Comments on: What is Mutarotation?

By: Taniya Sharma

Taniya Sharma — Fri, 23 Sep 2022 13:46:36 +0000

Plzz discuss the mechanism when rate of mutarotation islow in D2o than in H20 .

By: James Ashenhurst

James Ashenhurst — Thu, 11 Aug 2022 20:56:11 +0000

In reply to Tanya. If it's not soluble, I don't know how useful the technique of mutarotation will be. Usually I would think that they would digest it with acid or similar to bread down the polysaccharide into smaller, more soluble chunks.

By: Tanya

Tanya — Thu, 11 Aug 2022 14:44:46 +0000

Thanks James. What do they do for structural carbohydrates that are insoluble?

By: James Ashenhurst

James Ashenhurst — Thu, 11 Aug 2022 14:41:22 +0000

In reply to Tanya. hi Tanya. Several hours. However, it's going to be solvent-dependent (more polar = faster) and also sensitive to the presence of acids and bases (which will speed it up). The original observation took several hours for the optical rotation to change. These days most people would just put it in an NMR spectrometer and observe it that way.

By: Tanya

Tanya — Wed, 10 Aug 2022 19:58:13 +0000

How quickly does the mutarotation occur? If I isolated a natural sugar from a mixture and wanted to test how much is alpha vs. beta, how fast would that have to happen?

By: James Ashenhurst

James Ashenhurst — Thu, 04 Aug 2022 17:15:08 +0000

In reply to Anna Meredith.

Maybe this J. Chem. Ed. paper?
https://pubs.acs.org/doi/10.1021/ed086p959

By: Saman Nigar

Saman Nigar — Sat, 14 Nov 2020 14:32:48 +0000

Thank you very much

By: James Ashenhurst

James Ashenhurst — Wed, 17 Jun 2020 20:59:09 +0000

In reply to Wale. Why would you expect them to be the same if one is pure and one is impure?

By: Wale

Wale — Mon, 15 Jun 2020 13:33:21 +0000

will the mutarotation of an impure glucose solution be the same as that of pure?

By: James Ashenhurst

James Ashenhurst — Thu, 11 Jun 2020 16:58:22 +0000

In reply to Tolu. Yes, impurities could dramatically affect the mutarotation of glucose. The rotation values given are for pure compounds, for which an accurate calculation of concentration can be made. If the sample is impure (and especially if it is contaminated with an optically active impurity) the measured number will be way off.