Teaching structural diversity of hexoses to graduate and postgraduate students: Methods to correlate stereochemistry

Carbohydrates, or in strictly chemical terms, polyhydroxy-aldehydes or ketones represent enormous structural diversity in terms of the arrangement of atoms in space, resulting in hundreds of stereoisomers. Although the chemical properties of most stereoisomers may not be very different, their metabolic fate and utilization in biological systems is significantly different and known to influence the overall carbohydrate metabolism. This dictates the importance of understanding the structures of various stereochemical structures for a biochemist. At graduate level teaching, it is really a challenging task to correlate, connect, and recall all the structures. Conventional teaching methods and standard textbook illustrations seldom enable the learners and instructors to sustain the information for a prolonged period. We, in this article, present a unique approach and introduce sigma notation rules for the correlation of stereochemistry of carbohydrates in order to enhance the understanding of stereochemical structures. © 2019 International Union of Biochemistry and Molecular Biology, 48(1):8-20, 2020.