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Inspired by arylamide-based oligomeric foldermers that are stabilized by intramolecular hydrogen bonding, a series of polyamides with intramolecular hydrogen-bonding motifs were synthesized viapolycondensation reactions. These polymers can fold into helical conformation different from their linear control. The chirality of helical conformation can further be tuned viaacid–base complexation using chiral residues. [ABSTRACT FROM AUTHOR]

Our current marine natural product program investigated the second metabolites of an actinomyceteStreptomyces cavourensisYY01-17 originating from the Antarctic ecological niche to discover potential antitumor chemical entities. Two new compounds, along with a known compound, were isolated from the ethyl acetate extract of the fermentation broth of the marine-derived actinomycete, and their structures were elucidated, respectively, as 2(S)-3′-hydroxybutan-2′-yl 2-hydroxypropanoate (1), (E)-3-hydroxy-2,4-dimethylhept-4-enamide (2), and 2-hydroxy-3-methylbutanoic acid (3) on the basis of spectroscopic data interpretation. [ABSTRACT FROM PUBLISHER]

Abstract: Hydrogen bonded arylamide foldamers have been introduced in switchable pseudo[2]rotaxanes and [2]rotaxanes, which also include a cyclobisparaquat(p-phenylene) (CBPQT4+) ring and a ‘dumbbell’ containing tetrathiafulvalene (TTF) and 1,5-dioxynaphthalene (DNP, for rotaxanes). The foldamer size changes through folding and unfolding serve as a steric handle to modulate the mechanical movement of the CBPQT4+ ring along the dumbbell of the pseudo[2]rotaxanes and [2]rotaxanes. By varying the number of the repeating units in the foldamer, the kinetics of the solvent-dependent slippage/deslippage of pseudo[2]rotaxanes and the switching of the ring between TTF and DNP of the [2]rotoxanes can be tuned remarkably, with the time scope ranging from several minutes to several days, in twelve solvents of varying polarity, which have been confirmed by the 1H NMR, UV–vis spectroscopy, and cyclic voltammogram experiments. [Copyright &y& Elsevier]