha curcas L.seedling.The results showed that with the Al^(3+)treatment being applied,protein content increased first,then decreased and finally increased with the increase of Al^(3+)concentration;the soluble sugar content increased first and then decreased with the increase of Al^(3+)concentration.Under low concentration of Al^(3+)treatment,Pro content,MDA content and POD activity of Jatropha curcas L.seedling leaves changed a little,while under high concentration of Al^(3+)treatment,Pro and MDA content of Jatropha curcas L.seedling leaves rapidly accumulated,POD activity increased and they showed a trend of increase with the increase of Al^(3+)concentration;From the perspective of Al^(3+)stress time,protein content,soluble sugar content,MDA content and POD activity increased with stress time being prolonged,while Pro content decreased with stress time being prolonged.These results indicated that the leaves of Jatropha curcas L.seedlings had certain self-protection and remediation abilities under Al^(3+)stress.展开更多
HXK(Hexokinase)gene family and the role of JcHXK1 in Jatropha curcas L.were explored.Totally 4 HXK genes JcHXK1,JcHXK2,JcHXK3 and JcHKL1 were identified and complete ORF of JcHXK1 was cloned.Functional domain,phylogen...HXK(Hexokinase)gene family and the role of JcHXK1 in Jatropha curcas L.were explored.Totally 4 HXK genes JcHXK1,JcHXK2,JcHXK3 and JcHKL1 were identified and complete ORF of JcHXK1 was cloned.Functional domain,phylogenetic evolution and low-temperature expression characteristics were analyzed.Results showed that full-length JcHXK1 cDNA was 1497 bp,encoding 498 amino acids with molecular weight of 53.81 kDa and pI of 5.03.Further phylogenetic evolutionary analysis demonstrated HXK1 protein was clustered into 6 small branches and 2 large branches.Sequence alignment showed that HXK1 contained several conserved glycine residues and hydrophobic channels.Prokaryotic expression vector of JcHXK1 was constructed and 12%SDS-PAGE detection showed that it was highly expressed in E.coli.These research was expected to lay a foundation for further gene functional verification and cold signal transduction mechanism for HXK1 in Jatropha curcas L.展开更多
The proteins from endosperm, root, stem, leaf, leafstalk of Jatropha curcas L. and their calli were hybridized to the seed toxin protein (curcin) of Jatropha curcas L. by western blot. The result showed that the curci...The proteins from endosperm, root, stem, leaf, leafstalk of Jatropha curcas L. and their calli were hybridized to the seed toxin protein (curcin) of Jatropha curcas L. by western blot. The result showed that the curcin was specifically expressed in the endosperm and its calli, while it was not detected in root, stem, leaf, and leafstalk of Jatropha curcas L. and their calli . This study indicated that calli induced from endosperm can be used to produce curcin.展开更多
基金Supported by Special Key R&D Fund from Yunnan Provincial Department of Education (ZD2010004)~~
文摘[Objective] The study aimed to investigate the changes of water status and different responses of osmoregulants during air-drought stress,to better understand mechanisms of drought resistance in Jatropha Curcas L. [Methods] The 12-day-old J. curcas seedlings were held in a climate chamber at 25/20 ℃(day/night),16 hours illumination,and 75% of relative humidity for air-drought treatment,and the changes of water potential,osmotic potential and the content of soluble sugar,proline,betaine were measured. [Results] Water potential and osmotic potential in leaves of J. curcas seedlings dropped significantly,pressure potential lost during air-drought stress,and the contents of osmoregulants soluble sugar,proline and betaine rose significantly to different extent in the leaves and stems. [Conclusion] Osmoregulants in the leaves and stems respond differently to air-drought stress,and in general leaves are much more responsive to the drought than stems of J. curcas seedlings.
