The Experts below are selected from a list of 5619 Experts worldwide ranked by ideXlab platform
Yonglin Huang - One of the best experts on this subject based on the ideXlab platform.
-
phytochemical and chemotaxonomic study on Castanopsis fargesii franch
Biochemical Systematics and Ecology, 2018Co-Authors: Yafeng Wang, Ruijie He, Dianpeng Li, Yonglin HuangAbstract:Abstract In the course of a phytochemical and chemotaxonomical investigation for the Castanopsis (Fagaceae) species, fifteen compounds, including two triterpene hexahydroxydiphenoyl esters (1 and 2), seven gallotannins (3–9), three flavonoids (10–12), and three other compounds (13–15) were isolated from the leaves of Castanopsis fargesii Franch. Their structures were elucidated by means of spectroscopic methods and in comparison with published data. All these compounds were obtained from this species for the first time. Moreover, ethyl glucopyranoside (15) was firstly isolated from the genus Castanopsis. 6-O-Galloyl-β- d -glucose (3) and 3,4′,5,7-tetrahydroxyflavone (11) have not been reported from any species in Fagaceae family. The chemotaxonomic significance of these compounds was summarized.
-
phenolic compounds from the leaves of Castanopsis fargesii
Molecules, 2017Co-Authors: Yonglin Huang, Yafeng Wang, Takashi Tanaka, Lei Wang, Yueyuan Chen, Fenglai Lu, Dianpeng LiAbstract:In the course of a phytochemical and chemotaxonomical investigation of Castanopsis species (Fagaceae), three new phenolic compounds, (3R,1′S)-[1′-(6″-O-galloyl-β-d-gluco-pyranosyl)oxyethyl]-3-hydroxy-dihydrofuran-2(3H)-one (1), (2R,3S)-2-[2′-(galloyl)oxyethyl]-dihydroxybutanoic acid (2), and (3S,4S)-3-hydroxymethyl-3,4-dihydro-5,6,7-trihydroxy-4-(4′-hydroxy-3′-methoxyphenyl)-1H-[2]-benzopyran-1-one (3) were isolated from the fresh leaves of Castanopsis fargesii. In addition, a known phenolic glycoside, gentisic acid 5-O-α-l-rhamnopyranosyl-(1→2)-β-d-glucopyranoside (4) was also isolated and identified. Their structures were elucidated by means of spectroscopic methods including one- and two-dimensional NMR techniques.
-
isolation of ellagitannin monomer and macrocyclic dimer from Castanopsis carlesii leaves
ChemInform, 2013Co-Authors: Yonglin Huang, Dianpeng Li, Yosuke Matsuo, Takashi Tanaka, Isao Kouno, Genichiro NonakaAbstract:Monomeric ellagitannin named carlesiin A (I) and its macrocyclic dimer are isolated from leaves of Castanopsis carlesii.
-
two new phenolic glucosides and an ellagitannin from the leaves of Castanopsis sclerophylla
Phytochemistry Letters, 2012Co-Authors: Yonglin Huang, Dianpeng Li, Yosuke Matsuo, Takashi Tanaka, Isao Kouno, Genichiro NonakaAbstract:Abstract In the course of a chemotaxonomical study of Castanopsis species (Fagaceae), detailed investigation of the leaves of C. sclerophylla led to isolation of three new phenolic compounds together with 62 known compounds. The structures of the new compounds were elucidated as 2-O-galloyl-O-4,6-(S)-valoneoyl- d -glucose (1), 6-O-galloyl-1-O-vanilloyl-β- d -glucose (2), and 4″-O-galloylchestanin (3) by means of spectroscopic analyses and enzymatic hydrolysis with tannase. Comparison with other Castanopsis species indicated that C. sclerophylla characteristically accumulates chlorogenic acid and a dimeric ellagitannin, rugosin E. Triterpene hexahydroxydiphenoyl esters, which are major constituents of C. cuspidata var. sieboldii, C. hystrix, and C. fissa were not detected.
-
new phenylpropanoid substituted flavan 3 ols from the leaves of Castanopsis sclerophylla
ChemInform, 2012Co-Authors: Yonglin Huang, Dianpeng Li, Yosuke Matsuo, Takashi Tanaka, Isao Kouno, Genichiro NonakaAbstract:The chemotaxonomical study of Castanopsis species leads to the isolation of two previously unknown flavanols.
