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Weidong Zhang - One of the best experts on this subject based on the ideXlab platform.
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simultaneous determination of six Steroidal Alkaloids of veratrum dahuricum by hplc elsd and hplc msn
Chromatographia, 2008Co-Authors: Jian Tang, Weidong Zhang, Yunheng Shen, Runhui Liu, Huizi Jin, Shikai YanAbstract:A high performance liquid chromatography coupled with evaporative light scattering detection (HPLC–ELSD) and electrospray ionization multistage mass spectrometry (HPLC–ESI–MSn), respectively, has been performed for the simultaneous determination of six Steroidal Alkaloids, including pseudojervine, veratrosine, jervine, veratramine, 3-veratroylzygadenine, 3-angeloylzygadenine, in Veratrum dahuricum collected in different seasons. The plants were soaked in methanol and extracted ultrasonically. The six Steroidal Alkaloids were obtained by silica gel column chromatography, eluting with gradient petroleum and acetyl acetate. The intra-day and inter-day precisions of the method were evaluated and were less than 1.4%. The content of Steroidal Alkaloids in the plant varied significantly from spring to autumn, confirming the necessity to control the quality of V. dahuricum during its preparation and application.
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two new Steroidal Alkaloids from veratrum nigrum l
Helvetica Chimica Acta, 2008Co-Authors: Bin Wang, Weidong Zhang, Yunheng Shen, Jian Tang, Chuan Zhang, Runhui Liu, Min LinAbstract:Phytochemical studies on Veratrum nigrum L., collected in Shanxi, P. R. China, resulted in the isolation of two new Steroidal Alkaloids, 23-methoxycyclopamine (1) and 15-O-(2-methylbutanoyl)-3-O-veratroylprotoverine (2). The structures of the two new compounds were established by means of extensive NMR spectroscopic studies.
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characterization and identification of Steroidal Alkaloids in the chinese herb veratrum nigrum l by high performance liquid chromatography electrospray ionization with multi stage mass spectrometry
Rapid Communications in Mass Spectrometry, 2007Co-Authors: Jian Tang, Bin Wang, Weidong Zhang, Chuan Zhang, Runhui Liu, Min Lin, Haiqiang HuangAbstract:Electrospray ionization multi-stage mass spectrometry (ESI-MSn) was performed to study the fragmentation behaviour of seventeen Steroidal Alkaloids (4 protoverine-type Alkaloids, 10 germine-type Alkaloids and 3 zygadenin-type Alkaloids) from the Chinese herb Veratrum nigrum L. The MSn spectra of the [M+H]+ ions for Steroidal Alkaloids provided a wealth of structural information on the substituted groups. In positive ion mode, the three types of Alkaloids showed very different characteristic ions: m/z 436 or 418 for protoverine-type Alkaloids; m/z 438, 420 or 402 for germine-type Alkaloids; m/z 440 or 422 for zygadenin-type Alkaloids. These fragments were used to deduce their mass spectral fragmentation mechanisms. Furthermore, the primary compounds in methanolic extracts of the herb of Veratrum nigrum L. were investigated by using liquid chromatography (LC)/ESI-MSn. As a result, 21 Steroidal Alkaloids (5 protoverine-type Alkaloids, 14 germine-type Alkaloids and 2 zygadenin-type Alkaloids) were selectively identified from 27 determined peaks. Eleven compounds were unambiguously identified by comparing with standard compounds and ten compounds were tentatively identified or deduced according to their MSn data. Two of these compounds (xingangermine and deacetyl xinganveratrine) were found to be novel Steroidal Alkaloids. In addition, the chemical structures of two pairs of Steroidal alkaloid isomers were deduced by comparing their fragment ions. Given the important structural information of known and unknown Steroidal Alkaloids in crude herbal extracts, this study is useful for identifying these types of Steroidal Alkaloids in crude materials rapidly and selectively. Copyright © 2007 John Wiley & Sons, Ltd.
