. The actinomycetes. Actinomycetales. This rather nontoxic compound is closely related to the chromophore of the actino- mycins. It is believed to be formed by the condensation of two molecules of (juestio- mycin B (o-aminophenol). The chromophore of the actinomycins is 3-amino-l ,8-dimethylphenoxazone-(2)-di- carboxylic acid-(4,5): COOH COOH N. NH, CHs CH3 In the molecules of the actinomycins, two cyclic five-membered polypeptides are linked to the carboxyl groups. Their composition varies from one actinomycin to the other, as explained in Part B of this book. The opening by alkali treatment
. The actinomycetes. Actinomycetales. This rather nontoxic compound is closely related to the chromophore of the actino- mycins. It is believed to be formed by the condensation of two molecules of (juestio- mycin B (o-aminophenol). The chromophore of the actinomycins is 3-amino-l ,8-dimethylphenoxazone-(2)-di- carboxylic acid-(4,5): COOH COOH N. NH, CHs CH3 In the molecules of the actinomycins, two cyclic five-membered polypeptides are linked to the carboxyl groups. Their composition varies from one actinomycin to the other, as explained in Part B of this book. The opening by alkali treatment of the polypeptide rings produces actinomycinic acids which have no antibacterial activity but some antitumor activities. Some antibiotics other than the actino- mycins are also polypeptides with an aro- matic chromophore. They include Icvomycin, mikamycin A, actinoleukin, and as previously mentioned, cchin om ycin. Oligojieptides A group of closely related substances, the antimycins and blastmycin, have antifungal activity and inhibit electron transport in cytochrome systems. Their molecule is composed of two large moieties, antimycic acid and a neutral fragment. Antimycic acid itself contains two moieties: (1) L-thre- onine, and (2) a substituted salicylic acid fragment. The neutral fragment is composed of a variously substituted furan ring. The following structure has been suggested for these compounds: I O, NH CHO —CO- —OH -NH- CO—O- I -CH I CHOH I CH3 -R R. Aiitimvcic acid O CO I R2 Neutral fragment Blastmycin: R = CH,, ; R, = ( ; R2 = CH2—CH(CH3).> : R = C7H16 ; Ri = H; R2 = CHCH-CH3 I CH:, The various antimycins (there are at least four) probal)ly differ in the structiu'e of the C7H15 fragment. A recent paper (Strong et al., 1960) has modified the concept of the structure of the antimycins. The substituted salicylic acid fragment, present in antimycic acid, is attached to a dilactonic Please note that these images are extracted from s
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