B. Bohlendorf et al., Antibiotics from gliding bacteria, 85([not equivalent to]) - Melithiazols A-N: New antifungal beta-methoxyacrylates from myxobacteria, EUR J ORG C, (10), 1999, pp. 2601-2608
From cultures of Melittangium lichenicola, Archangium gephyra and Myxococcu
s stipitatus, thirteen new beta-methoxyacrylate (MOA) fungicides related to
myxothiazols (1) have been isolated. Melithiazols A (2a), D (2b), K (2c),
and L (2d) are characterized by a thiazoline-thiazole system, whereas melit
hiazols B (3a), E (3b), F (3c), G (3d), H (3e), I (3f), M (3g), and N (3h)
are bis(thiazoles). Melithiazol C (4), as the first representative of this
class of compounds, contains only one thiazole ring. The structures were es
tablished on the basis of spectroscopic data, and confirmed in the case of
melithiazol E (3b), including its relative configuration,by an X-ray struct
ure analysis. The absolute configuration of melithiazols A (2a) and B (3a)
was determined by degradation and CD spectroscopy. Antifungal and cytotoxic
activities, inhibition of NADH oxidation, and lipophilicities of melithiaz
ols 2-4, myxothiazols 1, and strobilurin-type compounds are compared.