The Experts below are selected from a list of 3786 Experts worldwide ranked by ideXlab platform
Véronique Cheynier - One of the best experts on this subject based on the ideXlab platform.
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A-type proanthocyanidins from pericarp of Litchi Chinensis
Phytochemistry, 1998Co-Authors: Erwan Le Roux, Thierry Doco, Pascale Sarni-manchado, Yves Lozano, Véronique CheynierAbstract:Abstract A tannin extract was isolated from freeze-dried Litchi pericarp (Litchi Chinensis). HPLC analysis, after thioacidolysis reaction, revealed that this tannin fraction consisted of epicatechin units linked by both A- and B-type interflavonoid bonds. The calculated average degree of polymerization, considering the presence of A-type linkages, was 6.4. Characterization of oligomeric and polymeric procyanidins was performed using electrospray ionization mass spectrometry. Numerous oligomers containing one or more A-type interflavanoid linkages were detected. A regular repartition of the number of A-type linkages for each polymer length (e.g. from 2 to 7 for DP17 with mostly 4 A-type linkages) was observed. The average number of A-type linkages also increased with the DP, the predominant species containing one A-type linkage (denoted 1A) from DP2 to 5, 2A from DP6 to 10, 3A from DP11 to 15 and 4A from DP16 to 20. The highest DP was estimated at 22, with predominantly 5–6 A-type interflavanoid linkages.
Xiaoyun Xu - One of the best experts on this subject based on the ideXlab platform.
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a type procyanidins from Litchi Chinensis pericarp with antioxidant activity
Food Chemistry, 2007Co-Authors: Erning Yang, Xiaoyun XuAbstract:Abstract The main oligomeric procyanidins from Litchi pericarp (Litchi Chinensis) were isolated and identified. Complete assignment of epicatechin-(4β→8, 2β→O→7)-epicatechin-(4β→8)-epicatechin structure was obtained using CD, NMR and ESI-MS techniques. The known (−)-epicatechin and procyanidin A2 were also isolated from Litchi pericarp. The effects of oligomeric procyanidins, A2 and epicatechin-(4β→8, 2β→O→7)-epicatechin-(4β→8)-epicatechin from Litchi pericarp on free radical-scavenging were determined by using a chemiluminescent method. The results showed that all of them had a strong scavenging effect on OH, and the IC50 values were 2.60 μg/ml, 1.75 μg/ml and 1.65 μg/ml for oligomeric procyanidins, A2 and the trimeric procyanidins, respectively. The antioxidant activities of A-type dimeric and trimeric procyanidins seemed to be related to the number of hydroxyls in their molecular structures.
Erwan Le Roux - One of the best experts on this subject based on the ideXlab platform.
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A-type proanthocyanidins from pericarp of Litchi Chinensis
Phytochemistry, 1998Co-Authors: Erwan Le Roux, Thierry Doco, Pascale Sarni-manchado, Yves Lozano, Véronique CheynierAbstract:Abstract A tannin extract was isolated from freeze-dried Litchi pericarp (Litchi Chinensis). HPLC analysis, after thioacidolysis reaction, revealed that this tannin fraction consisted of epicatechin units linked by both A- and B-type interflavonoid bonds. The calculated average degree of polymerization, considering the presence of A-type linkages, was 6.4. Characterization of oligomeric and polymeric procyanidins was performed using electrospray ionization mass spectrometry. Numerous oligomers containing one or more A-type interflavanoid linkages were detected. A regular repartition of the number of A-type linkages for each polymer length (e.g. from 2 to 7 for DP17 with mostly 4 A-type linkages) was observed. The average number of A-type linkages also increased with the DP, the predominant species containing one A-type linkage (denoted 1A) from DP2 to 5, 2A from DP6 to 10, 3A from DP11 to 15 and 4A from DP16 to 20. The highest DP was estimated at 22, with predominantly 5–6 A-type interflavanoid linkages.
Wu Xingrong - One of the best experts on this subject based on the ideXlab platform.
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Development and characterization of SSR markers in lychee (Litchi Chinensis)
Molecular Ecology Notes, 2006Co-Authors: Li Mingfang, Zheng Xueqing, Zhu Yongqiang, Wang Xiangshe, Liang Suyu, Li Lei, Wu XingrongAbstract:Sixteen microsatellite loci were isolated from lychee (Litchi Chinensis), all of which exhibited polymorphism (two or three alleles per locus), with levels of heterozygosity ranging from 0.021 to 0.900. These loci can help assess the genetic structure of lychee.
Erning Yang - One of the best experts on this subject based on the ideXlab platform.
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a type procyanidins from Litchi Chinensis pericarp with antioxidant activity
Food Chemistry, 2007Co-Authors: Erning Yang, Xiaoyun XuAbstract:Abstract The main oligomeric procyanidins from Litchi pericarp (Litchi Chinensis) were isolated and identified. Complete assignment of epicatechin-(4β→8, 2β→O→7)-epicatechin-(4β→8)-epicatechin structure was obtained using CD, NMR and ESI-MS techniques. The known (−)-epicatechin and procyanidin A2 were also isolated from Litchi pericarp. The effects of oligomeric procyanidins, A2 and epicatechin-(4β→8, 2β→O→7)-epicatechin-(4β→8)-epicatechin from Litchi pericarp on free radical-scavenging were determined by using a chemiluminescent method. The results showed that all of them had a strong scavenging effect on OH, and the IC50 values were 2.60 μg/ml, 1.75 μg/ml and 1.65 μg/ml for oligomeric procyanidins, A2 and the trimeric procyanidins, respectively. The antioxidant activities of A-type dimeric and trimeric procyanidins seemed to be related to the number of hydroxyls in their molecular structures.