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characterization and identification of Steroidal Alkaloids in the chinese herb veratrum nigrum l by high performance liquid chromatography electrospray ionization with multi stage mass spectrometry
Rapid Communications in Mass Spectrometry, 2007Co-Authors: Jian Tang, Bin Wang, Weidong Zhang, Chuan Zhang, Runhui Liu, Min Lin, Haiqiang HuangAbstract:Electrospray ionization multi-stage mass spectrometry (ESI-MS(n)) was performed to study the fragmentation behaviour of seventeen Steroidal Alkaloids (4 protoverine-type Alkaloids, 10 germine-type Alkaloids and 3 zygadenin-type Alkaloids) from the Chinese herb Veratrum nigrum L. The MS(n) spectra of the [M+H](+) ions for Steroidal Alkaloids provided a wealth of structural information on the substituted groups. In positive ion mode, the three types of Alkaloids showed very different characteristic ions: m/z 436 or 418 for protoverine-type Alkaloids; m/z 438, 420 or 402 for germine-type Alkaloids; m/z 440 or 422 for zygadenin-type Alkaloids. These fragments were used to deduce their mass spectral fragmentation mechanisms. Furthermore, the primary compounds in methanolic extracts of the herb of Veratrum nigrum L. were investigated by using liquid chromatography (LC)/ESI-MS(n). As a result, 21 Steroidal Alkaloids (5 protoverine-type Alkaloids, 14 germine-type Alkaloids and 2 zygadenin-type Alkaloids) were selectively identified from 27 determined peaks. Eleven compounds were unambiguously identified by comparing with standard compounds and ten compounds were tentatively identified or deduced according to their MS(n) data. Two of these compounds (xingangermine and deacetyl xinganveratrine) were found to be novel Steroidal Alkaloids. In addition, the chemical structures of two pairs of Steroidal alkaloid isomers were deduced by comparing their fragment ions. Given the important structural information of known and unknown Steroidal Alkaloids in crude herbal extracts, this study is useful for identifying these types of Steroidal Alkaloids in crude materials rapidly and selectively.
Iqbal M Choudhary - One of the best experts on this subject based on the ideXlab platform.
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structure fragmentation relationship and rapid dereplication of buxus Steroidal Alkaloids by electrospray ionization quadrupole time of flight mass spectrometry
Rapid Communications in Mass Spectrometry, 2013Co-Authors: Syed Ghulam Musharraf, Madiha Goher, Salma Shahnaz, Iqbal M ChoudharyAbstract:RATIONALE Tandem mass spectrometric studies of natural products revealed the identification of key fragments which can be helpful for their rapid dereplication in plant extracts utilizing a liquid chromatography/tandem mass spectrometry (LC/MS/MS) approach, particularly for the thermally labile compounds. The knowledge of the collision-induced dissociation (CID) fragmentation pattern of the molecule is essentially required prior to the analysis by LC/MS/MS. METHODS The fragmentation patterns of eleven Buxus Steroidal Alkaloids were studied by using a positive ion electrospray ionization quadrupole time-of-flight mass spectrometry (ESI-QqTOF-MS/MS) hybrid instrument. Chromatographic separation of a Buxus papillosa extract was achieved using a capillary HPLC system coupled with the mass instrument. RESULTS ESI-QqTOF-MS (positive ion mode) showed the presence of several characteristic fragments which can be used to rapidly identify various classes of Buxus Steroidal Alkaloids. The presence of a cyclopropane ring in the cycloartenol skeleton and the hydroxyl group at C-10 was found to effect on the fragmentation pattern and afford characteristic peaks. This study distinguishes between different types of Buxus Steroidal Alkaloids based on logical fragmentation pathways. This strategy was successfully applied in LC/ESI-QqTOF-MS/MS analysis of Buxus papillosa extract to investigate and characterize Buxus Steroidal Alkaloids and 14 compounds were identified as Steroidal Alkaloids. CONCLUSIONS The knowledge of the fragmentation pattern was used for the rapid identification of this bioactive group of biosynthetically unique Steroidal Alkaloids in complex plant extracts of Buxus species, especially in the absence of any reference material, by combining key fragments, exact mass measurements and relative abundances of diagnostic fragment ions.