文摘Yunnan Province is the main distributing area ofJatropha curcas L. This plant is abundant in several drainage areas of the dry-hot, dry-warm and sub-humid valleys in the south subtropical area of Yunnan Province. The seeds that were picked from trees blossoming between April and May and fructifying between September and October will have large seed yield and fine quality. For developing bio-diesel stock forest ofJ. curcas in areas with adaptive climate, seeding measures for afforestation should be taken and techniques on breeding, fast-growing, and high-yielding plantation cultivation are very important.
文摘In recent years, Jatropha curcas L. has gained popularity as a potential biodiesel plant. The varying oil content, reported between accessions belonging to different agroclimatic zones, has necessitated the assessment of the existing genetic variability to generate reliable molecular markers for selection of high oil yielding variety. EST derived SSR markers are more useful than genomic markers as they represent the transcriptome, thus, directly linked to functional genes. The present report describes the in silico mining of the microsatellites (SSRs) using J. curcas ESTs from various tissues viz. embryo, root, leaf and seed available in the public domain of NCBI. A total of 13,513 ESTs were downloaded. From these ESTs, 7552 unigenes were obtained and 395 SSRs were generated from 377 SSR-ESTs. These EST-SSRs can be used as potential microsatellite markers for diversity analysis, MAS etc. Since the Jatropha genes carrying SSRs have been identified in this study, thus, EST-SSRs directly linked to genes will be useful for developing trait linked markers.
文摘In recent years Jatropha curcas L. has emerged as a biofuel crop with potential for its production in marginal land with application of treated sewage water. Since this is a new crop for its profitable cultivation, additional research is needed to develop optimal management programs, including macro and micronutrients applications. A pot experiment was conducted in a Greenhouse at the National Research Center, Dokki, Cairo, Egypt, during 2010 summer to evaluate effects of varying concentrations of iron (Fe), manganese (Mn), and zinc (Zn) in irrigation water (0, 50, 100, 150, 200 and 250 ppm) on the growth, biomass production, photosynthetic pigments, and mineral nutrients status in the plants. Increasing concentrations of Fe, Mn, and Zn in irrigation water up to 150 ppm increased the biomass weight, photosynthetic pigments, and nutrient uptake by Jatropha plants. Further increase in concentrations of micronutrients showed negative effects on the above response parameters. Therefore, this study demonstrates that Jatropha can be grown under irrigation using waste water containing reasonable concentrations of micronutrients and heavy metals. This property of Jatropha provides some support for potential use of this crop for phytoremediation of metal contaminated soils. However, long term field research is needed to further verify both the above beneficial effects.
文摘During the last decade, Jatropha curcas L. (J. curcas) has gained much attention worldwide as biofuel crop. Although its cultivation is promoted in the Sahel, there is a surprising lack of data on its water use regulation and growth in this region. Here, we investigated, in semi-controlled conditions, leaf transpiration and growth of six accessions of J. curcas at seedling stage under natural changing in vapour pressure deficit (VPD) and progressive soil drying in Senegal. The experimental layout was a randomized complete bloc design and after 3 months of growth arranged to a split-plot at the implementation of water stress to facilitate irrigation. Under well water condition, there was no significant difference between accessions for leave transpiration that was positively correlated to VPD with high values recorded between 13 h and 14 h pm. Accessions of J. curcas used in this study showed closed thresholds at which transpiration declined except accession from Ndawene that threshold was lower (0.30). There is no significant difference between accessions for growth during the experimentation period. In 3 months, we recorded 23.57 g for the aboveground dry biomass and seedlings had about 14 leaves and 24.3 cm height. Positive linear correlation was recorded between aboveground biomass and root dry weight (p J. curcas might need complement irrigation for a better growth of seedlings especially during the dry season.