Genichiro Nonaka - One of the best experts on this subject based on the ideXlab platform.
-
isolation of ellagitannin monomer and macrocyclic dimer from Castanopsis carlesii leaves
ChemInform, 2013Co-Authors: Yonglin Huang, Dianpeng Li, Yosuke Matsuo, Takashi Tanaka, Isao Kouno, Genichiro NonakaAbstract:Monomeric ellagitannin named carlesiin A (I) and its macrocyclic dimer are isolated from leaves of Castanopsis carlesii.
-
two new phenolic glucosides and an ellagitannin from the leaves of Castanopsis sclerophylla
Phytochemistry Letters, 2012Co-Authors: Yonglin Huang, Dianpeng Li, Yosuke Matsuo, Takashi Tanaka, Isao Kouno, Genichiro NonakaAbstract:Abstract In the course of a chemotaxonomical study of Castanopsis species (Fagaceae), detailed investigation of the leaves of C. sclerophylla led to isolation of three new phenolic compounds together with 62 known compounds. The structures of the new compounds were elucidated as 2-O-galloyl-O-4,6-(S)-valoneoyl- d -glucose (1), 6-O-galloyl-1-O-vanilloyl-β- d -glucose (2), and 4″-O-galloylchestanin (3) by means of spectroscopic analyses and enzymatic hydrolysis with tannase. Comparison with other Castanopsis species indicated that C. sclerophylla characteristically accumulates chlorogenic acid and a dimeric ellagitannin, rugosin E. Triterpene hexahydroxydiphenoyl esters, which are major constituents of C. cuspidata var. sieboldii, C. hystrix, and C. fissa were not detected.
-
new phenylpropanoid substituted flavan 3 ols from the leaves of Castanopsis sclerophylla
ChemInform, 2012Co-Authors: Yonglin Huang, Dianpeng Li, Yosuke Matsuo, Takashi Tanaka, Isao Kouno, Genichiro NonakaAbstract:The chemotaxonomical study of Castanopsis species leads to the isolation of two previously unknown flavanols.
-
triterpene hexahydroxydiphenoyl esters and a quinic acid purpurogallin carbonyl ester from the leaves of Castanopsis fissa
Phytochemistry, 2011Co-Authors: Dianpeng Li, Yonglin Huang, Yosuke Matsuo, Takashi Tanaka, Isao Kouno, Takaaki Tsujita, Genichiro NonakaAbstract:Triterpene hexahydroxydiphenoyl (HHDP) esters have only been isolated from Castanopsis species, and the distribution of these esters in nature is of chemotaxonomical interest. In this study, the chemical constituents of the leaves of Castanopsis fissa were examined in detail to identify and isolate potential HHDP esters. Together with 53 known compounds, 3,4-di-O-galloyl-1-O-purpurogallin carbonyl quinic acid (1) and 3,24-(S)-HHDP-2α,3β,23,24-tetrahydroxytaraxastan-28,20β-olide (2) were isolated and their structures were elucidated by spectroscopic and chemical methods. The polyphenols of the leaves were mainly composed of galloyl quinic acids, triterpenes HHDP esters, ellagitannins and flavonol glycosides. In particular, the isolation yields of 1,3,4-trigalloyl quinic acid and compound 2 were 1.53% and 0.27%, respectively, from the fresh leaves. The presence of lipid soluble HHDP esters of oleanane-type triterpenes as one of the major metabolites is an important chemotaxonomical discovery. Lipase inhibition activities and ORAC values of the major constituents were compared. The triterpene HHDP ester showed moderate lipase inhibition activity and myricitrin gave the largest ORAC value.