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rapid characterization and identification of Steroidal Alkaloids in sarcococca coriacea using liquid chromatography coupled with electrospray ionization quadropole time of flight mass spectrometry
Steroids, 2012Co-Authors: Syed Ghulam Musharraf, Madiha Goher, Iqbal M Choudhary, Adnan Ali, Achyut AdhikariAbstract:Rapid characterization of 23 pregnane-type Steroidal Alkaloids was studied using a positive ion electrospray ionization quadropole time-of-flight mass spectrometry (ESI-QqTOF-MS/MS) hybrid instrument. ESI-QqTOF-MS (positive ion mode) showed the presence of the protonated molecules [M+H](+) which through low-energy collision-induced dissociation tandem mass spectrometric (CID-MS/MS) analysis showed the characteristic loss of dimethylamine moiety [M+H-45](+) followed by the sequential lossess of attached substituents. Steroidal Alkaloids having tigloyl or senecioyl group at C-3 produced diagnostic fragment ions at m/z 100 and 83. Our study also demonstrates the influence of unsaturation, and number and nature of substitutents on product ion abundance and fragment ions. Moreover, the generalization of the fragmentation pattern was linked with the structural features in Steroidal skeleton. This strategy was successfully applied in LC-ESI-QqTOF-MS/MS analysis of Sarcococca coriacea extract to investigate and characterize pregnane-type Steroidal Alkaloids in complex mixture.
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structure activity relationship studies on antileishmanial Steroidal Alkaloids from sarcococca hookeriana
Natural Product Research, 2007Co-Authors: Krishna Prasad Devkota, Iqbal M Choudhary, Rosa Ranjit, Norbert SewaldAbstract:The search for antileishmanial constituents from the medicinal plant Sarcococca hookeriana (Buxaceae) of Nepalese origin has resulted in the isolation of 17 (1–17) active Steroidal Alkaloids. Compounds 1, 2, and 10 were subjected to derivatization and five chemically derived derivatives (1a, 2a, 10a, 10b, 10c) were also obtained. All these natural compounds and derivatives were found to have potent to mild antileishmanial properties. The IC50 values were found to be in the range of 0.20–61.44 µg mL−1 (IC50 value of standard drug amphotericin B = 0.12 µg mL−1). The structure activity relationship indicated that the varieties of functionalities present in ring A of the Steroidal Alkaloids were found to play a characteristic role to increase the antileishmanial activity.
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cholinesterase inhibitory pregnane type Steroidal Alkaloids from sarcococca hookeriana
Steroids, 2005Co-Authors: Iqbal M Choudhary, Sarfraz Ahmad Nawaz, Krishna Prasad Devkota, Rosa Ranjit, Atta-ur RahmanAbstract:The bioassay-guided phytochemical investigation on Sarcococca hookeriana have resulted in the isolation of four new pregnane-type steriodal Alkaloids: hookerianamide-D [(2'E,20S)-20-(N,N-formyl(methyl)amino)-3beta-(3',4'-dimethyl-2'-pentenamido)-5alpha-pregnane] (1), hookerianamide-E [(2'E,20S)-20-(N,N-dimethylamino)-3beta-(senecioylamino)-5alpha-pregn-14-en-2beta-O-acetate] (2), hookerianamide-F [(2'E,20S)-20-(N-methylamino)-3beta-(tigloylamino)-5alpha-pregn-2,14-dien-4-one] (3), and hookerianamide-G [(20S)-20-(N,N-dimethylamino)-3beta-(N-methylbenzamido)-5alpha-pregn-4beta-O-acetate] (4), along with five known Alkaloids 5-9. Their structures were determined by spectroscopic analysis. These Steroidal Alkaloids and chemically derived derivatives of compound 5 have displayed varying degree of inhibitory activities against acetylcholinesterase and butyrylcholinesterase enzymes in a concentration-dependent fashion, with the IC(50) values ranging from 1.5 to 148.2 and 0.6 to 100.2 microM, respectively.
