Rauwolfia species(Apocynaceae) are medicinal plants well known worldwide due to its potent bioactive monoterpene indole alkaloids(MIAs) such as reserpine,ajmalicine,ajmaline,serpentine and yohimbine.Reserpine,ajmalici...Rauwolfia species(Apocynaceae) are medicinal plants well known worldwide due to its potent bioactive monoterpene indole alkaloids(MIAs) such as reserpine,ajmalicine,ajmaline,serpentine and yohimbine.Reserpine,ajmalicine and ajmaline are powerful antihypertensive,tranquilizing agents used in hypertension.Yohimbine is an aphrodisiac used in dietary supplements.As there is no report on the comparative and comprehensive phytochemical investigation of the roots of Rauwolfia species,we have developed an efficient and reliable liquid chromatography-tandem mass spectrometry(LC–MS/MS) method for ethanolic root extract of Rauwolfia species to elucidate the fragmentation pathways for dereplication of bioactive MIAs using highperformance liquid chromatography coupled with electrospray ionization quadrupole time-of-flight tandem mass spectrometry(HPLC–ESI–QTOF–MS/MS) in positive ion mode.We identified and established diagnostic fragment ions and fragmentation pathways using reserpine,ajmalicine,ajmaline,serpentine and yohimbine.The MS/MS spectra of reserpine,ajmalicine,and ajmaline showed C-ring-cleavage whereas E-ring cleavage was observed in serpentine via Retro Diels Alder(RDA).A total of 47 bioactive MIAs were identified and characterized on the basis of their molecular formula,exact mass measurements and MS/MS analysis.Reserpine,ajmalicine,ajmaline,serpentine and yohimbine were unambiguously identified by comparison with their authentic standards and other 42 MIAs were tentatively identified and characterized from the roots of Rauwolfia hookeri,Rauwolfia micrantha,Rauwolfia serpentina,Rauwolfia verticillata,Rauwolfia tetraphylla and Rauwolfia vomitoria.Application of LC–MS followed by principal component analysis(PCA) has been successfully used to discriminate among six Rauwolfia species.展开更多
Phyllanthus species plants are a rich source of phenolics and widely used due to their medicinal properties. A liquid chromatography–tandem mass spectrometry(LC–MS/MS) method was developed using high-pressure liquid...Phyllanthus species plants are a rich source of phenolics and widely used due to their medicinal properties. A liquid chromatography–tandem mass spectrometry(LC–MS/MS) method was developed using high-pressure liquid chromatography coupled with quadrupole time-of-flight tandem mass spectrometry(HPLC-ESI-QTOFMS/MS) for the identification and characterization of quercetin, kaempferol, ellagic acid and their derivatives in ethanolic extracts of Phyllanthus species. The chromatographic separation was carried out on Thermo Betasil C_8 column(250 mm×4.5 mm, 5 μm) using 0.1% formic acid in water and 0.1% formic acid in methanol as the mobile phase. The identification of diagnostic fragment ions and optimization of collision energies were carried out using 21 reference standards. Totally 51 compounds were identified which include 21 compounds identified and characterized unambiguously by comparison with their authentic standards and the remaining 30 were tentatively identified and characterized in ethanolic extracts of P. emblica, P. fraternus, P. amarus and P.niruri.展开更多
Mahonia leschenaultia（ML） and Mahonia napaulensis（MN） are less known and unexplored medicinal plants of the family Berberidaceae. They are used by the Todas of Nilgiris in their religious and medical practices but...Mahonia leschenaultia（ML） and Mahonia napaulensis（MN） are less known and unexplored medicinal plants of the family Berberidaceae. They are used by the Todas of Nilgiris in their religious and medical practices but chemically less identified. Hence, we decided to do extensive phytochemical analysis to explore the potential of these plant extracts. An ultrahigh performance electrospray tandem mass spectrometry（UHPLC-ESI-MS/MS）method was successfully developed for qualitative analysis of the bioactive components in Mahonia species using Orbitrap Velos Pro mass