Rapid cyclic ion mobility separations of monosaccharide building blocks as a first step toward a high-throughput reaction screening platform for carbohydrate syntheses

Abstract

Herein we present a new high-throughput screening method for carbohydrate syntheses based on cyclic ion mobility spectrometry-mass spectrometry (cIMS-MS)-based separations. We rapidly resolved the α/β anomers for carbohydrates with varying protecting groups after only 5 m of cIMS-MS separation and also detected their respective unwanted anomeric impurities at levels lower than 2%. All experiments were performed in 1 minute of total acquisition time demonstrating our method's high-throughput nature. Our methodology was also extended to the separation of an isomeric mixtures of two protected disaccharides illustrating its utility beyond only monosaccharides. We envision our presented workflow as a first step toward the development of a high-throughput screening platform for the rapid and sensitive detection of α/β anomeric selectivities and for trace isomeric/isobaric impurities.

Fig. 1. 5 m cIMS-MS separations of an equimolar mixture of α/β-d-glucosamine pentaacetate as their [M + Na]⁺ adducts at traveling wave conditions of 375 m s⁻¹ and 17 V (A) and 5 m cIMS-MS separations of an equimolar mixture of methyl 2,3,4,6-tetra-O-acetyl-α/β-d-glucopyranoside as their [M + Na]⁺ adducts at traveling wave conditions of 450 m s⁻¹ and 20 V (B).

Fig. 2. 5 m cIMS-MS separations of individual protected carbohydrate anomers as their [M + Na]⁺ adducts. (A and D): α/β-d-glucose-pentaacetate at traveling wave conditions of 450 m s⁻¹ and 22 V. (B and E): α/β-d-galactose-pentaacetate at traveling wave conditions of 450 m s⁻¹ and 22 V. (C and F): ethyl 2,3,4,6-tetra-O-acetyl-α/β-d-thioglucopyranoside at traveling wave conditions of 450 m s⁻¹ and 25 V.

Fig. 3. 5 m cIMS-MS separations of an equimolar mixture of 4-nitrophenyl α/β-d-galactopyranoside as their [M + Na]⁺ adducts at traveling wave conditions of 500 m s⁻¹ and 20 V.

Fig. 4. 5 m cIMS-MS separations of an equimolar mixture of sucrose octaacetate and α-d-cellobiose octaacetate as their [M + Na]⁺ adducts at traveling wave conditions of 350 m s⁻¹ and 25 V.

Fig. 5. Proposed HTS platform coupling high-throughput ion introduction (e.g., DESI) with high-resolution cIMS-MS separations for rapid screening of impurities and anomeric selectivity.