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new pregnane type Steroidal Alkaloids from sarcococca saligna and their cholinesterase inhibitory activity
Steroids, 2004Co-Authors: Fareeda Feroz, Sarfraz Ahmad Nawaz, Riaz M Khan, Ismat Naeem, Naeema Khan, Iqbal M ChoudharyAbstract:Five new Steroidal Alkaloids, 5,14-dehydro-N(a)-demethylsaracodine [3beta-N(a)-methyl-20S-N(b)-acetyl-N(b)-methylamino-pregn-5,14-diene] (1), 14-dehydro-N(a)-demethylsaracodine [3beta-N(a)-methyl-20S-N(b)-acetyl-N(b)-methylamino-5alpha-pregn-14-ene] (2), 16-dehydrosarcorine [(20S)-20-(N,N-dimethylamino)-3beta-(N(a)-acetylamido)-5alpha-pregn-16-ene] (3), 2,3-dehydrosarsalignone [(20S)-20-(N,N-dimethylamino)-3beta-(tigloylamino)-pregn-2,5-diene-4-one] (4), and 14,15-dehydrosarcovagine-D [(20S)-20-(N,N-dimethylamino)-3beta-(tigloylamino)-5alpha-pregn-2,14-diene-4-one] (5), were isolated from the ethanolic extract of Sarcococca saligna, along with two known bases, sarcovagenine-C (6) and salignarine-C (7). Their structures were elucidated on the basis of spectroscopic methods. All seven compounds were found to possess cholinesterase inhibitory potential in a concentration-dependent manner with the IC50 values ranging from 12.5 to 200 microM against acetylcholinesterase and from 1.25 to 32.2 microM against butyrylcholinesterase.
Jian Tang - One of the best experts on this subject based on the ideXlab platform.
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simultaneous determination of six Steroidal Alkaloids of veratrum dahuricum by hplc elsd and hplc msn
Chromatographia, 2008Co-Authors: Jian Tang, Weidong Zhang, Yunheng Shen, Runhui Liu, Huizi Jin, Shikai YanAbstract:A high performance liquid chromatography coupled with evaporative light scattering detection (HPLC–ELSD) and electrospray ionization multistage mass spectrometry (HPLC–ESI–MSn), respectively, has been performed for the simultaneous determination of six Steroidal Alkaloids, including pseudojervine, veratrosine, jervine, veratramine, 3-veratroylzygadenine, 3-angeloylzygadenine, in Veratrum dahuricum collected in different seasons. The plants were soaked in methanol and extracted ultrasonically. The six Steroidal Alkaloids were obtained by silica gel column chromatography, eluting with gradient petroleum and acetyl acetate. The intra-day and inter-day precisions of the method were evaluated and were less than 1.4%. The content of Steroidal Alkaloids in the plant varied significantly from spring to autumn, confirming the necessity to control the quality of V. dahuricum during its preparation and application.
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two new Steroidal Alkaloids from veratrum nigrum l
Helvetica Chimica Acta, 2008Co-Authors: Bin Wang, Weidong Zhang, Yunheng Shen, Jian Tang, Chuan Zhang, Runhui Liu, Min LinAbstract:Phytochemical studies on Veratrum nigrum L., collected in Shanxi, P. R. China, resulted in the isolation of two new Steroidal Alkaloids, 23-methoxycyclopamine (1) and 15-O-(2-methylbutanoyl)-3-O-veratroylprotoverine (2). The structures of the two new compounds were established by means of extensive NMR spectroscopic studies.
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characterization and identification of Steroidal Alkaloids in the chinese herb veratrum nigrum l by high performance liquid chromatography electrospray ionization with multi stage mass spectrometry
Rapid Communications in Mass Spectrometry, 2007Co-Authors: Jian Tang, Bin Wang, Weidong Zhang, Chuan Zhang, Runhui Liu, Min Lin, Haiqiang HuangAbstract:Electrospray ionization multi-stage mass spectrometry (ESI-MSn) was performed to study the fragmentation behaviour of seventeen Steroidal Alkaloids (4 protoverine-type Alkaloids, 10 germine-type Alkaloids and 3 zygadenin-type Alkaloids) from the Chinese herb Veratrum nigrum L. The MSn spectra of the [M+H]+ ions for Steroidal Alkaloids provided a wealth of structural information on the substituted groups. In positive ion mode, the three types of Alkaloids showed very different characteristic ions: m/z 436 or 418 for protoverine-type Alkaloids; m/z 438, 420 or 402 for germine-type Alkaloids; m/z 440 or 422 for zygadenin-type Alkaloids. These fragments were used to deduce their mass spectral fragmentation mechanisms. Furthermore, the primary compounds in methanolic extracts of the herb of Veratrum nigrum L. were investigated by using liquid chromatography (LC)/ESI-MSn. As a result, 21 Steroidal Alkaloids (5 protoverine-type Alkaloids, 14 germine-type Alkaloids and 2 zygadenin-type Alkaloids) were selectively identified from 27 determined peaks. Eleven compounds were unambiguously identified by comparing with standard compounds and ten compounds were tentatively identified or deduced according to their MSn data. Two of these compounds (xingangermine and deacetyl xinganveratrine) were found to be novel Steroidal Alkaloids. In addition, the chemical structures of two pairs of Steroidal alkaloid isomers were deduced by comparing their fragment ions. Given the important structural information of known and unknown Steroidal Alkaloids in crude herbal extracts, this study is useful for identifying these types of Steroidal Alkaloids in crude materials rapidly and selectively. Copyright © 2007 John Wiley & Sons, Ltd.
