Micromonospora chalcea

L-Digitoxose (53L) and its 4-(9-acetyl derivative are present in a tetrasaccha-ride glycosidically linked in tetrocarcin A, an antibiotic inhibitor of the anti-poptotic Bcl-2 protein family.123 Other tetrocarcins have been isolated from the culture of Micromonospora chalcea KY 11091.124 From another strain of Micromonospora, analogues of tetrocarcin A, called arisostatins A and B, containing isobutanoyldigitoxose instead of acetyldigitoxose were isolated.125... 

Tetronolide, the aglycone of the antitumor antibiotic tetrocarcin from Micromonospora chalcea. has been assigned the unusual spiro-3-acyltetronic acid... 

C11H14N4O4 266.256 Nucleoside antibiotic. Isol. from Strepto-myces tubericidus. Major cytotoxin of Tolypothrix byssoidea. Also prod, by Micromonospora chalcea tubercidica. Constit. of the sponge Caulospongia biflabellata. Antitumour, antifungal and antiviral agent. Nucleoside transporter substrate. Cryst. 

A group of tetronic acid natural products with challenging structural patterns from both synthetic and biosynthetic viewpoints and interesting antibiotic and antitumor properties are the spirotetronic natural products. Tetrocarcin A (TCA) is produced by Micromonospora chalcea NRRL 11289 and possesses a polycyclic... 

Further members of the tetrocarcin complex (E, E, P and F-1) found in the culture broth of Micromonospora chalcea KY 1109 have been Isolated and characterized. They all contain tetronolide and tetronitrose, and in addition, and contain L-digitoxose and F, an uncharacterized 2-deoxy sugar. 

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