基金Supported by Doctoral Fund of Ministry of Education of China(20130181130006)the National Natural Science Foundation of China(No.21476150)
文摘Biodiesel, which is a renewable and environmentally friendly fuel, has been studied widely to help remedy increasing environmental problems. One of the key processes of biodiesel production is oil extraction from oilseed materials. Switchable solvents can reversibly change from molecular to ionic solvents under atmospheric CO_2,and can be used for oil extraction. N, N-dimethylcyclohexylamine(DMCHA), a switchable solvent, was used to extract oil from Jatropha curcas L. oil seeds to produce biodiesel. The appropriate extraction conditions were:1:2 ratio of seed mass to DMCHA volume, 0.3–1 mm particle size, 200 r·min-1agitation speed, 60 min extraction time, and 30 °C extraction temperature. The extraction ratio was about 83%. This solvent extracted the oil more efficiently than hexane, and is much less volatile. By bubbling CO_2 under 1 atm and 25 °C for 5 h, the oil was separated, and DMCHA was recovered after releasing CO_2 by bubbling N_2 under 1 atm and 60 °C for 2 h. The residual solvent content in oil was about 1.7%. Selectivity of DMCHA was evaluated by detecting the protein and sugar content in oil. Using the oil with residual solvent to conduct transesterification process, the oil conversion ratio was approximately 99.5%.
文摘An environmentally benign process was devel-oped for the transesterification of Jatropha curcas L. seed oil with methanol using artificial zeolites loaded with potassium acetate as a heterogeneous catalyst. After calcination for 5 h at 823 K, the catalyst loaded with 47 wt.% CH3COOK exhibited the highest efficiency and best catalytic activity. The easily prepared cata-lysts were characterized by means of X-ray dif-fraction and IR spectroscopy, as well as Hammett indicator titration. The results revealed a strong dependence of catalytic activity on ba-sicity. The optimum reaction conditions for transesterification of J. curcas oil were also in-vestigated. The methyl ester content in the bio-diesel product exceeded 91% after 4h reaction at reflux temperature in the presence of 2% solid catalyst and no water washing process is needed during workup.
基金Supported by the Key Grant Project of Chinese Ministry of Education (307023)the National Natural Science Foundation of China (20976108)the National Key Technology Research and Development Program (2007BAD50D05)
文摘Biodiesel produced from crude Jatropha curcas L.oil with trace sulfuric acid catalyst(0.02%-0.08% oil) was investigated at 135-184 ℃.Both esterification and transesterification can be well carried out simultane-ously.Factors affecting the process were investigated,which included the reaction temperature,reaction time,the molar ratio of alcohol to oil,catalyst amount,water content,free fatty acid(FFA) and fatty acid methyl ester(FAME) content.Under the conditions at 165 ℃,0.06%(by mass) H2SO4 of the oil mass,1.6 MPa and 20:1 methanol/oil ratio,the yield of glycerol reached 84.8% in 2 hours.FFA and FAME showed positive effect on the transesterification in certain extent.The water mass content below 1.0% did not show a noticeable effect on trans-esterification.Reaction kinetics in the range of 155 ℃ to 175 ℃ was also measured.
文摘Jatropha curcas L. (JCL) seeds were extracted and transesterified in-situ using supercritical methanol extraction in the absence of catalyst at different temperatures (200-280℃) and pressures (8-12 MPa), and at a fixed reaction time of 30 min with seeds-to-methanol ratio of 1:40 w/v. Design of experiment approach using five-level-two-factors design of Response Surface Methodology (RSM) was used to observe the effect of two independent variables i.e. temperature and pressure and the percent of biodiesel yield which required 13 runs. For optimization of the variables, Central Composite Rotatable Design (CCRD) was used for regression analysis and analysis of variance (ANOVA). The optimize conditions suggested by RSM were at T = 280℃ and P = 12.04 MPa. The predicted and experimental biodicsel yields were found to be 56.8% and 59.9%, respectively, with relatively small deviation errors of 1.59%.