-
new phenylpropanoid substituted flavan 3 ols from the leaves of Castanopsis sclerophylla
Heterocycles, 2011Co-Authors: Takashi Tanaka, Dianpeng Li, Yonglin Huang, Yosuke Matsuo, Isao Kouno, Genichiro NonakaAbstract:In the course of a chemotaxonomical study of Chinese Castanopsis species, two previously unknown flavan-3-ols, named sclerophynins A and B, were isolated from the leaves of C. sclerophylla, together with five related known compounds. On the basis of spectroscopic analysis, the new compounds were characterized to be (4S,8R,9S)-4-(3,4-dihydroxyphenyl)-8-(3,4, 5-trihydroxyphenyl)-3,4,9,10-tetra-hydro-5,9-dihydroxy-2H,8H-benzo[1,2-b:3,4-b']dipyran-2one and (4S,7S,8R)-4,8-bis(3,4-dihydroxyphenyl)-3,4,6,7-tetrahydro-5-glucopyranosyloxy-7-hydroxy-2H,8H-benzo[1,2-b:5,4-b']dipyran-2-one, respectively. The genus Castanopsis belongs to the family Fagaceae and contains approximately 120 species. Over 50 species have been recorded in East Asia, many of which are important as ornamental trees and for use as construction materials. Seeds of some species are edible and the leaves and bark have been used medicinally. Despite the large number of species, however, few chemotaxonomical studies have been performed. Previously, characteristic triterpene hexahydroxydiphenoyl (HHDP) esters were isolated from the leaves of C. cuspidata var. sieboldii and C. hystrix. The triterpene HHDP esters have been found only in these Castanopsis species and have been shown to have chemotaxonomical significance. Thus, we began a phytochemical study of the phenolic constituents of the Chinese Castanopsis species. C. sclerophylla is an evergreen tree distributed throughout Southern China. The leaves and seeds are rich in tannins and are used for the treatment of hemorrhage, chronic ulcers and diarrhea. Our preliminary analysis, using HPLC and TLC, indicated that the leaves do not contain triterpene HHDP esters. It did, however, reveal the presence of unusual flavan-3-ols. This paper presents the structure determination of two previously unknown compounds.
Dianpeng Li - One of the best experts on this subject based on the ideXlab platform.
-
phytochemical and chemotaxonomic study on Castanopsis fargesii franch
Biochemical Systematics and Ecology, 2018Co-Authors: Yafeng Wang, Ruijie He, Dianpeng Li, Yonglin HuangAbstract:Abstract In the course of a phytochemical and chemotaxonomical investigation for the Castanopsis (Fagaceae) species, fifteen compounds, including two triterpene hexahydroxydiphenoyl esters (1 and 2), seven gallotannins (3–9), three flavonoids (10–12), and three other compounds (13–15) were isolated from the leaves of Castanopsis fargesii Franch. Their structures were elucidated by means of spectroscopic methods and in comparison with published data. All these compounds were obtained from this species for the first time. Moreover, ethyl glucopyranoside (15) was firstly isolated from the genus Castanopsis. 6-O-Galloyl-β- d -glucose (3) and 3,4′,5,7-tetrahydroxyflavone (11) have not been reported from any species in Fagaceae family. The chemotaxonomic significance of these compounds was summarized.
-
phenolic compounds from the leaves of Castanopsis fargesii
Molecules, 2017Co-Authors: Yonglin Huang, Yafeng Wang, Takashi Tanaka, Lei Wang, Yueyuan Chen, Fenglai Lu, Dianpeng LiAbstract:In the course of a phytochemical and chemotaxonomical investigation of Castanopsis species (Fagaceae), three new phenolic compounds, (3R,1′S)-[1′-(6″-O-galloyl-β-d-gluco-pyranosyl)oxyethyl]-3-hydroxy-dihydrofuran-2(3H)-one (1), (2R,3S)-2-[2′-(galloyl)oxyethyl]-dihydroxybutanoic acid (2), and (3S,4S)-3-hydroxymethyl-3,4-dihydro-5,6,7-trihydroxy-4-(4′-hydroxy-3′-methoxyphenyl)-1H-[2]-benzopyran-1-one (3) were isolated from the fresh leaves of Castanopsis fargesii. In addition, a known phenolic glycoside, gentisic acid 5-O-α-l-rhamnopyranosyl-(1→2)-β-d-glucopyranoside (4) was also isolated and identified. Their structures were elucidated by means of spectroscopic methods including one- and two-dimensional NMR techniques.
