A new lupane-type triterpene was isolated from the resin of Boswellia carterii Birdw. Based on the spectral methods, its structure was elucidated as lup-20(29)-ene-3a-acetoxy-24-oic acid.
Objective:To provide further evidence for the ethnomedicinal use of the Eastern Nigeria mistletoe,Loranthus micranthus(L.micranthus),as an immunostimulant.Methods:Solvent fractions from the crude extract of the mistle...Objective:To provide further evidence for the ethnomedicinal use of the Eastern Nigeria mistletoe,Loranthus micranthus(L.micranthus),as an immunostimulant.Methods:Solvent fractions from the crude extract of the mistletoe plant was obtained and screened by the cell mediated delayed type hypersensitivity reaction(DTHR) model in mice.Then the immunomodulatory potentials of a major lupane triterpenoid ester isolated from an active hexane fraction of the Eastern Nigeria mistletoe was investigated.Three lupeol-based triterpenoid esters: 7β15α-dihydroxyl-lup-20(29)-ene-3β-palmitate(Ⅰ),7β,15α-dihydroxyl-lup-20(29)- ene-3β-stearate(Ⅱ) and 7β,15α-dihydroxyl-lup-20(29)-ene-3β-decadecanoate(Ⅲ) were isolated from the plant leaves epiphyting on a local kola nut tree and were characterized. Compound 1 was subjected to cell proliferation studies using C57H1/6 splenocvtes at three dose levels(5.25 and 100μg/mL) in presence of controls.Furthermore,the effect of this compound on IL-8 receptor expression was evaluated at three doses(1,5 and 10μg/mL) using the real time polymerase chain reaction assay.Results:This triterpenoid ester produced some enhancement of the splenocytes at the tested doses but at doses higher than 5μg/mL caused inhibition of the IL-8 receptor expression.Conclusions:The present findings support the ethnomedicinal use of the Eastern Nigeria Mistletoe in the management of diseases affecting the immune system.The trilerpenoid(s) have some immunomodulatory abilities on splenocytes and IL-8 receptors and may partly account lor the overall immunomodulatory activity of this plant.展开更多
γ-Lupane (2) and iso-γ-lupane (10) (3α-isopropyl, 5αH) were synthesized from lupeol. The reaction conditions of conversion of lupeol into lupenes and γ-lupenes and the results of catalytic hydrogenation of lupene...γ-Lupane (2) and iso-γ-lupane (10) (3α-isopropyl, 5αH) were synthesized from lupeol. The reaction conditions of conversion of lupeol into lupenes and γ-lupenes and the results of catalytic hydrogenation of lupenes and γ-lupenes under different conditions were studied.展开更多
Coal Bed Methane(CBM)is natural gas occurring in coal seams.It can be used for domestic(heating and cooking)and industrial purposes,electricity generation,transportation(as compressed natural gas or liquefied natural ...Coal Bed Methane(CBM)is natural gas occurring in coal seams.It can be used for domestic(heating and cooking)and industrial purposes,electricity generation,transportation(as compressed natural gas or liquefied natural gas),and in boilers supporting mining operations.It is established that Zimbabwe has CBM in the North-Western region.At the time of this study,only one organization(Industrial Development Corporation)has reported an Original Gas in Place(OGIP)estimate for the region as 765 Bm3.In this study we use Monte Carlo Simulation(MCS)to estimate the range of OGIP values for the region.MCS is a widely used probabilistic method,preferred over deterministic methods in which only best-estimate values of parameters are used to predict a single OGIP value.This single OGIP value may be either positively(overestimated)or negatively skewed(underestimated).However,the probabilistic approach using MCS accounts for the uncertainty in values of parameters.This is done by incorporating appropriate range and probability distributions(e.g.triangular,normal,uniform,etc.)of input parameters(e.g.target area,formation thickness,coal bulk density,and adsorbed methane content),and repeating calculations to generate a cumulative distribution curve for the OGIP.The generated curve provides statistical confidence levels represented as probability distributions,i.e.P10,P50,and P90 represents low,mid,and high probability estimates,respectively.Our results show that P10,P50,and P90 values for the North-Western region OGIP are 5699 Bm3,2347 Bm3,and 706 Bm3,respectively.The Resource Density(RD)estimation is found to range from 0.015 Bm3/km2 to 0.113 Bm3/km2 over the geographic area.This range is comparable to Alberta plains shallow and deep basins in Canada which boosts a higher level of confidence for CBM potential in Zimbabwe.The results are encouraging for further exploration and planning of exploitation of CBM in Zimbabwe.展开更多
Objective To identify the active compounds from the barks of Betula platyphylla for inhibitory on diacylglycerol acyltransferase（DGAT1）.Methods Bioassay-guided fractionation resulted in the isolation of DGAT1 inhibi...Objective To identify the active compounds from the barks of Betula platyphylla for inhibitory on diacylglycerol acyltransferase（DGAT1）.Methods Bioassay-guided fractionation resulted in the isolation of DGAT1 inhibitory activity of lupane triterpenes.Results Ten compounds were identified as lupenone（1）,lupeol（2）,betulinic acid（3）,betulinaldehyde（4）,betulin（5）,3-deoxybetulonic acid（6）,glochidonol（7）,lup-20/29-ene-1β/3β-diol（8）,3α-hydroxy-lup-20（29）-en-23,28-dioic acid（9）,and 3α,11α-dihydroxy-23-oxo-lup-20（29）-en-28-oic acid（10）.Compounds 3-6,9,and 10 inhibited DGAT1 with IC50 values ranging from（11.2±0.3）to（38.6±1.2）μmol/L.Conclusion Compounds 6,9,and 10 are first isolated from the barks of B.platyphylla.,and compounds 3-6,9,and 10 from the barks of B.platyphylla are responsible for the inhibition on DGAT1.展开更多
文摘A new lupane-type triterpene was isolated from the resin of Boswellia carterii Birdw. Based on the spectral methods, its structure was elucidated as lup-20(29)-ene-3a-acetoxy-24-oic acid.