spectrometer. Sixteen compounds were identified by comparison of their retention times and mass spectra（MS） with authentic standards and reported literature. Multi-stage mass spectra（MS（2-8）） for the identification of protoberberine and aporphine alkaloids showed the sequential expulsion of all the substituents attached with their basic skeleton followed by CO loss. Eight of the identified compounds（berberine, jatrorrhizine, palmatine, magnoflorine, isocorydine, glaucine, tetrahydropalmatine and tetrahydroberberine） were simultaneously determined by another UHPLC-ESI-MS/MS method under the multiple reactions monitoring（MRM） mode quantitatively using triple quadrupole linear ion trap mass spectrometer. The analytical method was validated for 8 bioactive compounds with overall recovery in the range98.5%-103.6%（RSD≤2.2%）, precise（RSD≤2.07%） and linear（r≥0.9995） over the concentration range of 0.5-1000 ng/mL and successfully applied in ML and MN roots, which suggests the suitability of the proposed approach for the routine analysis of Mahonia species and their quality control.展开更多
Berberis petiolaris Wall. ex G. Don, an unexplored medicinal plant belonging to the family Berberidaceae, is a large deciduous shrub found in Western Himalaya between 1800-3000 m. Chemical profiling of fruit, leaf, ro...Berberis petiolaris Wall. ex G. Don, an unexplored medicinal plant belonging to the family Berberidaceae, is a large deciduous shrub found in Western Himalaya between 1800-3000 m. Chemical profiling of fruit, leaf, root and stem was done by direct analysis in real time mass spectrometry followed by multivariate analysis for discrimination among the plant parts. The bioactive compounds, including magnofiorine, berberine, jatrorrhizine, thalifendine/berberrubine, demethyleneberberine, reticuline, 8-oxoberberine, N-methyltetrahydroberberine, tetrahydropalmatine, tetrahydroberberine and palmatine, were identified by their exact mass measurement and the corresponding molecular formula of each compound. A comparative study of distribution pattern for all these bioactive alkaloids showed qualitative and quantitative variations in different parts of B. petiolaris. Principal component analysis clearly dis- criminated each part of B. petiolaris plant.展开更多
The hydrology of Himalayan region is influenced by temperature lapse rate(TLAPS)and precipitation lapse rate(PLAPS).Therefore,hydrological modeling considering TLAPS and PLAPS is crucial to manage the water resources ...The hydrology of Himalayan region is influenced by temperature lapse rate(TLAPS)and precipitation lapse rate(PLAPS).Therefore,hydrological modeling considering TLAPS and PLAPS is crucial to manage the water resources in these terrains.In this research,Himalayan Gandak River basin is considered as the study area where TLAPS and PLAPS vary significantly due to high altitude of Himalayas.To assess the impact of TLAPS and PLAPS on water balance components,Soil Water Assessment Tool(SWAT)model was calibrated(2000-2007)and validated(2008-2014)on daily time step for three projects i.e.,Reference Project(RP),Snowmelt Project(SP)and distributed elevation band snowmelt project(SWAT-ETISM).The analysis discloses that SWAT-ETISM model(which has TLAPS and PLAPS parameters)outperforms the RP and the SP models in predicting streamflow with improved statistical indicators R2=0.88,NSE=0.84 and PBIAS=11.9.Furthermore,it was observed that SWAT-ETISM model comprehensively improved the streamflow statistics by improving the snow water equivalent and water balance components through the consideration of TLAPS and PLAPS values for the region.Hence,the proposed SWAT-ETISM model can be used for estimation of the water budget at the high-altitude and data scarce alpine Himalayan regions and worldwide,where PLAPS and TLAPS are substantial due to altitudinal variation.展开更多