文摘Objective To clone the ACP(acyl carrier protein)gene in Jatropha curcas L.,a potential anti-tumour and anti-fungal plant.And to determinate the expression of ACP in Jatropha curcas L.Methods A cDNA clone encoding ACP(acyl carrier protein)was isolated from Jatropha curcas L.endosperm cDNA library by random sequencing.The expression of ACP gene was investigated by semi-quantitative RT-PCR in leaves,stems and seeds of J.curca.The expression of ACP was also investigated in germinating seeds.The fragment encoding ACP protein in J.curca.was inserted into a prokaryotic expression vector pET28a(+).The gene was overexpressed in E.coli BL21 to produce abundant protein.Immunohistochemical analysis was used to detect the expression of ACP in different tissues of J.curca.Results The cDNA sequence was 806 bp in length and the ORF was 393 bp.The predicted molecular weight of the putative protein was 14.4 kD,pI=5.2.It contained a 4'-phosphopantetheine-binding motif.This prosthetic group can be combined with Serine of ACP protein.Semi-quantitative RT-PCR analysis showed that ACP gene was expressed in leaves,stems and seeds of J.curcas.The expression level of ACP was the highest in seeds and it was not detected in roots.After seeds germinated,the expression level of ACP in seeds increased progressively and reached a peak at 96 h.After induced by IPTG,SDS-PAGE analysis showed that the ACP protein of 20 kD was expressed.Immunohistochemical analysis showed that ACP specifical expressed abundantly in embyo of the seeds,and it was not detected in roots and the emdosperm while expressed in leaves and stems.Conclusions A cDNA clone encoding ACP which had all the typical characteristics of ACPs was isolated.It was expressed successfully in E.coli.The results of semi-quantitative RT-PCR analysis and immunohistochemical analysis were very similar,which showed that the expression of ACP in J.curcas.was abundant in seeds.The results indicated the expression related to the high metabolism.
文摘In this study, the methanolysis of mixed crop oils (Hevea brasiliensis and Jatropha curcas L.) was investigated. Due to the oils contain high impurities, a particular pre-treatment of which was carried out. For alkali-catalyzed methanolysis, few parameters (such as: molar ratio, catalyst percentage, and reaction time) were studied. The results showed that the methanolysis optimum conditions were 5.5 of molar ratio, 0.9% w/w of catalyst, and 60 minutes of reaction time with the highest yield of 98.9%. The kinetics study indicated that first order reaction mechanism with reaction rate constant and activation energy were 1.5 × 10-2 minute-1 and 23.93 KJ?mol-1 respectively. As fuel, the physicochemical properties of biodiesel met the standard values required by ASTM D6751.
文摘Background:Diabetes mellitus is a chronic metabolic disease that is a risk factor for epidemic pathologies.Under hyperglycemic conditions,the enzyme aldose reductase catalyzes the formation of sorbitol in the metabolism of glucose via polyols,leading to the development of diabetic complications.Therefore,inhibitors of this enzyme are therapeutic targets for the prophylaxis and treatment of these conditions.Methods:In this study,a generalized linear regression model was developed to analyze flavonoids-obtained from a database-that have been tested as inhibitors of aldose reductase.In this sense,the molecular descriptors implemented in DRAGON and MATLAB software were used to determine the correlation between the chemical structure of the inhibitors and their pharmacological activity.The model was validated according to the Organisation for Economic Co-operation and Development Standards and subsequently used for the virtual screening of the flavonoids identified in Jatropha gossypiifolia L.Results:The proposed model showed a good fit for its statistical parameters(R2=0.95).In addition,it showed good predictive power(R2 ext=0.94)and robustness(Q2 LOO=0.92).The experimental chemical space wherein the predictions were reliable(domain of application)was also defined.Finally,the model was used to identify 10 flavonoids from Jatropha gossypiifolia L.as candidates for natural drugs.Compounds with a low probability of oral absorption were identified,among which the elagic acid biflavonoid showed the greatest promise(pIC50 predicted=9.75).Conclusion:The Jatropha gossypiifolia L.species harbors flavonoids with high potential as inhibitors of the aldose reductase enzyme,in which the biflavonoid ellagic acid was shown to be the most promising inhibitor of the aldose reductase enzyme,suggesting its possible use in the treatment of the late complications of diabetes mellitus.
