Dual linker

This dual linker approach allowed selective cleavage of the peptide from the dendrimer using 1% TFA/CH2CI2 without cleaving the dendrimer from the resin. Proceeding from the TentaGel resin the final product was obtained in 44% yield... 

McKeown, S.C. Watson, S.P. Carr, R.A.E. Marshall, P.A. Photolabile Carbamate Based Dual Linker Analytical Construct for Facile Monitoring of Solid Phase Chemistry TLC for Solid Phase Tetrahedron Lett. 40, 2407-2410 (1999). 

Williams, G.M. Carr, R.A.E. Congreve, M.S. Kay, C. McKeown, S.C. Murray, P.J. Scicinski, J.J. Watson, S.P. Analysis of Solid-phase Reactions Product Identification and Quantification by Use of UV-Chromophore-Containing Dual-Linker Analytical Constructs, Angew. Chem., Intern. Ed. Eng. 39, 3293-3296 (2000). 

One of the most time-consuming steps in synthesis on solid supports is the adaptation and optimization of reaction conditions. Furthermore, the optimization process is difficult to monitor on the solid support. Magic-angle spinning NMR (MAS) or FT-IR can be used, but these are technically very demanding. A possible solution is the concept of dual linkers involving an analytical unit [200]. These can be employed not only to optimize chemical reactions on a support, but also for quality control of the compound libraries. The basic principle is outlined in Fig. 15. 

A simple alternative dual linker system with a reference cleavage site has recently been reported for the optimization of reaction conditions for solid-phase chemistry [208]. The principle is outlined in Fig. 19. 

Soften and render products more flexible by reduction of the brittleness of the end-product. Also used to modify viscosity and improve the flow characteristics and processability of a polymer. Are designed to space out the polymer molecules, facilitating their movements and leading to enhanced flexibility (lower modulus) and ductility. Plasticisers may play a dual role as stabilisers or cross-linkers. Performance criteria are compatibility, plasticising efficiency, processability and permanence. 

Fig- 2. The two-stage release ofpeptides from iminodiacetic acid-based dual cleavable linker. 

Incorporating common structural motifs such as the His-and Cys-containing motifs and the zinc finger domain discussed above onto other proteins has resulted in new hybrid proteins with dual functionality. Two strategies have been used to achieve this goal. In the first strategy, the metalbinding motifs or domains are fused by a linker to either the N-... 

Electrochemically controlled SAMs of the alkanethiol class characterized to high voltammetric resolution and to molecular and sub-molecular structural in situ STM resolution have been reviewed recently [60, 151]. We note here first some issues of importance to functionalized alkanethiols as linker molecules for gentle immobilization of fully functional redox metalloprotein monolayers on singlecrystal Au(lll) electrode surfaces. We discuss next specifically the functionalized alkanethiols cysteine (Cys) and homocysteine (Hey). These two molecules represent a core protein building block and a core metabolite, respectively. The former has been used to display unique sub-molecular in situ STM resolution [152]. The latter shows a unique dual surface dynamics pattern that could be followed both by single-molecule in situ STM and by high-resolution capacitive voltammetry. 

Nitric oxide-releasing NSAlDs, such as NO-aspirin 50 (NCX-4016) and the ibuprofen derivative 51, contain a cleavable ester linker to a nitric oxide-releasing moiety (Figure 27.12). It was hoped that this dual activity would translate into a superior anti-inflammatory and antithrombotic profile in patients with cardiovascular diseases, whilst sparing the gastrointestinal tract. 

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