The Experts below are selected from a list of 174 Experts worldwide ranked by ideXlab platform
Jose Luis Cabrera - One of the best experts on this subject based on the ideXlab platform.
-
alkaloid profiling and anticholinesterase activity of south american lycopodiaceae species
Journal of Enzyme Inhibition and Medicinal Chemistry, 2013Co-Authors: Eduardo Luis Konrath, Maria Gabriela Ortega, Jose Luis Cabrera, Sergio De Loreto Bordignon, Miriam Anders Apel, Amelia T HenriquesAbstract:The alkaloid extracts of four Huperzia and one Lycopodiella species, from Brazilian habitats, were tested for their in vitro anticholinesterase activities. IC(50) values showed a potent acetylcholinesterase inhibition for H. reflexa (0.11 ± 0.05 μg/mL), followed by H. quadrifariata (2.0 ± 0.3 μg/mL), H. acerosa (5.5 ± 0.9 μg/mL), H. heterocarpon (25.6 ± 2.7 μg/mL) and L. cernua (42.6 ± 1.5 μg/mL). A lower inhibition of butyrylcholinesterase was observed for all species with the exception of H. heterocarpon (8.3 ± 0.9 μg/mL), whose alkaloid extract presented a selectivity for pseudocholinesterase. Moreover, the chemical study of the bioactive extracts performed by GC-MS, revealed the presence of a number of Lycopodium alkaloids belonging to the lycopodane, flabellidane and cernuane groups. Surprisingly, the potent acetylcholinesterase inhibitors huperzines A and B were not detected in the extracts, suggesting that other alkaloids may be responsible for such an effect.
-
anticholinesterase activity in an alkaloid extract of huperzia saururus
Phytomedicine, 2004Co-Authors: Maria Gabriela Ortega, Alicia Mariel Agnese, Jose Luis CabreraAbstract:Abstract Huperzia saururus (Lam.) Trevis. (Lycopodiaceae) is used widely in Argentinian traditional medicine as an aphrodisiac and for memory improvement. An aqueous extract from the aerial parts was obtained by decoction, revealing the presence of alkaloids, among other constituents. By partition with organic solvent in alkaline media, alkaloids were extracted and then purified by gel permeation. We studied the anticholinesterase activity in vitro of the alkaloid extract using erythrocyte membranes and human serum as sources of acetylcholinesterase and pseudocholinesterase, respectively. The results show a marked inhibition of true acetylcholinesterase with an IC 50 value of 0.58 μg/ml. Low inhibition of pseudocholinesterase was observed (IC 50 value=191 μg/ml). This shows a selectivity of the extract for the true acetylcholinesterase. Furthermore, chemical study of the bioactive extract was performed by GC-MS, revealing the presence of seven Lycopodium alkaloids, including some not identified previously: sauroxine, 6-hydroxyLycopodine, N -acetyllycodine, Lycopodine, lycodine, N -methyllycodine, and clavolonine. Further investigations will be undertaken in order to discover which compound/s are responsible for the aqueous extract's acetylcholinesterase activity.
Jinfeng Hu - One of the best experts on this subject based on the ideXlab platform.
-
annotinolide f and lycoannotines a i further lycopodium alkaloids from lycopodium annotinum
Phytochemistry, 2017Co-Authors: Yu Tang, Juan Xiong, Haiyan Zhang, Wei Wang, Chao Huang, Jinfeng HuAbstract:Abstract Seven Lycopodine-type (annotinolide F and lycoannotines A–F), two lycodine-type (lycoannotines G and H), and one fawcettimine-type (lycoannotine I) previously undescribed naturally occurring Lycopodium alkaloids together with thirteen known ones were isolated from the whole plant of Lycopodium annotinum. Their structures and absolute configurations were determined by extensive spectroscopic methods, single-crystal X-ray diffraction, chemical transformation, and electronic circular dichroism (ECD) calculations. Among the isolates, annotinolide F, lycoannotines A and B are unusual 7,8-seco-lycopodane derivatives, and annotinolide F even further possesses a rare 8,5-lactone framework through a lactonization after the C-7/C-8 bond cleavage. Lycoannotine C is an uncommon 8,15-seco Lycopodine-type alkaloid, whereas lycoannotine I represents the first example of a naturally occurring C-9/N bond cleavage product of fawcettimine-type alkaloid. Among them, only lycoannotine I was found to show considerable anti-butyrylcholinesterase (anti-BuChE) activity.
