This journal is copyright Royal Society of Chemistry 2000

Supplementary Data

The Conformations of the Macrolide Antibiotics Erythromycin A,

Azithromycin and Clarithromycin in Aqueous Solution : A ¹H NMR Study

Abida Awan,^a Richard J. Brennan,^a Andrew C. Regan,^b and Jill Barber^a

^aSchool of Pharmacy and Pharmaceutical Sciences, University of Manchester, Manchester, UK

^bDepartment of Chemistry, University of Manchester, Manchester, M13 9PL UK

Table 1 ROESY connectivities for clarithomycin (4 mM) in 50 mM sodium phosphate buffer in D₂O. apparent pH 7.4

Italic script indicates signals attributed to spin diffusion. (This is difficult to eliminate from the desosamine ring without introduction of other artefacts.)

The two halves of the chart represent the two halves of the NMR spectrum in this and the following tables.

Table 2 ROESY connectivities for erythromycin A 9-ketone (total erythromycin A 8 mM) in 50 mM phosphate buffer in D₂O, apparent pH 7.4, 45°C.

Bold upper case script indicates signals attributed to the 8-endo-folded-out conformation.

Upper case italic script indicates signals attributed to the cyclisable conformation.

Lower case italic script indicates signals attributed to spin diffusion.

Table 3 ROESY connectivities for erythromycin A 9,12-hemiacetal (total erythromcyin A 8 mM) in 50 mM phosphate buffer in D₂O, apparent pH 7.4, 45°C.

Table 4 ROESY connectivities for azithromycin (4 mM) in 50 mM phosphate buffer in D₂O, apparent pH 7.4.

Signals indicated in upper case italics may be due to a trace of folded-in azithromcyin.

Signals in lower case italics are attributed to spin diffusion.