E-Rhodomycinone

Marschalk alkylation (8, 456). The intramolecular Marschalk alkylation is useful in syntheses of the tetracyclic ring system of the cytostatic anthracycline antibiotics. A bimolecular version of the reaction involves condensation of 1 with glyoxylic acid and alcoholic KOH. The product of this reaction is reduced and esterified to afford 2 in 33% overall yield. Less than 5% of the isomeric product 3 is obtained. 9-Deoxy-e-rhodomycinone 4 is available from 2 in two steps (details not provided). ... 

Sffeptomyces peucetiuj subsp, vinaceus 4-O-Glucutonides of akiavinone and E-rhodomycinone 84... 

Most of these strains, including Streptomyces sp. strain C5 (96), S. peucetius (124), and S. insignis (77), also accumulate large quantities of 8 thodomycinone, a daunorubicin pathway intermediate. Wagner et al. (125) have put forth the theory that C-rhodomyci-none is not a common intermediate in daunorubicin biosynthesis pathways, but a shunt product. They base their conclusions on the ability of 1 i-hydroxylase to utilize a variety of dKferent substrates besides aklavirtone, which is considered by most researcheis to be the natural substrate for this enzyme (221-226). The evidence presented in this chapter most strongly supports the notion that e-rhodomycinone is a direct intermediate of daunorubicin and doxorubicin biosynthesis. 

Figure 17 shows the proposed pathway for conversion of rhodomycin D to daunoru-bicin, doxorubicin, and baumycin Aj/Aj. The reactions and genes governing the biosynthesis of daunorubicin and doxorubicin from e-rhodomycinone have been widely postulated (124—126,176,236.239), but they have not been proven in vitro until very recently (239). 

Dekleva ML, Strohl WR. Biosynthesis of e-rhodomycinone from glucose by Screptomyces C5. Can J Mictobiol 1988 34 1235-1240. 

McGuire JC, Thomas MC. Stroshane RM. Hamilton BK, White RJ. Biosynthesis of dauno-mycin glycosides Role of E rhodomycinone. Antimicrob Agents Chemother 1980 18 454-164. 

A series of e-rhodomycinone glycopyranosides, including those derived from L-fucose, L-rhamnose, and D-ribose and their 2-deoxy analogues, has been synthesized the 3,4-di-0-acetyl-2-deoxy-D-eryt/jro-pentopyranosyl derivative showed... 

The chromatography of phenolic compounds on polyamide was later extensively used for isolation and structure elucidation of various naturally occurring materials [229a]. As examples may be mentioned the tannins of sprucewood bark [248] and Sumac [281] isolation of two hydroxystilbenes from Eucalyptus wandoo [279] resolution of several pharmacologically important plant extracts [294] and of the pigments of beets [613] isolation of various ommochromes [112] and the separation of a mixture of e-rhodomycinone and -isorhodomycinone [100] (see the summarising work of H. Endres and H. Hormann [186]). 

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