-
palhicerines a f lycopodium alkaloids from the club moss palhinhaea cernua
Phytochemistry, 2016Co-Authors: Yu Tang, Juan Xiong, Haiyan Zhang, Jinfeng HuAbstract:Four fawcettimine-type (palhicerines A–D, resp.) and two Lycopodine-type (palhicerines E and F) Lycopodium alkaloids together with twenty known ones were isolated from the whole plant of Palhinhaea cernua. The structures and absolute configurations of the palhicerines A–F were determined by extensive spectroscopic methods, single-crystal X-ray diffraction analyses, chemical transformation, and electronic circular dichroism (ECD) calculations or induced electronic circular dichroism (IECD) spectra. Among the isolates, the new C/D-ring of the palhicerines A–C (trans-fused fawcettimine-type alkaloids) are rare, and each possesses a β-oriented C-16 methyl group and a distinctive tertiary methoxy group at C-13. Chemotaxonomy for differentiating species in the genus Palhinhaea is briefly discussed.
-
annotinolides a c three lycopodane derived 8 5 lactones with polycyclic skeletons from lycopodium annotinum
Organic Letters, 2016Co-Authors: Yu Tang, Juan Xiong, Haiyan Zhang, Wei Wang, Jingjing Zhang, Jinfeng HuAbstract:Three novel 7,8-seco-lycopodane-derived 8,5-lactones (annotinolides A–C, 1–3) were isolated from Lycopodium annotinum. Their structures were elucidated by spectroscopic methods and single-crystal X-ray diffraction. Compound 1 possesses an unusual cyclopropane ring constructed through a hitherto unknown C-6/C-12 bond. Compound 2 represents the first 7,8-seco-lycopodane-derived alkaloid with a rare cyclobutane ring formed by a new C-12/C-15 linkage, while the C-8/C-15 bond remains. Compound 3 contains an unprecedented 12-spiro-9,12-γ-lactone moiety. Their plausible biosynthetic pathways and antiaggregation effects on amyloid-β1–42 are also presented.
Juan Xiong - One of the best experts on this subject based on the ideXlab platform.
-
lycofargesiines a f further lycopodium alkaloids from the club moss huperzia fargesii
Phytochemistry, 2019Co-Authors: Juan Xiong, Haiyan Zhang, Weijia Meng, Yike Zou, Wenxuan Wang, Xinyi Wang, Qilian Yang, Ezzat E A OsmanAbstract:Abstract Six undescribed Lycopodium alkaloids (LAs) comprising four lycodine-type (lycofargesiines A–D), one Lycopodine-type (lycofargesiine E), and a phlegmarine-type (lycofargesiine F), together with 16 known ones were isolated from the club moss Huperzia fargesii. Their structures and absolute configurations were determined by extensive spectroscopic methods, electronic circular dichroism (ECD) analysis, and density functional theory (DFT) calculations. (7S,8R,12R,13R)-Lycofargesiine A is a rare naturally occurring LA possessing an exocyclic double bond between C-15 and C-16, with ring A being a rare 2,3-dihyropyridone motif. Lycofargesiine D is an uncommon lycodine-type alkaloid featuring a unique N-acetylated tetrahydropyridinyl segment (ring A), whereas lycofargesiine F is the first phlegmarane-type LA bearing two nitrone moieties. In addition to the isolated huperzine A in this study, another two isolates (lycofargesiine C and 16-hydroxyhuperzine A) were also found to show inhibitory activities against acetylcholinesterase (AChE), with IC50 values of 8.63 and 5.18 μM, respectively.
