Stoffwechselprodukte von Mikroorganismen. 251. Mitteilung. Die Esmeraldine A und B, tief grüne Farbstoffe aus Streptomyces antibioticus, Stamm Tü 2706

The Esmeraldines A and B, Green Pigments from Streptomyces antibioticus, Strain Tu 2706 From a strain of Sterptomyces antibioticus, Tu 2706, two dark green substances, the esmeraldines A and B, 4 and 3, respectively, were isolated. The structural elucidation was carried out by spectroscopic comparison with some simpler phenazines obtained from the same organism, saphenamycin (1) and related compounds, and by a series of chemical transformations. Esmeraldin B (3) is the 6-methylsalicylic acid ester, and esmeraldin A (4) a mixture of higher saturated and unsaturated fatty acid esters of esmeraldic acid. The latter is a heterocyclic compound with seven rings and four N-atoms, formally derived by condensation of two phenazine residues of the saphenic acid family. The esmeraldins are mixtures are of diastereoisomers.