Application of the Anomeric Samarium Route for the Convergent Synthesis of the C-Linked Trisaccharide α-d-Man-(1→3)-[α-d-Man-(1→6)]-d-Man and the Disaccharides α-d-Man-(1→3)-d-Man and α-d-Man-(1→6)-d-Man
摘要:
Studies are reported on the assembly of the branched C-trisaccharide, alpha-D-Man-(1-->3)-[alpha-D-Man-(1-->6)]-D-Man, representing the core region of the asparagine-linked oligosaccharides. The key step in this synthesis uses a SmI2-mediated coupling of two mannosylpyridyl sulfones to a C3,C6-diformyl branched monosaccharide unit, thereby assembling all three sugar units in one reaction and with complete stereocontrol at the two anomeric carbon centers. Subsequent tin hydride-based deoxygenation followed by a deprotection step produces the target C-trimer. In contrast to many of the other C-glycosylation methods, this approach employes intact carbohydrate units as C-glycosyl donors and acceptors, which in many instances parallels the well-studied O-glycosylation reactions. The synthesis of the C-disaccharides alpha-D-Man-(1-->3)-D-Man and alpha-D-Man-(1-->6)-D-Man is also described, they being necessary for the following conformational studies of all three carbohydrate analogues both in solution and bound to several mannose-binding proteins.
gambierol analogues have been prepared from an advanced intermediate of our totalsynthesis of gambierol and investigated for their toxicity against mice, thus providing the first systematic structure-activity relationships (SAR) of this polycyclic ether class of marine toxin. The SAR studies described herein clearly indicate that 1) the C28=C29 double bond within the H ring and the unsaturated side chain
NOVELCROSSLINKING REAGENTS, MACROMOLECULES, THERAPEUTIC CONJUGATES, AND SYNTHETIC METHODS THEREOF
申请人:CellMosaic, Inc.
公开号:US20140206903A1
公开(公告)日:2014-07-24
The invention provides novel chemical entities based on sugar alcohols. These new chemical entities are biocompatible and biodegradable. The molecules can be made in a single and pure form. The molecular weights of these molecules range from small (<1000 Da) to large (1000-120,000 Da). The sugar alcohol-based molecules can have functional groups throughout the molecule for crosslinking compounds, such as the preparation of antibody-drug conjugates, or to facilitate the delivery of therapeutic proteins, peptides, siRNA, and chemotherapeutic drugs. Also provided are new conjugate entities prepared through sugar alcohol molecules. Methods of synthesizing sugar alcohol-based molecules and conjugates are also within the scope of the invention.
Laccase is considered a potential target in the field of agriculturalfungicides. To promote the discovery and development of compounds with laccase inhibitory activity, herein, taking reported laccase inhibitor 4-chlorocinnamaldehyde thiosemicarbazide (PMDD-5Y) as the lead compound, two series of 29 novel Schiff-base compounds were designed and synthesized by introducing natural structural unit 1
The synthesis of a new analogue of (+/-)-huperzine A lacking the ethylidene appendage at position ii has been accomplished. The key steps of the synthesis were: a) the reduction of the keto function of the known methyl 7.7-ethylenedioxy-3-methyl-9-oxobicyclo[3.3.1]non-3-ene-1 -carboxylate into a methylene group by reduction to a mixture of stereoisomeric alcohols followed by alcohol-deoxygenation through a Barton-McCombie procedure and b) the elaboration of the pyridone ring in a late stage of the synthesis by reaction of a pyrrolidine enamine with propiolamide, which gave a mixture of regioisomeric pyridone derivatives. (C) 1999 Elsevier Science Ltd. All rights reserved.
NOVEL CROSSLINKING REAGENTS, MACROMOLECULES, THERAPEUTIC BIOCONJUGATES, AND SYNTHETIC METHODS THEREOF
申请人:CellMosaic, Inc.
公开号:US20170065726A1
公开(公告)日:2017-03-09
The invention provides novel chemical entities based on sugar alcohols. These new chemical entities are biocompatible and biodegradable. The molecules can be made in a single and pure form. The molecular weights of these molecules range from small (<1000 Da) to large (1000-120,000 Da). The sugar alcohol-based molecules can have functional groups throughout the molecule for crosslinking compounds, such as the preparation of antibody-drug conjugates, or to facilitate the delivery of therapeutic proteins, peptides, siRNA, and chemotherapeutic drugs. Also provided are new conjugate entities prepared through sugar alcohol molecules. Methods of synthesizing sugar alcohol-based molecules and conjugates are also within the scope of the invention.