Results 51 to 60 of about 13,012 (246)

The Unusual Bifunctional Catalysis of Epimerization and Desaturation by Carbapenem Synthase [PDF]

, 2016
High-level ab initio calculations have been used to study the mechanism for the conversion of (3S,5S)-carbapenam to the biologically active β-lactam antibiotic, (5R)-carbapenem, catalyzed by carbapenem synthase.
Christopher J. Schofield (233097), Christopher J. Easton (1574488), Maya Topf (689468), David M. Smith (155808), Gregory M. Sandala (1333143), Leo Radom (1485967)   +5 more
core   +1 more source

Toward the Synthesis of Pestalustaine A: Structural Revision and Formation of Original Strained Tricyclic Architectures

Angewandte Chemie, EarlyView.
Our synthetic endeavor toward the total synthesis of the reported unprecedented tricyclic skeleton of the sesquiterpene pestalustaine A allowed us to perform divergent cyclizations of a bicyclo[4.4.1]undec‐3‐ene into complex tricyclic architectures and to revise the structure of the natural product.
Wei Cao, Alicia Ross, Jean‐Pierre Baltaze, Régis Guillot, Menglin Xu, Rongzhen Qin, Bingcheng Yang, Isabel Wong, Katayoon Formul, Cyrille Kouklovsky, Dean J. Tantillo, Vincent Gandon, Guillaume Vincent   +12 more
wiley   +2 more sources

Water, Alcohols, Amines, and Amides as Formal Hydrogen‐Atom‐Transfer Reagents Through Activation With Redox‐Active Lewis Acids

Angewandte Chemie, EarlyView.
Protic molecules containing strong O─H or N─H bonds typically resist hydrogen‐atom abstraction because of the high reactivity of the resulting heteroatom‐centered radicals. However, association of the protic molecules with redox‐active Lewis acids can provide powerful hydrogen‐atom donors or proton‐coupled‐electron‐transfer reagents.
Petra Vojáčková, Armido Studer
wiley   +2 more sources

Detoxification of Deoxynivalenol by a Mixed Culture of Soil Bacteria With 3-epi-Deoxynivalenol as the Main Intermediate

Frontiers in Microbiology, 2019
Deoxynivalenol (DON) is a widely distributed mycotoxin that frequently occurs in various agricultural raw materials and feeds. DON acts as a virulence factor that accelerates the spread of plant diseases; moreover, its accumulation in grains causes yield
Yaoyao Zhai, Lei Zhong, Hui Gao, Zhaoxin Lu, Xiaomei Bie, Haizhen Zhao, Chong Zhang, Fengxia Lu   +7 more
doaj   +1 more source

Structure of lasso peptide epimerase MslH reveals metal-dependent acid/base catalytic mechanism

Nature Communications, 2023
The lasso peptide MS-271 is a ribosomally synthesized and post-translationally modified peptide (RiPP) consisting of 21 amino acids with D-tryptophan at the C-terminus, and is derived from the precursor peptide MslA.
Yu Nakashima, Atsushi Kawakami, Yasushi Ogasawara, Masatoshi Maeki, Manabu Tokeshi, Tohru Dairi, Hiroyuki Morita   +6 more
doaj   +1 more source

Structural insights and therapeutic targets in Acinetobacter baumannii capsule biosynthesis

FEBS Letters, EarlyView.
Hypervirulent KL49 A. baumannii's capsular polysaccharide contains the nonulosonic acid 8‐epi‐Leg5,7Ac2, synthesized by epimerization via ElaA, ElaB, and ElaC. Crystal structures of ElaA, ElaB, and ElaC reveal their role in CMP‐Leg5,7Ac2 synthesis and regioselective C8 epimerization.
Woo Cheol Lee, Junho Jeong, Chae Yeong Lee, Hyunjoon Cho, Man Hwan Oh, Je Chul Lee, Jee‐Young Lee, Yangmee Kim   +7 more
wiley   +1 more source

Phosphate-catalyzed epimerization of N-acetyl-d-glucosamine to N-acetyl-d-mannosamine for the synthesis of N-acetylneuraminic acid [PDF]

, 2017
Phosphate-catalyzed epimerization of N-acetyl-d-glucosamine to N-acetyl-d-mannosamine is reported in this study. The epimerization of N-acetyl-d-glucosamine was found to be facilitated by proton acceptors via the deprotonation of the amide group.
Dai, Shenghong A, Lin, Sung-Chyr, Lin, Meng-Kai, Chen, Chun-Fan, 林松池   +4 more
core   +1 more source

Tall fescue seed extraction and partial purification of ergot alkaloids

Frontiers in Chemistry, 2014
Many substances in the tall fescue/endophyte association (Schedonorus arundinaceus/Epichloë coenophiala) have biological activity. Of these compounds only the ergot alkaloids are known to have significant mammalian toxicity and the predominant ergot ...
Lowell eBush
doaj   +1 more source

Cobalt‐Catalyzed Asymmetric Construction of Boron Stereocenters With C–N Axial Chirality

Advanced Science, EarlyView.
A cobalt/Salox‐catalyzed one‐pot annulation enables enantioselective formation of B‐stereogenic centers and C─N axial chirality via C─H/N─H annulation, affording diverse fluorescent products with high stereocontrol and optoelectronic potential. ABSTRACT The efficient construction of boron stereogenic centers alongside axial chirality remains a ...
Subramani Kumaran, Harihara Subramanian Ravi Sankar, Pritam Maity, J. Richard Premkumar, Abir Das, Basker Sundararaju   +5 more
wiley   +1 more source

Borylcyclopropanes: Synthetic Strategies and Applications

Angewandte Chemie, EarlyView.
Borylcyclopropanes (cyclopropanes bearing a boron substituent) sit at the intersection of two privileged frameworks in synthesis. This review provides the first exhaustive survey of their chemistry, spanning metal–carbene, nucleophilic cyclization, radical, hydroboration, and C─H activation routes, and documenting applications in medicinal chemistry ...
Aiza A. Butt, Joseph M. Ready
wiley   +2 more sources