Abstract
The structures of usnic acid and tetracycline are determined using deuterium isotope effects on 13C chemical shifts in a water environment. In case of usnic acid this is achieved by synthesizing a more water soluble usnic acid with a PEG linker. In the usnic acid case an enolic b-triketone (C-1, C-14 and C-3) tautomeric equilibrium is at hand below pH 5. At pH 7.4 it exists as a mono anion. In case of tetracycline equilibrium between a zwitter ion and a neutral form is found together with an amide functional group and a hydrogen bonded enolic b-diketone system shifted strongly towards one tautomer.
Originalsprog | Engelsk |
---|---|
Tidsskrift | JSM chemistry |
Vol/bind | 3 |
Udgave nummer | 1 |
Sider (fra-til) | 1014-18 |
Antal sider | 5 |
Status | Udgivet - 14 jan. 2015 |
Emneord
- tautomeri
- structure-function relationship
- NMR
- isotoope effects
- usnic acid
- tetracycline