基金The NIH/NIPRD/FCN drug symposium travel grant award to the corresponding author in 2009the 2008 innovators of tomorrow(IOT) grant award from STEP-B project in Nigeria
文摘Objective:To provide further evidence for the ethnomedicinal use of the Eastern Nigeria mistletoe,Loranthus micranthus(L.micranthus),as an immunostimulant.Methods:Solvent fractions from the crude extract of the mistletoe plant was obtained and screened by the cell mediated delayed type hypersensitivity reaction(DTHR) model in mice.Then the immunomodulatory potentials of a major lupane triterpenoid ester isolated from an active hexane fraction of the Eastern Nigeria mistletoe was investigated.Three lupeol-based triterpenoid esters: 7β15α-dihydroxyl-lup-20(29)-ene-3β-palmitate(Ⅰ),7β,15α-dihydroxyl-lup-20(29)- ene-3β-stearate(Ⅱ) and 7β,15α-dihydroxyl-lup-20(29)-ene-3β-decadecanoate(Ⅲ) were isolated from the plant leaves epiphyting on a local kola nut tree and were characterized. Compound 1 was subjected to cell proliferation studies using C57H1/6 splenocvtes at three dose levels(5.25 and 100μg/mL) in presence of controls.Furthermore,the effect of this compound on IL-8 receptor expression was evaluated at three doses(1,5 and 10μg/mL) using the real time polymerase chain reaction assay.Results:This triterpenoid ester produced some enhancement of the splenocytes at the tested doses but at doses higher than 5μg/mL caused inhibition of the IL-8 receptor expression.Conclusions:The present findings support the ethnomedicinal use of the Eastern Nigeria Mistletoe in the management of diseases affecting the immune system.The trilerpenoid(s) have some immunomodulatory abilities on splenocytes and IL-8 receptors and may partly account lor the overall immunomodulatory activity of this plant.
基金The project was supported by the National Natural Science Foundation of China
文摘γ-Lupane (2) and iso-γ-lupane (10) (3α-isopropyl, 5αH) were synthesized from lupeol. The reaction conditions of conversion of lupeol into lupenes and γ-lupenes and the results of catalytic hydrogenation of lupenes and γ-lupenes under different conditions were studied.
文摘Coal Bed Methane(CBM)is natural gas occurring in coal seams.It can be used for domestic(heating and cooking)and industrial purposes,electricity generation,transportation(as compressed natural gas or liquefied natural gas),and in boilers supporting mining operations.It is established that Zimbabwe has CBM in the North-Western region.At the time of this study,only one organization(Industrial Development Corporation)has reported an Original Gas in Place(OGIP)estimate for the region as 765 Bm3.In this study we use Monte Carlo Simulation(MCS)to estimate the range of OGIP values for the region.MCS is a widely used probabilistic method,preferred over deterministic methods in which only best-estimate values of parameters are used to predict a single OGIP value.This single OGIP value may be either positively(overestimated)or negatively skewed(underestimated).However,the probabilistic approach using MCS accounts for the uncertainty in values of parameters.This is done by incorporating appropriate range and probability distributions(e.g.triangular,normal,uniform,etc.)of input parameters(e.g.target area,formation thickness,coal bulk density,and adsorbed methane content),and repeating calculations to generate a cumulative distribution curve for the OGIP.The generated curve provides statistical confidence levels represented as probability distributions,i.e.P10,P50,and P90 represents low,mid,and high probability estimates,respectively.Our results show that P10,P50,and P90 values for the North-Western region OGIP are 5699 Bm3,2347 Bm3,and 706 Bm3,respectively.The Resource Density(RD)estimation is found to range from 0.015 Bm3/km2 to 0.113 Bm3/km2 over the geographic area.This range is comparable to Alberta plains shallow and deep basins in Canada which boosts a higher level of confidence for CBM potential in Zimbabwe.The results are encouraging for further exploration and planning of exploitation of CBM in Zimbabwe.
基金Science and Technology Development Program of Jilin Province(201205099)
文摘Objective To identify the active compounds from the barks of Betula platyphylla for inhibitory on diacylglycerol acyltransferase（DGAT1）.Methods Bioassay-guided fractionation resulted in the isolation of DGAT1 inhibitory activity of lupane triterpenes.Results Ten compounds were identified as lupenone（1）,lupeol（2）,betulinic acid（3）,betulinaldehyde（4）,betulin（5）,3-deoxybetulonic acid（6）,glochidonol（7）,lup-20/29-ene-1β/3β-diol（8）,3α-hydroxy-lup-20（29）-en-23,28-dioic acid（9）,and 3α,11α-dihydroxy-23-oxo-lup-20（29）-en-28-oic acid（10）.Compounds 3-6,9,and 10 inhibited DGAT1 with IC50 values ranging from（11.2±0.3）to（38.6±1.2）μmol/L.Conclusion Compounds 6,9,and 10 are first isolated from the barks of B.platyphylla.,and compounds 3-6,9,and 10 from the barks of B.platyphylla are responsible for the inhibition on DGAT1.