-
isolation of ellagitannin monomer and macrocyclic dimer from Castanopsis carlesii leaves
ChemInform, 2013Co-Authors: Yonglin Huang, Dianpeng Li, Yosuke Matsuo, Takashi Tanaka, Isao Kouno, Genichiro NonakaAbstract:Monomeric ellagitannin named carlesiin A (I) and its macrocyclic dimer are isolated from leaves of Castanopsis carlesii.
-
two new phenolic glucosides and an ellagitannin from the leaves of Castanopsis sclerophylla
Phytochemistry Letters, 2012Co-Authors: Yonglin Huang, Dianpeng Li, Yosuke Matsuo, Takashi Tanaka, Isao Kouno, Genichiro NonakaAbstract:Abstract In the course of a chemotaxonomical study of Castanopsis species (Fagaceae), detailed investigation of the leaves of C. sclerophylla led to isolation of three new phenolic compounds together with 62 known compounds. The structures of the new compounds were elucidated as 2-O-galloyl-O-4,6-(S)-valoneoyl- d -glucose (1), 6-O-galloyl-1-O-vanilloyl-β- d -glucose (2), and 4″-O-galloylchestanin (3) by means of spectroscopic analyses and enzymatic hydrolysis with tannase. Comparison with other Castanopsis species indicated that C. sclerophylla characteristically accumulates chlorogenic acid and a dimeric ellagitannin, rugosin E. Triterpene hexahydroxydiphenoyl esters, which are major constituents of C. cuspidata var. sieboldii, C. hystrix, and C. fissa were not detected.
-
new phenylpropanoid substituted flavan 3 ols from the leaves of Castanopsis sclerophylla
ChemInform, 2012Co-Authors: Yonglin Huang, Dianpeng Li, Yosuke Matsuo, Takashi Tanaka, Isao Kouno, Genichiro NonakaAbstract:The chemotaxonomical study of Castanopsis species leads to the isolation of two previously unknown flavanols.
Takashi Tanaka - One of the best experts on this subject based on the ideXlab platform.
-
phenolic compounds from the leaves of Castanopsis fargesii
Molecules, 2017Co-Authors: Yonglin Huang, Yafeng Wang, Takashi Tanaka, Lei Wang, Yueyuan Chen, Fenglai Lu, Dianpeng LiAbstract:In the course of a phytochemical and chemotaxonomical investigation of Castanopsis species (Fagaceae), three new phenolic compounds, (3R,1′S)-[1′-(6″-O-galloyl-β-d-gluco-pyranosyl)oxyethyl]-3-hydroxy-dihydrofuran-2(3H)-one (1), (2R,3S)-2-[2′-(galloyl)oxyethyl]-dihydroxybutanoic acid (2), and (3S,4S)-3-hydroxymethyl-3,4-dihydro-5,6,7-trihydroxy-4-(4′-hydroxy-3′-methoxyphenyl)-1H-[2]-benzopyran-1-one (3) were isolated from the fresh leaves of Castanopsis fargesii. In addition, a known phenolic glycoside, gentisic acid 5-O-α-l-rhamnopyranosyl-(1→2)-β-d-glucopyranoside (4) was also isolated and identified. Their structures were elucidated by means of spectroscopic methods including one- and two-dimensional NMR techniques.
-
isolation of ellagitannin monomer and macrocyclic dimer from Castanopsis carlesii leaves
ChemInform, 2013Co-Authors: Yonglin Huang, Dianpeng Li, Yosuke Matsuo, Takashi Tanaka, Isao Kouno, Genichiro NonakaAbstract:Monomeric ellagitannin named carlesiin A (I) and its macrocyclic dimer are isolated from leaves of Castanopsis carlesii.