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characterization and identification of Steroidal Alkaloids in the chinese herb veratrum nigrum l by high performance liquid chromatography electrospray ionization with multi stage mass spectrometry
Rapid Communications in Mass Spectrometry, 2007Co-Authors: Jian Tang, Bin Wang, Weidong Zhang, Chuan Zhang, Runhui Liu, Min Lin, Haiqiang HuangAbstract:Electrospray ionization multi-stage mass spectrometry (ESI-MS(n)) was performed to study the fragmentation behaviour of seventeen Steroidal Alkaloids (4 protoverine-type Alkaloids, 10 germine-type Alkaloids and 3 zygadenin-type Alkaloids) from the Chinese herb Veratrum nigrum L. The MS(n) spectra of the [M+H](+) ions for Steroidal Alkaloids provided a wealth of structural information on the substituted groups. In positive ion mode, the three types of Alkaloids showed very different characteristic ions: m/z 436 or 418 for protoverine-type Alkaloids; m/z 438, 420 or 402 for germine-type Alkaloids; m/z 440 or 422 for zygadenin-type Alkaloids. These fragments were used to deduce their mass spectral fragmentation mechanisms. Furthermore, the primary compounds in methanolic extracts of the herb of Veratrum nigrum L. were investigated by using liquid chromatography (LC)/ESI-MS(n). As a result, 21 Steroidal Alkaloids (5 protoverine-type Alkaloids, 14 germine-type Alkaloids and 2 zygadenin-type Alkaloids) were selectively identified from 27 determined peaks. Eleven compounds were unambiguously identified by comparing with standard compounds and ten compounds were tentatively identified or deduced according to their MS(n) data. Two of these compounds (xingangermine and deacetyl xinganveratrine) were found to be novel Steroidal Alkaloids. In addition, the chemical structures of two pairs of Steroidal alkaloid isomers were deduced by comparing their fragment ions. Given the important structural information of known and unknown Steroidal Alkaloids in crude herbal extracts, this study is useful for identifying these types of Steroidal Alkaloids in crude materials rapidly and selectively.
Syed Ghulam Musharraf - One of the best experts on this subject based on the ideXlab platform.
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quantification of Steroidal Alkaloids in buxus papillosa using electrospray ionization liquid chromatography triple quadrupole mass spectrometry
Steroids, 2015Co-Authors: Syed Ghulam Musharraf, Madiha Goher, Bibi ZareenaAbstract:Abstract Buxus papillosa is one of the most extensively studied species of the genus Buxus known to possess Steroidal Alkaloids which can be used for assessing the various pharmacological activities of this plant. This paper describes the liquid chromatography–electrospray ionization triple quadrupole mass spectrometry (LC–ESI-QQQ-MS) method for the quantification of six Steroidal Alkaloids as chemical markers in the extracts of leaves, roots and stems of B. papillosa. Quantitative MS/MS analysis was carried out by optimization of the most sensitive transition for each analyte. This has yielded detection and quantification limits of 0.486–8.08 ng/mL and 1.473–24.268 ng/mL, respectively for all analytes. Linearity of response was also achieved and the regression coefficient found to be >0.99 for all analyzed compounds. The newly developed MRM (Multiple Reaction Monitoring) method showed excellent sensitivity for the quantification of Steroidal Alkaloids within 15 min run time. This paper describes the application of LC–QQQ-MS technique for Steroidal Alkaloids analysis in plant samples.
