title: Hydrogen-bond-regulated distinct functional-group display at the inner and outer wall of vesicles.
abstract: A unique supramolecular strategy enables the unidirectional assembly of two bola-shaped unsymmetric π-amphiphiles, NDI-1 and NDI-2, which feature a naphthalene-diimide chromophore connected to nonionic and anionic head groups on opposite arms. The amphiphiles differ only in the location of a hydrazide group, which is placed either on the nonionic or on the anionic arm of NDI-1 and NDI-2, respectively. The formation of hydrogen bonds between the hydrazides, which compensates for electrostatic and steric factors, promotes unidirectional alignment and the formation of monolayer vesicles. The zeta potentials and cation-assisted quantitative precipitation reveal negatively charged and nonionic outer surfaces for NDI-1 and NDI-2, respectively, indicating that hydrogen bonding also dictates the directionality of the monolayer curvature, ensuring that in both cases, the hydrazides remain at the inner wall to benefit from stronger hydrogen bonding where they are in closer proximity. This is reflected in their different abilities to inhibit α-chymotrypsin, which possesses a positively charged surface: NDI-1 induced an inhibition of 80% whereas hardly any inhibition was observed with NDI-2.
authors.affiliation: Polymer Science Unit, Indian Association for the Cultivation of Science, 2A and 2B Raja S. C. Mullick Road, Kolkata, India-700032.
authors.forename: Amrita
authors.initials: A
authors.lastname: Sikder
authors.affiliation: Polymer Science Unit, Indian Association for the Cultivation of Science, 2A and 2B Raja S. C. Mullick Road, Kolkata, India-700032.|Present address: Institute for Technical and Macromolecular Chemistry, University of Hamburg, Bundesstrasse 45, 20146 Hamburg (Germany).
authors.forename: Anindita
authors.initials: A
authors.lastname: Das
authors.affiliation: Polymer Science Unit, Indian Association for the Cultivation of Science, 2A and 2B Raja S. C. Mullick Road, Kolkata, India-700032. psusg2@iacs.res.in.
authors.forename: Suhrit
authors.initials: S
authors.lastname: Ghosh
mesh_terms: D002918:Chymotrypsin / Q000037:antagonists & inhibitors / Q000378:metabolism; D004791:Enzyme Inhibitors / Q000737:chemistry* / Q000494:pharmacology; D006834:Hydrazines / Q000737:chemistry; D006860:Hydrogen Bonding; D007094:Imides / Q000737:chemistry* / Q000494:pharmacology; D015394:Molecular Structure; D009281:Naphthalenes / Q000737:chemistry* / Q000494:pharmacology; D013329:Structure-Activity Relationship
chemical_list: D004791:Enzyme Inhibitors; D006834:Hydrazines; D007094:Imides; D009281:Naphthalenes; C542131:naphthalenediimide; D002918:Chymotrypsin; C117608:alpha-chymotrypsin
keywords: bolaamphiphiles; enzyme inhibition; hydrogen bonding; vesicles