-
annotinolide f and lycoannotines a i further lycopodium alkaloids from lycopodium annotinum
Phytochemistry, 2017Co-Authors: Yu Tang, Juan Xiong, Haiyan Zhang, Wei Wang, Chao Huang, Jinfeng HuAbstract:Abstract Seven Lycopodine-type (annotinolide F and lycoannotines A–F), two lycodine-type (lycoannotines G and H), and one fawcettimine-type (lycoannotine I) previously undescribed naturally occurring Lycopodium alkaloids together with thirteen known ones were isolated from the whole plant of Lycopodium annotinum. Their structures and absolute configurations were determined by extensive spectroscopic methods, single-crystal X-ray diffraction, chemical transformation, and electronic circular dichroism (ECD) calculations. Among the isolates, annotinolide F, lycoannotines A and B are unusual 7,8-seco-lycopodane derivatives, and annotinolide F even further possesses a rare 8,5-lactone framework through a lactonization after the C-7/C-8 bond cleavage. Lycoannotine C is an uncommon 8,15-seco Lycopodine-type alkaloid, whereas lycoannotine I represents the first example of a naturally occurring C-9/N bond cleavage product of fawcettimine-type alkaloid. Among them, only lycoannotine I was found to show considerable anti-butyrylcholinesterase (anti-BuChE) activity.
-
palhicerines a f lycopodium alkaloids from the club moss palhinhaea cernua
Phytochemistry, 2016Co-Authors: Yu Tang, Juan Xiong, Haiyan Zhang, Jinfeng HuAbstract:Four fawcettimine-type (palhicerines A–D, resp.) and two Lycopodine-type (palhicerines E and F) Lycopodium alkaloids together with twenty known ones were isolated from the whole plant of Palhinhaea cernua. The structures and absolute configurations of the palhicerines A–F were determined by extensive spectroscopic methods, single-crystal X-ray diffraction analyses, chemical transformation, and electronic circular dichroism (ECD) calculations or induced electronic circular dichroism (IECD) spectra. Among the isolates, the new C/D-ring of the palhicerines A–C (trans-fused fawcettimine-type alkaloids) are rare, and each possesses a β-oriented C-16 methyl group and a distinctive tertiary methoxy group at C-13. Chemotaxonomy for differentiating species in the genus Palhinhaea is briefly discussed.
-
annotinolides a c three lycopodane derived 8 5 lactones with polycyclic skeletons from lycopodium annotinum
Organic Letters, 2016Co-Authors: Yu Tang, Juan Xiong, Haiyan Zhang, Wei Wang, Jingjing Zhang, Jinfeng HuAbstract:Three novel 7,8-seco-lycopodane-derived 8,5-lactones (annotinolides A–C, 1–3) were isolated from Lycopodium annotinum. Their structures were elucidated by spectroscopic methods and single-crystal X-ray diffraction. Compound 1 possesses an unusual cyclopropane ring constructed through a hitherto unknown C-6/C-12 bond. Compound 2 represents the first 7,8-seco-lycopodane-derived alkaloid with a rare cyclobutane ring formed by a new C-12/C-15 linkage, while the C-8/C-15 bond remains. Compound 3 contains an unprecedented 12-spiro-9,12-γ-lactone moiety. Their plausible biosynthetic pathways and antiaggregation effects on amyloid-β1–42 are also presented.
-
Annotinolides A–C, Three Lycopodane-Derived 8,5-Lactones with Polycyclic Skeletons from Lycopodium annotinum
2016Co-Authors: Yu Tang, Juan Xiong, Wei Wang, Jingjing Zhang, Haiyan ZhangAbstract:Three novel 7,8-seco-lycopodane-derived 8,5-lactones (annotinolides A–C, 1–3) were isolated from Lycopodium annotinum. Their structures were elucidated by spectroscopic methods and single-crystal X-ray diffraction. Compound 1 possesses an unusual cyclopropane ring constructed through a hitherto unknown C-6/C-12 bond. Compound 2 represents the first 7,8-seco-lycopodane-derived alkaloid with a rare cyclobutane ring formed by a new C-12/C-15 linkage, while the C-8/C-15 bond remains. Compound 3 contains an unprecedented 12-spiro-9,12-γ-lactone moiety. Their plausible biosynthetic pathways and antiaggregation effects on amyloid-β1–42 are also presented
Haiyan Zhang - One of the best experts on this subject based on the ideXlab platform.