Steady state behavior analysis of organic thin film transistor(OTFTs)has been thoroughly researched in the past few decades.Yet,this static logic analysis has drawbacks of high power dissipation and high power consump...Steady state behavior analysis of organic thin film transistor(OTFTs)has been thoroughly researched in the past few decades.Yet,this static logic analysis has drawbacks of high power dissipation and high power consumption,and a large number of prerequisites in the number of transistors for the digital logic circuit application.Hence,to overcome these basic fundamental drawbacks of static logic,the dynamic logic study of organic thin film transistor has been analyzed in this paper.The fundamental basic of dynamic logic is a pass transistor for which logic high and logic low model is designed at an operating voltage of 5 V and frequency of 5 kHz.Additionally,the novel approach of analytical model for organic pass transistor(OPT)circuit is included and verified using MATLAB.The transient individualities of organic pass transistor OPT are examined through Atlas 2-D numerical device simulator.The reduction in the power dissipation along with additional voltage scaling and reduction in the clock frequency such as pipelining may further enable the applications into more complex VLSI ICs.展开更多
基金Council of Scientific Industrial Research,India for providing financial support
文摘Rauwolfia species(Apocynaceae) are medicinal plants well known worldwide due to its potent bioactive monoterpene indole alkaloids(MIAs) such as reserpine,ajmalicine,ajmaline,serpentine and yohimbine.Reserpine,ajmalicine and ajmaline are powerful antihypertensive,tranquilizing agents used in hypertension.Yohimbine is an aphrodisiac used in dietary supplements.As there is no report on the comparative and comprehensive phytochemical investigation of the roots of Rauwolfia species,we have developed an efficient and reliable liquid chromatography-tandem mass spectrometry(LC–MS/MS) method for ethanolic root extract of Rauwolfia species to elucidate the fragmentation pathways for dereplication of bioactive MIAs using highperformance liquid chromatography coupled with electrospray ionization quadrupole time-of-flight tandem mass spectrometry(HPLC–ESI–QTOF–MS/MS) in positive ion mode.We identified and established diagnostic fragment ions and fragmentation pathways using reserpine,ajmalicine,ajmaline,serpentine and yohimbine.The MS/MS spectra of reserpine,ajmalicine,and ajmaline showed C-ring-cleavage whereas E-ring cleavage was observed in serpentine via Retro Diels Alder(RDA).A total of 47 bioactive MIAs were identified and characterized on the basis of their molecular formula,exact mass measurements and MS/MS analysis.Reserpine,ajmalicine,ajmaline,serpentine and yohimbine were unambiguously identified by comparison with their authentic standards and other 42 MIAs were tentatively identified and characterized from the roots of Rauwolfia hookeri,Rauwolfia micrantha,Rauwolfia serpentina,Rauwolfia verticillata,Rauwolfia tetraphylla and Rauwolfia vomitoria.Application of LC–MS followed by principal component analysis(PCA) has been successfully used to discriminate among six Rauwolfia species.
基金CSIR, New Delhi, India, for financial supportBK for NMPB grant GO/UP/03/09
文摘Phyllanthus species plants are a rich source of phenolics and widely used due to their medicinal properties. A liquid chromatography–tandem mass spectrometry(LC–MS/MS) method was developed using high-pressure liquid chromatography coupled with quadrupole time-of-flight tandem mass spectrometry(HPLC-ESI-QTOFMS/MS) for the identification and characterization of quercetin, kaempferol, ellagic acid and their derivatives in ethanolic extracts of Phyllanthus species. The chromatographic separation was carried out on Thermo Betasil C_8 column(250 mm×4.5 mm, 5 μm) using 0.1% formic acid in water and 0.1% formic acid in methanol as the mobile phase. The identification of diagnostic fragment ions and optimization of collision energies were carried out using 21 reference standards. Totally 51 compounds were identified which include 21 compounds identified and characterized unambiguously by comparison with their authentic standards and the remaining 30 were tentatively identified and characterized in ethanolic extracts of P. emblica, P. fraternus, P. amarus and P.niruri.
