From cultures of Melittangium lichenicola, Archangium
the basis of spectroscopic data, and confirmed in the case of melithiazol E (3b), including its relative configuration, by an gephyra and Myxococcus stipitatus, thirteen new βmethoxyacrylate (MOA) fungicides related to myxothiazols X-ray structure analysis. The absolute configuration of melithiazols A (2a) and B (3a) was determined by (1) have been isolated. Melithiazols A (2a), D (2b), K (2c), and L (2d) are characterized by a thiazoline-thiazole system, degradation and CD spectroscopy. Antifungal and cytotoxic activities, inhibition of NADH oxidation, and lipophilicities of whereas melithiazols B (3a), E (3b), F (3c), G (3d), H (3e), I (3f), M (3g), and N (3h) are bis(thiazoles). Melithiazol C (4), melithiazols 2-4, myxothiazols 1, and strobilurin-type compounds are compared. as the first representative of this class of compounds, contains only one thiazole ring. The structures were established on [ ] Part 84: Ref. [1] smaller peak was further purified by preparative TLC to [a] GBF, Gesellschaft für Biotechnologische Forschung GmbH, give 2 mg of melithiazol C (4). The yields of 2a and 4 corre-Abteilung Naturstoffchemie spond to a production of 70 and 5 µg/L and correlate well Mascheroder Weg 1, D-38124 Braunschweig, Germany [b] Abteilung Strukturforschung with the initially observed level of antifungal activity.