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The full structures of three chromomycins, A2, A3 and A4

โœ Scribed by M. Miyamoto; Y. Kawamatsu; K. Kawashima; M. Shinohara; K. Nakanishi

Publisher
Elsevier Science
Year
1966
Tongue
French
Weight
293 KB
Volume
7
Category
Article
ISSN
0040-4039

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โœฆ Synopsis

The chromomycins are a group of cancerostatic antibiotics produced by Streptomyces griseus 1) and are undoubtedly closely related to olivomycin 2) and several other antibiotics 3, isolated by various groups.

  1. The principal constituent, chromomycin A3@) is commercially available , while chromomycin A2(a and chromomycin A4(A) are the major byproducts isolated during the manufacture of As. The structures of these three constituents are reported in this communication.

The three chromomycins 5) can be isolated by silica gel chromatography of the chromomycin A mixture using ethyl acetate containing 1% oxalic acid as the solvent, the ratio of A 2, A3 and A4 being roughly 1:8:1.

11 Chromomvcin A3 (1)

A planar structure _4 had previously been derived 6) for chromomycin A3 on grounds of a 11 tetrasaccharide n that was isolated from the alkaline hydrolysate of its "methyl ether!' m. p. 185'. However, subsequent 545

๐Ÿ“œ SIMILAR VOLUMES

Elastic moduli of oriented polymers. III
Elastic moduli of oriented polymers. III. The (๏ฃฟA1๏ฃฟA2๏ฃฟA3๏ฃฟ)n and (๏ฃฟA1๏ฃฟA2๏ฃฟA3๏ฃฟA4๏ฃฟ)n types
โœ Enomoto, S. ;Asahina, M. ๐Ÿ“‚ Article ๐Ÿ“… 1962 ๐Ÿ› John Wiley and Sons โš– 491 KB

## Abstract We have calculated the elastic modulus for polyethylene glycol. It has the magnitude of 4.5 ร— 10^10^ โˆ’ 4.8 ร— 10^10^ dyne/cm.^2^ and it is smaller than the previously calculated values for (๏ฃฟA๏ฃฟ)~__n__~ and (๏ฃฟA~1~๏ฃฟA~2~๏ฃฟ)~__n__~โ€type polymers. The small magnitude is thought to be due to th

SmI2 cleavage of chromomycin A3 sugars
SmI2 cleavage of chromomycin A3 sugars
โœ Kimberly Musa Specht; Christina R Harris; Gary A Molander; Daniel Kahne ๐Ÿ“‚ Article ๐Ÿ“… 1999 ๐Ÿ› Elsevier Science ๐ŸŒ French โš– 157 KB

The CDE-trisaccharide of chromomycin A 3 was cleaved with samarium diiodide and converted to a protected glycal for coupling to an aglycone.

Chromomycinone, the aglycone of chromomy
Chromomycinone, the aglycone of chromomycin A3
โœ M. Miyamoto; K. Morita; Y. Kawamatsu; S. Noguchi; R. Marumoto; K. Tanaka; S. Tat ๐Ÿ“‚ Article ๐Ÿ“… 1964 ๐Ÿ› Elsevier Science ๐ŸŒ French โš– 444 KB

The structure of the chromophore chromomyclnone was deduced as Indicated in the following scheme. Chromomrcin A3 1 CH3COOH, boil 2 hrs Chromomvcinone (CHR) UV same as chromomycin A5 :. Chromophore still intact. Chromomycinone No.34 m.p. 183-135', having a typical naphthoquinone UV spectrum, A",izH 2