文摘Mahonia leschenaultia（ML） and Mahonia napaulensis（MN） are less known and unexplored medicinal plants of the family Berberidaceae. They are used by the Todas of Nilgiris in their religious and medical practices but chemically less identified. Hence, we decided to do extensive phytochemical analysis to explore the potential of these plant extracts. An ultrahigh performance electrospray tandem mass spectrometry（UHPLC-ESI-MS/MS）method was successfully developed for qualitative analysis of the bioactive components in Mahonia species using Orbitrap Velos Pro mass spectrometer. Sixteen compounds were identified by comparison of their retention times and mass spectra（MS） with authentic standards and reported literature. Multi-stage mass spectra（MS（2-8）） for the identification of protoberberine and aporphine alkaloids showed the sequential expulsion of all the substituents attached with their basic skeleton followed by CO loss. Eight of the identified compounds（berberine, jatrorrhizine, palmatine, magnoflorine, isocorydine, glaucine, tetrahydropalmatine and tetrahydroberberine） were simultaneously determined by another UHPLC-ESI-MS/MS method under the multiple reactions monitoring（MRM） mode quantitatively using triple quadrupole linear ion trap mass spectrometer. The analytical method was validated for 8 bioactive compounds with overall recovery in the range98.5%-103.6%（RSD≤2.2%）, precise（RSD≤2.07%） and linear（r≥0.9995） over the concentration range of 0.5-1000 ng/mL and successfully applied in ML and MN roots, which suggests the suitability of the proposed approach for the routine analysis of Mahonia species and their quality control.
文摘Berberis petiolaris Wall. ex G. Don, an unexplored medicinal plant belonging to the family Berberidaceae, is a large deciduous shrub found in Western Himalaya between 1800-3000 m. Chemical profiling of fruit, leaf, root and stem was done by direct analysis in real time mass spectrometry followed by multivariate analysis for discrimination among the plant parts. The bioactive compounds, including magnofiorine, berberine, jatrorrhizine, thalifendine/berberrubine, demethyleneberberine, reticuline, 8-oxoberberine, N-methyltetrahydroberberine, tetrahydropalmatine, tetrahydroberberine and palmatine, were identified by their exact mass measurement and the corresponding molecular formula of each compound. A comparative study of distribution pattern for all these bioactive alkaloids showed qualitative and quantitative variations in different parts of B. petiolaris. Principal component analysis clearly dis- criminated each part of B. petiolaris plant.
文摘The hydrology of Himalayan region is influenced by temperature lapse rate(TLAPS)and precipitation lapse rate(PLAPS).Therefore,hydrological modeling considering TLAPS and PLAPS is crucial to manage the water resources in these terrains.In this research,Himalayan Gandak River basin is considered as the study area where TLAPS and PLAPS vary significantly due to high altitude of Himalayas.To assess the impact of TLAPS and PLAPS on water balance components,Soil Water Assessment Tool(SWAT)model was calibrated(2000-2007)and validated(2008-2014)on daily time step for three projects i.e.,Reference Project(RP),Snowmelt Project(SP)and distributed elevation band snowmelt project(SWAT-ETISM).The analysis discloses that SWAT-ETISM model(which has TLAPS and PLAPS parameters)outperforms the RP and the SP models in predicting streamflow with improved statistical indicators R2=0.88,NSE=0.84 and PBIAS=11.9.Furthermore,it was observed that SWAT-ETISM model comprehensively improved the streamflow statistics by improving the snow water equivalent and water balance components through the consideration of TLAPS and PLAPS values for the region.Hence,the proposed SWAT-ETISM model can be used for estimation of the water budget at the high-altitude and data scarce alpine Himalayan regions and worldwide,where PLAPS and TLAPS are substantial due to altitudinal variation.
文摘Steady state behavior analysis of organic thin film transistor(OTFTs)has been thoroughly researched in the past few decades.Yet,this static logic analysis has drawbacks of high power dissipation and high power consumption,and a large number of prerequisites in the number of transistors for the digital logic circuit application.Hence,to overcome these basic fundamental drawbacks of static logic,the dynamic logic study of organic thin film transistor has been analyzed in this paper.The fundamental basic of dynamic logic is a pass transistor for which logic high and logic low model is designed at an operating voltage of 5 V and frequency of 5 kHz.Additionally,the novel approach of analytical model for organic pass transistor(OPT)circuit is included and verified using MATLAB.The transient individualities of organic pass transistor OPT are examined through Atlas 2-D numerical device simulator.The reduction in the power dissipation along with additional voltage scaling and reduction in the clock frequency such as pipelining may further enable the applications into more complex VLSI ICs.