-
two new phenolic glucosides and an ellagitannin from the leaves of Castanopsis sclerophylla
Phytochemistry Letters, 2012Co-Authors: Yonglin Huang, Dianpeng Li, Yosuke Matsuo, Takashi Tanaka, Isao Kouno, Genichiro NonakaAbstract:Abstract In the course of a chemotaxonomical study of Castanopsis species (Fagaceae), detailed investigation of the leaves of C. sclerophylla led to isolation of three new phenolic compounds together with 62 known compounds. The structures of the new compounds were elucidated as 2-O-galloyl-O-4,6-(S)-valoneoyl- d -glucose (1), 6-O-galloyl-1-O-vanilloyl-β- d -glucose (2), and 4″-O-galloylchestanin (3) by means of spectroscopic analyses and enzymatic hydrolysis with tannase. Comparison with other Castanopsis species indicated that C. sclerophylla characteristically accumulates chlorogenic acid and a dimeric ellagitannin, rugosin E. Triterpene hexahydroxydiphenoyl esters, which are major constituents of C. cuspidata var. sieboldii, C. hystrix, and C. fissa were not detected.
-
new phenylpropanoid substituted flavan 3 ols from the leaves of Castanopsis sclerophylla
ChemInform, 2012Co-Authors: Yonglin Huang, Dianpeng Li, Yosuke Matsuo, Takashi Tanaka, Isao Kouno, Genichiro NonakaAbstract:The chemotaxonomical study of Castanopsis species leads to the isolation of two previously unknown flavanols.
-
triterpene hexahydroxydiphenoyl esters and a quinic acid purpurogallin carbonyl ester from the leaves of Castanopsis fissa
Phytochemistry, 2011Co-Authors: Dianpeng Li, Yonglin Huang, Yosuke Matsuo, Takashi Tanaka, Isao Kouno, Takaaki Tsujita, Genichiro NonakaAbstract:Triterpene hexahydroxydiphenoyl (HHDP) esters have only been isolated from Castanopsis species, and the distribution of these esters in nature is of chemotaxonomical interest. In this study, the chemical constituents of the leaves of Castanopsis fissa were examined in detail to identify and isolate potential HHDP esters. Together with 53 known compounds, 3,4-di-O-galloyl-1-O-purpurogallin carbonyl quinic acid (1) and 3,24-(S)-HHDP-2α,3β,23,24-tetrahydroxytaraxastan-28,20β-olide (2) were isolated and their structures were elucidated by spectroscopic and chemical methods. The polyphenols of the leaves were mainly composed of galloyl quinic acids, triterpenes HHDP esters, ellagitannins and flavonol glycosides. In particular, the isolation yields of 1,3,4-trigalloyl quinic acid and compound 2 were 1.53% and 0.27%, respectively, from the fresh leaves. The presence of lipid soluble HHDP esters of oleanane-type triterpenes as one of the major metabolites is an important chemotaxonomical discovery. Lipase inhibition activities and ORAC values of the major constituents were compared. The triterpene HHDP ester showed moderate lipase inhibition activity and myricitrin gave the largest ORAC value.
Yosuke Matsuo - One of the best experts on this subject based on the ideXlab platform.
-
isolation of ellagitannin monomer and macrocyclic dimer from Castanopsis carlesii leaves
ChemInform, 2013Co-Authors: Yonglin Huang, Dianpeng Li, Yosuke Matsuo, Takashi Tanaka, Isao Kouno, Genichiro NonakaAbstract:Monomeric ellagitannin named carlesiin A (I) and its macrocyclic dimer are isolated from leaves of Castanopsis carlesii.
-
two new phenolic glucosides and an ellagitannin from the leaves of Castanopsis sclerophylla
Phytochemistry Letters, 2012Co-Authors: Yonglin Huang, Dianpeng Li, Yosuke Matsuo, Takashi Tanaka, Isao Kouno, Genichiro NonakaAbstract:Abstract In the course of a chemotaxonomical study of Castanopsis species (Fagaceae), detailed investigation of the leaves of C. sclerophylla led to isolation of three new phenolic compounds together with 62 known compounds. The structures of the new compounds were elucidated as 2-O-galloyl-O-4,6-(S)-valoneoyl- d -glucose (1), 6-O-galloyl-1-O-vanilloyl-β- d -glucose (2), and 4″-O-galloylchestanin (3) by means of spectroscopic analyses and enzymatic hydrolysis with tannase. Comparison with other Castanopsis species indicated that C. sclerophylla characteristically accumulates chlorogenic acid and a dimeric ellagitannin, rugosin E. Triterpene hexahydroxydiphenoyl esters, which are major constituents of C. cuspidata var. sieboldii, C. hystrix, and C. fissa were not detected.
