Journal article

Publication year: 2019

Pages: 870-877

Journal: Journal of Natural Products

Volume number: 82

Issue number: 4

ISSN: 0163-3864

DOI Link: https://doi.org/10.1021/acs.jnatprod.8b00928

Publisher: American Chemical Society

Abstract: 
Karamomycins A-C (2-4), the first natural 2-naphthalen-2-yl-thiazole derivatives, were isolated along with a plausible precursor molecule, 1-hydroxy-4-methoxy-2-naphthoic acid (1), uracil, 1-acetyl-beta-carboline, and actinomycin C2 from the culture broth of the terrestrial actinomycete strain GW58/450, identified as Nonomuraea endophytica. These compounds were characterized by analysis of their NMR and mass spectrometry (MS) data; the absolute configurations of 2 and 4 were determined by comparison of C-13 NMR, NOESY, and circular dichroism (CD) spectra with density functional theory (DFT)-calculated data. In karamomycin C (4), the thiazole of 2 is connected to an unusual iminothiazolo[4,3-c][1,4]-thiazepinone, for which we proposed a biosynthetic origin from two cysteine residues. It is closely related to ulbactin F; however, the heterocycle is enantiomeric to the latter and connected to phenol instead of 4-methoxy-l-naphthol. Karamomycins A (2) and C (4) were cytotoxic.

Harvard Citation style: Shaaban, K., Shaaban, M., Rahman, H., Grun-Wollny, I., Kämpfer, P., Kelter, G., et al. (2019) Karamomycins A-C: 2-Naphthalen-2-yl-thiazoles from Nonomuraea endophytica, Journal of Natural Products, 82(4), pp. 870-877. https://doi.org/10.1021/acs.jnatprod.8b00928

APA Citation style: Shaaban, K., Shaaban, M., Rahman, H., Grun-Wollny, I., Kämpfer, P., Kelter, G., Fiebig, H., & Laatsch, H. (2019). Karamomycins A-C: 2-Naphthalen-2-yl-thiazoles from Nonomuraea endophytica. Journal of Natural Products. 82(4), 870-877. https://doi.org/10.1021/acs.jnatprod.8b00928