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structure fragmentation relationship and rapid dereplication of buxus Steroidal Alkaloids by electrospray ionization quadrupole time of flight mass spectrometry
Rapid Communications in Mass Spectrometry, 2013Co-Authors: Syed Ghulam Musharraf, Madiha Goher, Salma Shahnaz, Iqbal M ChoudharyAbstract:RATIONALE Tandem mass spectrometric studies of natural products revealed the identification of key fragments which can be helpful for their rapid dereplication in plant extracts utilizing a liquid chromatography/tandem mass spectrometry (LC/MS/MS) approach, particularly for the thermally labile compounds. The knowledge of the collision-induced dissociation (CID) fragmentation pattern of the molecule is essentially required prior to the analysis by LC/MS/MS. METHODS The fragmentation patterns of eleven Buxus Steroidal Alkaloids were studied by using a positive ion electrospray ionization quadrupole time-of-flight mass spectrometry (ESI-QqTOF-MS/MS) hybrid instrument. Chromatographic separation of a Buxus papillosa extract was achieved using a capillary HPLC system coupled with the mass instrument. RESULTS ESI-QqTOF-MS (positive ion mode) showed the presence of several characteristic fragments which can be used to rapidly identify various classes of Buxus Steroidal Alkaloids. The presence of a cyclopropane ring in the cycloartenol skeleton and the hydroxyl group at C-10 was found to effect on the fragmentation pattern and afford characteristic peaks. This study distinguishes between different types of Buxus Steroidal Alkaloids based on logical fragmentation pathways. This strategy was successfully applied in LC/ESI-QqTOF-MS/MS analysis of Buxus papillosa extract to investigate and characterize Buxus Steroidal Alkaloids and 14 compounds were identified as Steroidal Alkaloids. CONCLUSIONS The knowledge of the fragmentation pattern was used for the rapid identification of this bioactive group of biosynthetically unique Steroidal Alkaloids in complex plant extracts of Buxus species, especially in the absence of any reference material, by combining key fragments, exact mass measurements and relative abundances of diagnostic fragment ions.
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rapid characterization and identification of Steroidal Alkaloids in sarcococca coriacea using liquid chromatography coupled with electrospray ionization quadropole time of flight mass spectrometry
Steroids, 2012Co-Authors: Syed Ghulam Musharraf, Madiha Goher, Iqbal M Choudhary, Adnan Ali, Achyut AdhikariAbstract:Rapid characterization of 23 pregnane-type Steroidal Alkaloids was studied using a positive ion electrospray ionization quadropole time-of-flight mass spectrometry (ESI-QqTOF-MS/MS) hybrid instrument. ESI-QqTOF-MS (positive ion mode) showed the presence of the protonated molecules [M+H](+) which through low-energy collision-induced dissociation tandem mass spectrometric (CID-MS/MS) analysis showed the characteristic loss of dimethylamine moiety [M+H-45](+) followed by the sequential lossess of attached substituents. Steroidal Alkaloids having tigloyl or senecioyl group at C-3 produced diagnostic fragment ions at m/z 100 and 83. Our study also demonstrates the influence of unsaturation, and number and nature of substitutents on product ion abundance and fragment ions. Moreover, the generalization of the fragmentation pattern was linked with the structural features in Steroidal skeleton. This strategy was successfully applied in LC-ESI-QqTOF-MS/MS analysis of Sarcococca coriacea extract to investigate and characterize pregnane-type Steroidal Alkaloids in complex mixture.
Motomasa Kobayashi - One of the best experts on this subject based on the ideXlab platform.