-
lycofargesiines a f further lycopodium alkaloids from the club moss huperzia fargesii
Phytochemistry, 2019Co-Authors: Juan Xiong, Haiyan Zhang, Weijia Meng, Yike Zou, Wenxuan Wang, Xinyi Wang, Qilian Yang, Ezzat E A OsmanAbstract:Abstract Six undescribed Lycopodium alkaloids (LAs) comprising four lycodine-type (lycofargesiines A–D), one Lycopodine-type (lycofargesiine E), and a phlegmarine-type (lycofargesiine F), together with 16 known ones were isolated from the club moss Huperzia fargesii. Their structures and absolute configurations were determined by extensive spectroscopic methods, electronic circular dichroism (ECD) analysis, and density functional theory (DFT) calculations. (7S,8R,12R,13R)-Lycofargesiine A is a rare naturally occurring LA possessing an exocyclic double bond between C-15 and C-16, with ring A being a rare 2,3-dihyropyridone motif. Lycofargesiine D is an uncommon lycodine-type alkaloid featuring a unique N-acetylated tetrahydropyridinyl segment (ring A), whereas lycofargesiine F is the first phlegmarane-type LA bearing two nitrone moieties. In addition to the isolated huperzine A in this study, another two isolates (lycofargesiine C and 16-hydroxyhuperzine A) were also found to show inhibitory activities against acetylcholinesterase (AChE), with IC50 values of 8.63 and 5.18 μM, respectively.
-
annotinolide f and lycoannotines a i further lycopodium alkaloids from lycopodium annotinum
Phytochemistry, 2017Co-Authors: Yu Tang, Juan Xiong, Haiyan Zhang, Wei Wang, Chao Huang, Jinfeng HuAbstract:Abstract Seven Lycopodine-type (annotinolide F and lycoannotines A–F), two lycodine-type (lycoannotines G and H), and one fawcettimine-type (lycoannotine I) previously undescribed naturally occurring Lycopodium alkaloids together with thirteen known ones were isolated from the whole plant of Lycopodium annotinum. Their structures and absolute configurations were determined by extensive spectroscopic methods, single-crystal X-ray diffraction, chemical transformation, and electronic circular dichroism (ECD) calculations. Among the isolates, annotinolide F, lycoannotines A and B are unusual 7,8-seco-lycopodane derivatives, and annotinolide F even further possesses a rare 8,5-lactone framework through a lactonization after the C-7/C-8 bond cleavage. Lycoannotine C is an uncommon 8,15-seco Lycopodine-type alkaloid, whereas lycoannotine I represents the first example of a naturally occurring C-9/N bond cleavage product of fawcettimine-type alkaloid. Among them, only lycoannotine I was found to show considerable anti-butyrylcholinesterase (anti-BuChE) activity.
-
palhicerines a f lycopodium alkaloids from the club moss palhinhaea cernua
Phytochemistry, 2016Co-Authors: Yu Tang, Juan Xiong, Haiyan Zhang, Jinfeng HuAbstract:Four fawcettimine-type (palhicerines A–D, resp.) and two Lycopodine-type (palhicerines E and F) Lycopodium alkaloids together with twenty known ones were isolated from the whole plant of Palhinhaea cernua. The structures and absolute configurations of the palhicerines A–F were determined by extensive spectroscopic methods, single-crystal X-ray diffraction analyses, chemical transformation, and electronic circular dichroism (ECD) calculations or induced electronic circular dichroism (IECD) spectra. Among the isolates, the new C/D-ring of the palhicerines A–C (trans-fused fawcettimine-type alkaloids) are rare, and each possesses a β-oriented C-16 methyl group and a distinctive tertiary methoxy group at C-13. Chemotaxonomy for differentiating species in the genus Palhinhaea is briefly discussed.
-
annotinolides a c three lycopodane derived 8 5 lactones with polycyclic skeletons from lycopodium annotinum
Organic Letters, 2016Co-Authors: Yu Tang, Juan Xiong, Haiyan Zhang, Wei Wang, Jingjing Zhang, Jinfeng HuAbstract:Three novel 7,8-seco-lycopodane-derived 8,5-lactones (annotinolides A–C, 1–3) were isolated from Lycopodium annotinum. Their structures were elucidated by spectroscopic methods and single-crystal X-ray diffraction. Compound 1 possesses an unusual cyclopropane ring constructed through a hitherto unknown C-6/C-12 bond. Compound 2 represents the first 7,8-seco-lycopodane-derived alkaloid with a rare cyclobutane ring formed by a new C-12/C-15 linkage, while the C-8/C-15 bond remains. Compound 3 contains an unprecedented 12-spiro-9,12-γ-lactone moiety. Their plausible biosynthetic pathways and antiaggregation effects on amyloid-β1–42 are also presented.
