The structure of Cs RESi O , where RE=Dy-Lu, Y, In, is unusual in that it contains octahedrally coordinated rare-earth ions; their relative orientation dictates the structure, as they rotate about the c-axis supported by the cyclic Si O framework. The repeat unit of the rotation is eight units generating a very long (ca. 57 Å) unit cell axis.
View Article and Find Full Text PDFOrthogonal protection of amino acid side chains in solid phase peptide synthesis allows for selective deprotection of side chains and the formation of cyclic peptides on resin. Cyclizations are useful as they may improve the activity of the peptide or improve the metabolic stability of peptides in vivo. One cyclization method often used is the formation of a lactam bridge between an amine and a carboxylic acid.
View Article and Find Full Text PDFDeltorphins are naturally occurring peptides produced by the skin of the giant monkey frog (Phyllomedusa bicolor). They are δ-opioid receptor-selective agonists. Herein, we report the design and synthesis of a peptide, Tyr-d-Ala-(pI)Phe-Glu-Ile-Ile-Gly-NH2 3 (GATE3-8), based on the [d-Ala(2)]deltorphin II template, which is δ-selective in in vitro radioligand binding assays over the μ- and κ-opioid receptors.
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