| abstract |
Novel polycyclic alkaloids of the formula …<IMAGE>… in which R<1> denotes hydrogen or hydroxyl, R<2> denotes hydrogen or acyl and A and B independently of one another denote C = O or C-OH, where the dashed line symbolises a C = C double bond in the position of the middle bond when A or B are C = O, or in the position of the two outer bonds when A or B are C-OH, a process for the preparation of these compounds by fermentation of a novel microorganism of the species Myxococcus xanthus, the novel microorganism itself, pharmaceutical preparations which contain the novel compounds, and the use of the novel compounds as antibiotics and as tumour-inhibiting agents and for the production of pharmaceutical formulations. |