-
Annotinolides A–C, Three Lycopodane-Derived 8,5-Lactones with Polycyclic Skeletons from Lycopodium annotinum
2016Co-Authors: Yu Tang, Juan Xiong, Wei Wang, Jingjing Zhang, Haiyan ZhangAbstract:Three novel 7,8-seco-lycopodane-derived 8,5-lactones (annotinolides A–C, 1–3) were isolated from Lycopodium annotinum. Their structures were elucidated by spectroscopic methods and single-crystal X-ray diffraction. Compound 1 possesses an unusual cyclopropane ring constructed through a hitherto unknown C-6/C-12 bond. Compound 2 represents the first 7,8-seco-lycopodane-derived alkaloid with a rare cyclobutane ring formed by a new C-12/C-15 linkage, while the C-8/C-15 bond remains. Compound 3 contains an unprecedented 12-spiro-9,12-γ-lactone moiety. Their plausible biosynthetic pathways and antiaggregation effects on amyloid-β1–42 are also presented
Maria Gabriela Ortega - One of the best experts on this subject based on the ideXlab platform.
-
alkaloid profiling and anticholinesterase activity of south american lycopodiaceae species
Journal of Enzyme Inhibition and Medicinal Chemistry, 2013Co-Authors: Eduardo Luis Konrath, Maria Gabriela Ortega, Jose Luis Cabrera, Sergio De Loreto Bordignon, Miriam Anders Apel, Amelia T HenriquesAbstract:The alkaloid extracts of four Huperzia and one Lycopodiella species, from Brazilian habitats, were tested for their in vitro anticholinesterase activities. IC(50) values showed a potent acetylcholinesterase inhibition for H. reflexa (0.11 ± 0.05 μg/mL), followed by H. quadrifariata (2.0 ± 0.3 μg/mL), H. acerosa (5.5 ± 0.9 μg/mL), H. heterocarpon (25.6 ± 2.7 μg/mL) and L. cernua (42.6 ± 1.5 μg/mL). A lower inhibition of butyrylcholinesterase was observed for all species with the exception of H. heterocarpon (8.3 ± 0.9 μg/mL), whose alkaloid extract presented a selectivity for pseudocholinesterase. Moreover, the chemical study of the bioactive extracts performed by GC-MS, revealed the presence of a number of Lycopodium alkaloids belonging to the lycopodane, flabellidane and cernuane groups. Surprisingly, the potent acetylcholinesterase inhibitors huperzines A and B were not detected in the extracts, suggesting that other alkaloids may be responsible for such an effect.
-
anticholinesterase activity in an alkaloid extract of huperzia saururus
Phytomedicine, 2004Co-Authors: Maria Gabriela Ortega, Alicia Mariel Agnese, Jose Luis CabreraAbstract:Abstract Huperzia saururus (Lam.) Trevis. (Lycopodiaceae) is used widely in Argentinian traditional medicine as an aphrodisiac and for memory improvement. An aqueous extract from the aerial parts was obtained by decoction, revealing the presence of alkaloids, among other constituents. By partition with organic solvent in alkaline media, alkaloids were extracted and then purified by gel permeation. We studied the anticholinesterase activity in vitro of the alkaloid extract using erythrocyte membranes and human serum as sources of acetylcholinesterase and pseudocholinesterase, respectively. The results show a marked inhibition of true acetylcholinesterase with an IC 50 value of 0.58 μg/ml. Low inhibition of pseudocholinesterase was observed (IC 50 value=191 μg/ml). This shows a selectivity of the extract for the true acetylcholinesterase. Furthermore, chemical study of the bioactive extract was performed by GC-MS, revealing the presence of seven Lycopodium alkaloids, including some not identified previously: sauroxine, 6-hydroxyLycopodine, N -acetyllycodine, Lycopodine, lycodine, N -methyllycodine, and clavolonine. Further investigations will be undertaken in order to discover which compound/s are responsible for the aqueous extract's acetylcholinesterase activity.
