Abstract: | The crystal structures of pseudophomins A and B, with primary structures β‐hydroxydecanoyl–l ‐Leu–d ‐Glu–d ‐allo‐Thr–d ‐Ile–d ‐Leu–d ‐Ser–l ‐Leu–d ‐Ser–l ‐Ile monohydrate, C55H97N9O16·H2O, and β‐hydroxydodecanoyl–l ‐Leu–d ‐Glu–d ‐allo‐Thr–d ‐Ile–d ‐Leu–d ‐Ser–l ‐Leu–d ‐Ser–l ‐Ile monohydrate, C57H101N9O16·H2O, new cyclic lipodepsipeptides isolated from Pseudomonas fluorescens strain BRG100, have been solved. The absolute configuration of pseudophomin A has been determined from anomalous dispersion and the stereochemistry of the β‐hydroxy acid group is R. |