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structure activity relationship and biological property of cortistatins anti angiogenic spongean Steroidal Alkaloids
Bioorganic & Medicinal Chemistry, 2007Co-Authors: Shunji Aoki, Yasuo Watanabe, Daiki Tanabe, Masayoshi Arai, Hideaki Suna, Katsushiro Miyamoto, Hiroshi Tsujibo, Kazutake Tsujikawa, Hiroshi Yamamoto, Motomasa KobayashiAbstract:Abstract Previously, bioassay-guided separation led us to isolate eleven novel Steroidal Alkaloids named cortistatins from the marine sponge Corticium simplex . These cortistatins were classified into three types based on the chemical structure of the side chain part, that is, isoquinoline, N -methyl piperidine or 3-methylpyridine units. From the structure–activity relationship study, the isoquinoline unit in the side chain was found to be crucial for the anti-angiogenic activity of cortistatins. Cortistatin A ( 1 ) showed cytostatic growth-inhibitory activity against human umbilical vein endothelial cells (HUVECs). Cortistatin A ( 1 ) also inhibited VEGF-induced migration of HUVECs and bFGF-induced tubular formation. Although cortistatin A ( 1 ) showed no effect on VEGF-induced phosphorylation of ERK1/2 and p38, which are one of the signaling pathways for migration and tubular formation, the phosphorylation of the unidentified 110 kDa protein in HUVECs was inhibited by the treatment with cortistatin A.
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cortistatins j k l novel abeo 9 10 19 androstane type Steroidal Alkaloids with isoquinoline unit from marine sponge corticium simplex
Tetrahedron Letters, 2007Co-Authors: Shunji Aoki, Yasuo Watanabe, Daiki Tanabe, Andi Setiawan, Masayoshi Arai, Motomasa KobayashiAbstract:Abstract Three novel anti-angiogenic Steroidal Alkaloids, cortistatins J ( 1 ), K ( 2 ), L ( 3 ), have been isolated from the Indonesian marine sponge Corticium simplex . The chemical structures of cortistatins J ( 1 ), K ( 2 ), and L ( 3 ) were determined by 2D-NMR analysis to be unique abeo-9(10-19)-androstane-type Steroidal Alkaloids having isoquinoline unit instead of the side chain part, respectively. Cortistatin J ( 1 ) showed cytostatic anti-proliferative activity against human umbilical vein endothelial cells (HUVECs) at 8 nM, in which the selective index was 300–1000-fold in comparison with other cell lines.
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cortistatins e f g and h four novel Steroidal Alkaloids from marine sponge corticium simplex
Tetrahedron, 2007Co-Authors: Yasuo Watanabe, Shunji Aoki, Daiki Tanabe, Andi Setiawan, Motomasa KobayashiAbstract:Abstract Four novel Steroidal Alkaloids named cortistatins E ( 1 ), F ( 2 ), G ( 3 ), and H ( 4 ) have been isolated from the marine sponge Corticium simplex . The chemical structures of these four cortistatins, which are unique abeo-9(10–19)-stigmastane-type Steroidal Alkaloids having oxabicyclo[3.2.1]octene and N -methyl piperidine or 3-methylpyridine units in the side chain, were elucidated by the detailed 2D-NMR analysis. These four compounds showed only weak anti-proliferative activity against human umbilical vein endothelial cells (HUVECs) at 0.35–1.9 μM concentrations in contrast to cortistatin A ( 5 ), which was isolated as a highly selective inhibitor of proliferation of HUVECs from the same marine sponge.
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cortistatins a b c and d anti angiogenic Steroidal Alkaloids from the marine sponge corticium simplex
Journal of the American Chemical Society, 2006Co-Authors: Shunji Aoki, Naoyuki Kotoku, Yasuo Watanabe, Andi Setiawan, Mami Sanagawa, Motomasa KobayashiAbstract:Four novel Steroidal Alkaloids named cortistatins A (1), B (2), C (3), and D (4) consisting of a 9(10−19)-abeo-androstane and isoquinoline skeleton have been isolated from the marine sponge Corticium simplex. The absolute stereostructures of 1−4 were elucidated by detailed 2D NMR, CD, and X-ray crystallographic analyses. Cortistatins A−D inhibited proliferation of human umbilical vein endothelial cells (HUVECs) with high selectivity. Among the four substances, cortistatin A (1) showed the strongest anti-proliferative activity (IC50 = 0.0018 μM) against HUVECs, in which the selective index was more than 3000-fold in comparison with that of normal fibroblast or several tumor cell lines.
