Results 41 to 50 of about 13,012 (246)

Advances in the chemistry, pharmacological diversity, and metabolism of 20(R)-ginseng saponins

Journal of Ginseng Research, 2020
Ginseng has been used as a popular herbal medicine in East Asia for at least two millennia. However, 20(R)-ginseng saponins, one class of important rare ginsenosides, are rare in natural products. 20(R)-ginseng saponins are generally prepared by chemical
Chaoming Wang, Juan Liu, Jianqiang Deng, Jiazhen Wang, Weizhao Weng, Hongxia Chu, Qingguo Meng   +6 more
doaj   +1 more source

De Novo Discovery of Nonstandard Thioisoindole‐Bridged Bicyclic Peptides Targeting Traf2‐ and NCK‐Interacting Kinase

Angewandte Chemie, EarlyView.
An optimized strategy for the ribosomal synthesis of thioisoindole‐bridged bicyclic (TiB) peptides is incorporated into the RaPID platform, enabling high‐throughput discovery from topologically defined TiB libraries. Proof‐of‐concept selection against TNIK identifies nanomolar‐affinity ligands with inhibitory activity, while x‐ray crystallography ...
Yue Zhang, Alexander A. Vinogradov, Keisuke Hamada, Yin Sun, Toru Sengoku, Hiroaki Suga   +5 more
wiley   +2 more sources

Effect of cyclodextrins on the thermal epimerization of tea catechins [PDF]

, 2008
The epimerization reaction of tea catechins was investigated at pH 5.5 and 120°C in the absence/presence of cyclodextrins (CDs). In the absence of CDs, a considerable quantity (∼20%) of products originating from reactions other than the epimerization ...
10998, 10997, 10242538, 10999, Ichitani, Masaki, 604, Okumura, Hisako, Kunimoto, Ko-Ki, Takihara, Takanobu   +8 more
core   +2 more sources

Polymetallic Molybdenum-Based Catalysts for Epimerization of Glucose to Mannose [PDF]

, 2022
Molybdenum-based catalysts have been widely studied in the epimerization of glucose to mannose. In this paper, several polymetallic molybdenum-based catalysts were prepared and the high activity and selectivity of catalysts containing different divalent ...
Sun, Ying, Hu, Xiangping, Peng, Fubin, Hua, Chao, Wang, Xinhong, Ma, Hong, Zhang, Meiyun, Liu, Xin, Bai, Fang   +8 more
core   +1 more source

Structural and Functional Siderophore Remodeling by Enzymatic Delipidation

Angewandte Chemie, EarlyView.
A surprising functional switch in bacterial siderophores was discovered through genome mining and the analysis of environmental and pathogenic Pandoraea species. Pandorachelin B, a lipocyclopeptide that promotes swarming motility, is cleaved by a specialized acylase, yielding a ring‐contracted, homodetic cyclopeptide, pandorachelin A, which exhibits ...
Elena Herzog, Keishi Ishida, Evelyn M. Molloy, Ron Hermenau, Kirstin Scherlach, Christian Hertweck   +5 more
wiley   +2 more sources

Contribution of the 7β-hydroxysteroid dehydrogenase from Ruminococcus gnavus N53 to ursodeoxycholic acid formation in the human colon[S]

Journal of Lipid Research, 2013
Bile acid composition in the colon is determined by bile acid flow in the intestines, the population of bile acid-converting bacteria, and the properties of the responsible bacterial enzymes.
Ja-Young Lee, Hisashi Arai, Yusuke Nakamura, Satoru Fukiya, Masaru Wada, Atsushi Yokota   +5 more
doaj   +1 more source

Chemoenzymatic Synthesis of Heparan Sulfate Oligosaccharides by a Covalent Catch‐and‐Release Approach

Angewandte Chemie, EarlyView.
A glycan having a hydrazide tag enables chemoenzymatic synthesis of HS oligosaccharides. The hydrazide can, under mild acidic conditions, react with an aldehyde‐containing resin to give an immobilized hydrazone that is stable under neutral conditions, allowing washing. The product can be released by transiminolysis using aqueous hydroxylamine to give a
Francesco Palmieri, Chin Huang, Digantkumar Chapla, Kelley W. Moremen, Geert‐Jan Boons   +4 more
wiley   +2 more sources

Epimerization of Glycal Derivatives by a Cyclopentadienylruthenium Catalyst : Application to Metalloenzymatic DYKAT [PDF]

, 2014
Epimerization of a non-anomeric stereogenic center in carbohydrates is an important transformation in the synthesis of natural products. In this study an epimerization procedure of the allylic alcohols of glycals by cyclopentadienylruthenium catalyst 1 ...
Bäckvall, Jan-Erling, Jan‐E. Bäckvall, Lihammar, Richard,, Widmalm, Göran,, Göran Widmalm, Richard Lihammar, Jerk Rönnols, Rönnols, Jerk,, Bäckvall, Jan-Erling,, Rönnols, Jerk, Widmalm, Göran, Lihammar, Richard   +11 more
core   +1 more source

Harnessing the Reactivity of Sulfinate Salts With Cystine: An Umpolung Approach to Residue‐Specific Peptide Modification

Angewandte Chemie, EarlyView.
While cysteine is widely employed as a nucleophilic handle for peptide modification, the electrophilicity of the oxidized form, cystine, is rarely exploited. This study describes a mild, photochemical coupling of sulfinate salts with peptide disulfides.
Joshua M. Hammond, Esteban Suárez‐Picado, Lena von Sydow, Hanna Bruss, Laurent Knerr, Magnus Johansson, Anaïs Noisier, Lara R. Malins   +7 more
wiley   +2 more sources

Expression of Key Structural Genes of the Phenylpropanoid Pathway Associated with Catechin Epimerization in Tea Cultivars

Frontiers in Plant Science, 2017
Catechin epimerization is an important factor affecting tea catechin compositions and thereby tea quality. However, a lack of tea germplasms with high non-epicatechins limits relative research.
Changsong Chen, Kang Wei, Liyuan Wang, Li Ruan, Hailin Li, Xiaogui Zhou, Zhenghe Lin, Ruiyang Shan, Hao Cheng   +8 more
doaj   +1 more source