文摘In this study, a simple and effective technique for establishing an external mass transfer model in a recirculated packed-bed batch reactor (RPBBR) with an immobilized lipase enzyme and Jatropha oil system is presented. The external mass transfer effect can be represented with a model in the form of Colburn factor JD = K Re-(1–n). The value of K and n were derived from experimental data at different mass flow rates.The experiment shows an average increment of 1.51% FFA for calcium alginate and 1.62% FFA for carrageenan after the hydrolysis took place. Based on different biopolymer material used in immobilized beads, JD = 1.674 Re-0.4 for calcium alginate and JD = 1.881 Re-0.3 for k-carrageenan were found to be adequate to predict the experimental data for external mass transfer in the reactor in the Reynolds number range of 0.2 to 1.2. The purposed model can be used for the design of industrial bioreactor and scale up. Besides, the external mass transfer coefficients for the hydrolysis of Jatropha oil reaction and the entrapment efficiency for the two biopolymer materials used were also investigated.
文摘Jatropha curcas was taken as the test material,6 concentrations including 0,25,50,100,200 and 400μmol/L AlCl3,plus 3 time gradients including 7,14 and 21 d,were set to study the effects of Al^(3+)stress on the antioxidant system of Jatropha curcas L.seedling.The results showed that with the Al^(3+)treatment being applied,protein content increased first,then decreased and finally increased with the increase of Al^(3+)concentration;the soluble sugar content increased first and then decreased with the increase of Al^(3+)concentration.Under low concentration of Al^(3+)treatment,Pro content,MDA content and POD activity of Jatropha curcas L.seedling leaves changed a little,while under high concentration of Al^(3+)treatment,Pro and MDA content of Jatropha curcas L.seedling leaves rapidly accumulated,POD activity increased and they showed a trend of increase with the increase of Al^(3+)concentration;From the perspective of Al^(3+)stress time,protein content,soluble sugar content,MDA content and POD activity increased with stress time being prolonged,while Pro content decreased with stress time being prolonged.These results indicated that the leaves of Jatropha curcas L.seedlings had certain self-protection and remediation abilities under Al^(3+)stress.
基金supported by the National Natural Science Foundation of China(31460179,2017FG001-51)。
文摘HXK(Hexokinase)gene family and the role of JcHXK1 in Jatropha curcas L.were explored.Totally 4 HXK genes JcHXK1,JcHXK2,JcHXK3 and JcHKL1 were identified and complete ORF of JcHXK1 was cloned.Functional domain,phylogenetic evolution and low-temperature expression characteristics were analyzed.Results showed that full-length JcHXK1 cDNA was 1497 bp,encoding 498 amino acids with molecular weight of 53.81 kDa and pI of 5.03.Further phylogenetic evolutionary analysis demonstrated HXK1 protein was clustered into 6 small branches and 2 large branches.Sequence alignment showed that HXK1 contained several conserved glycine residues and hydrophobic channels.Prokaryotic expression vector of JcHXK1 was constructed and 12%SDS-PAGE detection showed that it was highly expressed in E.coli.These research was expected to lay a foundation for further gene functional verification and cold signal transduction mechanism for HXK1 in Jatropha curcas L.
文摘The proteins from endosperm, root, stem, leaf, leafstalk of Jatropha curcas L. and their calli were hybridized to the seed toxin protein (curcin) of Jatropha curcas L. by western blot. The result showed that the curcin was specifically expressed in the endosperm and its calli, while it was not detected in root, stem, leaf, and leafstalk of Jatropha curcas L. and their calli . This study indicated that calli induced from endosperm can be used to produce curcin.