Precise Alkoxyamine Design to Enable Automated Tandem Mass Spectrometry Sequencing of Digital Poly(phosphodiester)s

Abstract

Amajor step towards reliable reading of information coded in the sequence of long poly(phosphodiester)s was previously achieved by introducing an alkoxyamine spacer between information sub-segments.H owever,M S/MS decoding had to be performed manually to safely identify useful fragments of low abundance compared to side-products from the amide-based alkoxyamine used. Here,a lternative alkoxyamines were designed to prevent side-reactions and enable automated MS/MS sequencing.D ifferent styryl-TEMPO spacers were prepared to increase radical delocalization and stiffness of the structure.T heir dissociation behavior was investigated by EPR and best results were obtained with spacers containing in-chain benzyl ring, with no side-reaction during synthesis or sequencing.A utomated decoding of these polymers was performed using the MS-DECODER software, which interprets fragmentation data recorded for each subsegment and realign them in their original order based on location tags.

Stereodivergent Synthesis of Enantiopure Oligomers with Tailored Physical Properties

“…These resulting monodisperse and sequence-defined oligomers/polymers possess intriguing properties that are comparable to natural biomacromolecules. 4,17,28 However, while natural biomacromolecules are chiral and enantiopure, synthetic oligomers/polymers are usually much less structurally precise. Fully controlling the absolute stereochemistry is the ultimate goal of macromolecular synthesis, as it would enable access to vastly more synthetic materials with interesting properties that could surpass natural polymers.…”

Nondestructive Sequencing of Enantiopure Oligoesters by Nuclear Magnetic Resonance Spectroscopy

“…Decoding the information stored in sequence-defined macromolecules also presents a challenge. Most of the current methods for decoding the information stored in sequence-defined polymers rely on destructive techniques such as tandem mass spectrometry, which involves the fragmentation of the parent molecules. − Consequently, these methods inevitably consume the information-storing polymers during each decoding attempt, making large-scale or additional synthesis processes necessary for replenishing the polymers, especially when frequent decoding is required. Therefore, nondestructive methods for sequencing synthetic polymers must be developed for macromolecular media to become practically suitable for information storage. − Recently, nanopore sequencing of oligonucleotides has been adopted for decoding sequence-defined oligomers. − …”