5420-88-2Relevant academic research and scientific papers
From solution to in-cell study of the chemical reactivity of acid sensitive functional groups: A rational approach towards improved cleavable linkers for biospecific endosomal release
Jacques, Sylvain A.,Leriche, Geoffray,Mosser, Michel,Nothisen, Marc,Muller, Christian D.,Remy, Jean-Serge,Wagner, Alain
supporting information, p. 4794 - 4803 (2016/06/13)
pH-Sensitive linkers designed to undergo selective hydrolysis at acidic pH compared to physiological pH can be used for the selective release of therapeutics at their site of action. In this paper, the hydrolytic cleavage of a wide variety of molecular structures that have been reported for their use in pH-sensitive delivery systems was examined. A wide variety of hydrolytic stability profiles were found among the panel of tested chemical functionalities. Even within a structural family, a slight modification of the substitution pattern has an unsuspected outcome on the hydrolysis stability. This work led us to establish a first classification of these groups based on their reactivities at pH 5.5 and their relative hydrolysis at pH 5.5 vs. pH 7.4. From this classification, four representative chemical functions were selected and studied in-vitro. The results revealed that only the most reactive functions underwent significant lysosomal cleavage, according to flow cytometry measurements. These last results question the acid-based mechanism of action of known drug release systems and advocate for the importance of an in-depth structure-reactivity study, using a tailored methodology, for the rational design and development of bio-responsive linkers.
A total synthesis of hydroxylysine in protected form and investigations of the reductive opening of p-methoxybenzylidene acetals
Gustafsson, Tomas,Schou, Magnus,Almqvist, Fredrik,Kihlberg, Jan
, p. 8694 - 8701 (2007/10/03)
A synthesis of (2S,5R)-5-hydoxylysine, based on (R)-malic acid and Williams glycine template as chiral precursors, has been developed. This afforded hydroxylysine, suitably protected for direct use in peptide synthesis, in 32% yield over the 13-step sequence. Regioselective reductive opening of a p-methoxybenzylidene acetal and alkylation of the Williams glycine template were key steps in the synthetic sequence. Surprisingly, the regioselectivity in opening of the p-methoxybenzylidene acetal was reversed as compared to what was expected. It was found that this was due to chelation of the trialkylsilyl choride, used as an electrophile in the reductive opening, to an adjacent azide functionality. It was also discovered that an equivalent amount of trialkylsilyl hydride was formed in the reaction, a finding that led to additional mechanistic insight into reductive openings of p-methoxybenzylidene acetals with sodium cyanoborohydride as reducing agent.
