Associate of Betonicin with Urea from Phlomis regelii

The structure of a base isolated from the aerial part of Phlomis regelii as a solvate of the pyrrolidine alkaloid betonicin with urea in a 1:1 ratio was solved. A three-dimensional framework of intermolecular H-bonds was formed by the betonicin and urea molecules in the crystal. The inclusion of a urea molecule in the complex results in stable heteromolecular associates that persist during isolation of the alkaloid.__________Translated from Khimiya Prirodnykh Soedinenii, No. 1, pp. 46–48, January–February, 2005.