-
new phenylpropanoid substituted flavan 3 ols from the leaves of Castanopsis sclerophylla
ChemInform, 2012Co-Authors: Yonglin Huang, Dianpeng Li, Yosuke Matsuo, Takashi Tanaka, Isao Kouno, Genichiro NonakaAbstract:The chemotaxonomical study of Castanopsis species leads to the isolation of two previously unknown flavanols.
-
triterpene hexahydroxydiphenoyl esters and a quinic acid purpurogallin carbonyl ester from the leaves of Castanopsis fissa
Phytochemistry, 2011Co-Authors: Dianpeng Li, Yonglin Huang, Yosuke Matsuo, Takashi Tanaka, Isao Kouno, Takaaki Tsujita, Genichiro NonakaAbstract:Triterpene hexahydroxydiphenoyl (HHDP) esters have only been isolated from Castanopsis species, and the distribution of these esters in nature is of chemotaxonomical interest. In this study, the chemical constituents of the leaves of Castanopsis fissa were examined in detail to identify and isolate potential HHDP esters. Together with 53 known compounds, 3,4-di-O-galloyl-1-O-purpurogallin carbonyl quinic acid (1) and 3,24-(S)-HHDP-2α,3β,23,24-tetrahydroxytaraxastan-28,20β-olide (2) were isolated and their structures were elucidated by spectroscopic and chemical methods. The polyphenols of the leaves were mainly composed of galloyl quinic acids, triterpenes HHDP esters, ellagitannins and flavonol glycosides. In particular, the isolation yields of 1,3,4-trigalloyl quinic acid and compound 2 were 1.53% and 0.27%, respectively, from the fresh leaves. The presence of lipid soluble HHDP esters of oleanane-type triterpenes as one of the major metabolites is an important chemotaxonomical discovery. Lipase inhibition activities and ORAC values of the major constituents were compared. The triterpene HHDP ester showed moderate lipase inhibition activity and myricitrin gave the largest ORAC value.
-
new phenylpropanoid substituted flavan 3 ols from the leaves of Castanopsis sclerophylla
Heterocycles, 2011Co-Authors: Takashi Tanaka, Dianpeng Li, Yonglin Huang, Yosuke Matsuo, Isao Kouno, Genichiro NonakaAbstract:In the course of a chemotaxonomical study of Chinese Castanopsis species, two previously unknown flavan-3-ols, named sclerophynins A and B, were isolated from the leaves of C. sclerophylla, together with five related known compounds. On the basis of spectroscopic analysis, the new compounds were characterized to be (4S,8R,9S)-4-(3,4-dihydroxyphenyl)-8-(3,4, 5-trihydroxyphenyl)-3,4,9,10-tetra-hydro-5,9-dihydroxy-2H,8H-benzo[1,2-b:3,4-b']dipyran-2one and (4S,7S,8R)-4,8-bis(3,4-dihydroxyphenyl)-3,4,6,7-tetrahydro-5-glucopyranosyloxy-7-hydroxy-2H,8H-benzo[1,2-b:5,4-b']dipyran-2-one, respectively. The genus Castanopsis belongs to the family Fagaceae and contains approximately 120 species. Over 50 species have been recorded in East Asia, many of which are important as ornamental trees and for use as construction materials. Seeds of some species are edible and the leaves and bark have been used medicinally. Despite the large number of species, however, few chemotaxonomical studies have been performed. Previously, characteristic triterpene hexahydroxydiphenoyl (HHDP) esters were isolated from the leaves of C. cuspidata var. sieboldii and C. hystrix. The triterpene HHDP esters have been found only in these Castanopsis species and have been shown to have chemotaxonomical significance. Thus, we began a phytochemical study of the phenolic constituents of the Chinese Castanopsis species. C. sclerophylla is an evergreen tree distributed throughout Southern China. The leaves and seeds are rich in tannins and are used for the treatment of hemorrhage, chronic ulcers and diarrhea. Our preliminary analysis, using HPLC and TLC, indicated that the leaves do not contain triterpene HHDP esters. It did, however, reveal the presence of unusual flavan-3-ols. This paper presents the structure determination of two previously unknown compounds.